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Reports in Year 2018

No.ReportsSummary
1 Measurement System Validation Procedure for High-Capacity Mass Weighing System -METTLER AX64004 mass comparator This procedure provides laboratory colleagues a reference for evaluating the uncertainty of weighting20 kg and 50 kg.In practical weighing, the double substitution method is adopted to do mass comparison of 20 kg and 50 kg weights. During weighing, the readings of the weighting can be obtained and the mean value and standard deviation can be calculated out by computer, the mass value and uncertainty of the unknown weight can be calculated out from the values of standard weight.
2 Measurement System Validation Procedure for Low Pressure Gas Flow Calibration System - Master Method/MOLBLOC (0.002~40 L/min) The mass flowrate calibration system based on the gravimetric method provides a great benefit to a standard laboratory due to the direct measurements of the fundamental units of mass and time. Thus the thermodynamic properties of the employed gas are not necessary to be measured. Besides, the use of the state-of-the-art mass comparators, balance and timer significantly reduced the measurement uncertainty.

Though metrological beneficial, the gravimetric calibration is very time consuming and technique dependent. Thus, it is not adapted for daily calibrations for meters under test. Consequently, measurement standard based on sonic nozzles (or as an alternative, Laminar Flow Elements), which are traceable to the gravimetric method, were developed to calibrate meters under test.

This document provides an uncertainty analysis for the Gas Flow Calibration System – Piston Prover (System code: F06) using Comparison Method at the Fluid Flow Group of National Measurement Laboratory. The system can perform gas meter calibrations at flowrate of 2 cm3/min to 40 L/min. The uncertainty of the system was analyzed based on the principle of propagation of uncertainty, by which the influence sources out of the measurements, ambient conditions, and employed facilities were all included. While the relative combined Low Pressure standard uncertainty was then obtained by the method of root-sum-squares. Eventually, the relative expanded uncertainty was obtained at the 95 % confidence level by multiplying the relative standard uncertainty by a coverage factor.

 

The applicability of this calibration system is as follows:

Environmental temperature: 22 °C to 24 °C

Upstream pressure of MOLBLOC/MOLBOX1: 350 kPa /450 kPa

Volume flowrate of MOLBLOC/MOLBOX1: 2 cm3/min to 40 L/min

Gas: Air or nitrogen

Combined relative standard uncertainty of volume flow rate is 0.062 % and coverage factor is 1.97.

Relative expanded uncertainty of mass flow rate is 0.13 %.

Combined relative standard
3 Measurement System Validation Procedure for Low Pressure Gas Flow Calibration System -Piston Prover (0.002~40 L/min) Abstract

  This document stated the an uncertainty analysis of the Low Pressure Gas Flow Calibration System—Piston Prover (System code: F06) at the National Measurement Laboratory. This system provided calibration services for gas meter at flow range from 2 cm3/min to 40 L/min (for Dry Air, N2, Ar, O2, CO2) and 20 cm3/min to 40 L/min (for He) using the Volume—Time method.

  Uncertainty analysis based on the propagation of uncertainty approach had been performed for this system. The propagation of uncertainty approach identified significant sources of measurement uncertainty; those sources could be qualified by experiments, instrumentation specifications, educated estimation, and handbook values of uncertainty.  These uncertainty components are combined by the root-sum-square (RSS) and multiplied by a coverage factor to obtain the expanded uncertainty at 95 % confidence level.
4 Measurement System Validation Procedure for Filling Mass Cylinder Gases and Concentration of Gas Mixtures —Syringe Injection Method This procedure provides the laboratory colleague as reference for evaluating the Accuracy of weighing syringes and 5 L ~ 10 L aluminum cylinder and the gravimetric preparation concentration of gas mixtures and its expanded uncertainty. Data obtained for calculation is the result of cylinder weighing using Mettler-Toledo XP26003L,  Mettler-Toledo XP10003S mass comparator or Mettler-Toledo MS205DU semi-micro balances. The weighing capabilities of MS205DU, XP26003L and XP10003S can achieve 82 g, 26100 g and 10100 g respectively, and they have a readability of 0.01 mg, 1 mg and 1 mg, respectively. In practical weighing, the substitution method is adopted to do mass comparison between sample syringe or cylinder (S) and syringe or reference cylinder (R). After several times of repeated weighing, the mass difference between the sample and the reference syringe or cylinder, (S–R), can be calculated, as well as its standard deviation of mean value. By substitution weighing of S and R, we can accurately calculate the mass difference of filled liquid or gas before filling (S0–R) and after filling (S1–R). Preliminary evaluation of sources contributed to measurement uncertainty has been done herein. For gas mixtures preparation, three main factors contribute to the system expanded uncertainty: (1) the uncertainties of the filling mass, (2) the purity uncertainties of the raw materials, and (3) the molecular weights of the gas mixture components. The system belongs to the Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), and the primary system provides metrological traceability for gas concentration measurement. The gas Mixtures and their concentration service range are showed in the following table.
5 Measurement System Validation Procedure for Formaldehyde Gas Analyzer Calibration System This document includes the procedure for the assessment of formaldehyde sensor or analyzer with a dynamic dilution system. This document provides concepts for the evaluation of uncertainties of validation processes performed in our laboratory.  According to the validation method and the corresponding mathematical formula between concentration and associated variables, the components of uncertainty include: 1) standard uncertainty of permeation rate of paraformaldehyde permeation tube, 2) standard uncertainty of moisture permeation from the paraformaldehyde permeation tube, 3) standard uncertainty of molar volume,  4) standard uncertainty of flow rate, 5) standard uncertainty of formaldehyde molar mass. We explains how to evaluate each items listed above, to set the validation range, and to estimate the expanded uncertainty of our system. This document is used as a reference guide for whom that requests our validation services. The procedure can be applied to the validation of formaldehyde sensor or analyzer within the range shown in the range of 1 to 10 ppm.
6 Evaluation Report for Concentration Verification, Homogeneity, and Stability of di(2-ethylhexyl)phthalate in Methanol Gas Chromatography Mass Spectrometry (GC-MS) is applied for concentration verification, homogeneity evaluation, and stability evaluation of di(2-ethylhexyl)phthalate in methanol. The accuracy of concentration was confirmed and checked by comparing the gravimetric concentration value with the analysis value obtained from verification. In addition, we can confirm the homogeneity and stability from the concentration verification. The analysis system belongs to Gravimetric Environmental Hormone Supply and Concentration Certification System (C12), which provides service of Primary Reference Material (PRM) to calibration laboratories and testing laboratories. The service of the system is showed in the following table.
7 Measurement System Validation Procedure for Preparation of Di(2-ethylhexyl)phthalate in Methanol — Gravimetric Method This document provides the laboratory colleagues as the reference to use Mettler Toledo XP205 balance system for measuring the mass of adding di(2-ethylhexyl)phthalate and methanol, calculate the concentration of solution and evaluate its expanded uncertainty. The weighing capability of XP205 can achieve 220 g and has a readability of 0.00001 g. In practical weighing, the ABA substitution method is adopted to do mass comparison between the sample bottle (S) and the reference bottle (R). After several times of repeated weighing, we can calculate the mass difference between the sample bottle and the reference bottle (S - R) and its standard deviation of mean value. Follow the same procedures, we can accurately calculate the mass difference before (S0 - R) and after (S1 - R) solute adding, and the mass difference before (S0 - R) and after (S2 - R) solution adding. Then the mass of adding solute, adding solution and the measurement uncertainties can be calculated. The main factors contributed to the system expanded uncertainty are the uncertainties of solute mass, solution mass and solute concentration. The system belongs to the Gravimetric Environmental Hormone Supply and Concentration Certification System (C12). The service of the system is showed in the following table.
8 Evaluation Report of Concentration Verification of Primary Reference Gas Mixtures GC-TCD/FID, FTIR or Trace Oxygen Analyzer are applied for concentration verification of Primary Standard Gas Mixtures (PSM). The accuracy of PSM concentration (Cw) was confirmed, and checked by comparing the gravimetric concentration value (Cw) with the analysis data obtained from verification, Canal. The difference between Cw and Canal shall fit to criterion of ISO 6142 and ISO 6143. The analysis system belongs to Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), which provide service of Primary Reference Gas Mixtures (PRM) to calibration laboratory and testing laboratory. Concentration of PRM is referred to gravimetric result, Cw, and its expanded uncertainty is the combination of uncertainties calculated from gravimetric and verification results.
9 Measurement System Validation Procedure for Single-Phase AC Electrical Energy Measurement System This technical report describes the calibration uncertainty evaluation for the Single-Phase AC Electrical Energy Measurement System (system code: E18) at National Measurement Laboratory. All uncertainty values stated in this report are calculated according to the "ISO/IEC Guide 98-3:2008, Uncertainty of measurement - Part 3: Guide to the expression of uncertainty in measurement (GUM: 1995)".
10 Measurement System Validation Procedure for Filling Mass Cylinder Gases and Concentration of Gas Mixture – Gravimetric Method This procedure provides the system members as reference for evaluating the accuracy of weighing 5 L ~ 10 L aluminum cylinder and the gravimetric preparation concentration of gas mixtures and its expanded uncertainty. Data obtained for calculation is the result of cylinder weighing using Mettler-Toledo XP26003L or Mettler-Toledo XP10003S mass comparator. The weighing capabilities of XP26003L and XP10003S can achieve 26100 g and 10100 g respectively, and they have a readability of 1 mg. In practical weighing, the substitution method is adopted to do mass comparison between sample cylinder (S) and reference cylinder (R). After several times of repeated weighing, the mass difference between the sample cylinder and the reference cylinder, (S–R), can be calculated, as well as its standard deviation of mean value. Filling sample cylinder with target gas followed by substitution weighing of S and R, we can accurately calculate the mass difference of filled gas before filling (S0–R) and after filling (S1–R). Preliminary evaluation of sources contributed to measurement uncertainty has been done herein. For gas mixtures from gas filling, three main factors contribute to the system expanded uncertainty: (1) the uncertainties of the gas filling mass, (2) the purity uncertainties of the parent gases, and (3) the molecular weights of the gas components. The system belongs to the Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), and the primary system provides metrological traceability for gas concentration measurement.
11 Measurement System Validation Procedure for Absolute Reflectance in the VW Geometry of Spectrophotometric System This document describes the method and the result of uncertainty evaluation in absolute reflectance VW measurement system. It includes the introduction of the system, the principle and procedure of the measurement, and so on. It also consists of the evaluation of the system capability and uncertainty.

  This system is primary standard. the wavelength range is (250 ~ 2500) nm, and under the 95 % confidence level in the measuring range of reflectance (1 ~ 100) %, the expanded uncertainty is 0.15%, and its coverage factor is 1.97.

  This document is subordinated to O05 Spectrophotometric System.
12 Measurement System Validation Procedure for Calibration of the Concentration Analysis of Natural Gas A description is given of the accuracy assessment conducted in calibrating the concentrations of chemical components in nature gas with the calibration system in our laboratory. The uncertainty evaluation for the calibration procedure can be referred to this report.

The component concentration is calibrated by comparing the measurement result of the sample gas to that of the reference standard gas. Reference standard gas and sample gas are analyzed by GC in turn, and the peak areas of individual components in the chromatograms are calculated. For each specific target component, the ratio of the peak areas between the sample gas (BS) and the reference standard gas (BR) is determined (r = BS/BR). Such analytical procedure is repeated three times, and the mean deviation and standard deviation of the three measurements are calculated. Using the preliminarily known information of the reference standard gas, the concentration and uncertainty of each individual component to be calibrated in the sample gas can be evaluated.
13 Measurement System Validation Procedure for Laser Interferometer Mercury Micro-manometer This evaluation report is presented in an effort to evaluate the Laser Interferometer Mercury Manometer for Low Pressure Standard(LIML)in the mechanical laboratory of the National Measurement Laboratory (NML). It introduces the functions of the components and system of the LIML, the principles of measurement and the analysis of errors. Finally, It described the calculation of conventional true pressure and the estimation of the uncertainty of conventional true pressure. This LIML for the model ITRI-CMS LIML1-10-2005 is attached to the low pressure measurement system, and its range is as follows, 1Pa~ 10 kPa and its expanded uncertainty is as follows. U(PHR) =0.08 Pa Calibration and measurement capability is stated as the combined standard uncertainty multiplied by the coverage factor k=2, which for a t-distribution with veff=∞ effective degrees of freedom corresponds to a level of confidence of 95%.
14 Measurement System Validation Procedure for Pitch Standard by Laser Diffractometer This document describes the uncertainty evaluation for measurement of grating pitch specimens by laser diffractometer in Center for Measurement Standards. The system can currently provide the pitch calibration service from 280 nm to 10 μm. The diffractometer is composed of a He-Ne laser at 543 nm, a four- quadrant detector, a vibration isolation system, a precision rotating index table and optical lenses. The calibration is based on the diffraction principle by using Littrow configuration. The average grating is calculated by the laser wavelength and the Littrow’s angles. The analysis of measurement uncertainty is based on the ISO “Guide to the expression of uncertainty in measurement”. The error sources are considered and evaluated. The measurement system currently provides the following capability
15 Measurement System Validation Procedure for Sheet Resistance System The document is the measurement system validation procedure (MSVP) of the sheet resistance measurement system (system code: E27) in the National Measurement Laboratory (NML). Based on the MSVP, we calculate the expanded uncertainty given in the instrument calibration procedure and the calibration reports of the system, and provide the quality assurance design of measurement and the analysis of the source of the errors. The document is the measurement system validation procedure (MSVP) of the sheet resistance measurement system (system code: E27) in the National Measurement Laboratory (NML). Based on the MSVP, we calculate the expanded uncertainty given in the instrument calibration procedure and the calibration reports of the system, and provide the quality assurance design of measurement and the analysis of the source of the errors. The system is used to provide the calibration of silicon sheet resistance standards. According to the methods described in ISO “Guide to the Expression of Uncertainty in Measurement (1995)”, we calculate the measurement capacity of the system and the relative expanded uncertainty of the silicon sheet resistance standards to be calibrated. The measurement capacity of the system for the calibration service is as the following:



Measurement scope: 0.15 W ~ 4000 W



Relative expanded uncertainty: 0.46 %

               (Confidence level = 95 %, Coverage factor k = 2.20)
16 Measurement System Validation Procedure for Quantum Hall Resistance Standard System This document describes the uncertainty analysis method for the calibration of a DC standard resistor with the quantum Hall resistance measurement system (system code: E24). This system maintains the primary standard of DC resistance. The measurement method is based on the quantized resistance produced by the quantum Hall device under low temperature and high magnetic field. The values of the DC standard resistors under test with their measurement uncertainties can be obtained through a direct current comparator (DCC) with statistic processing from such a quantized resistance.

This system provides the measurement on the DC standard resistors of 1 kΩ. The uncertainty analysis is according to the ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995). The following table shows the relative expanded uncertainty, level of confidence, and coverage factor of this system: 

Resistor value:1 kΩ;Relative expanded uncertainty:0.08 μΩ/Ω;Confidence level:95 % ; Coverage factor (k):2
17 Measurement System Validation Procedure for Direct Large Resistance System This document is the assessment report for direct large resistance measurement system (system ID no. E25). The direct large resistance measuring means measurement of resistance at range from 1 Mohm to 100 Mohm . In general, the calibrated instruments which are available to direct large resistance measurement are resistor, multimeter, multifunction calibrator and decade resistor. The measurement method is using precision multimeter to compare the difference of resistance values between unit under test and standard resistor. The standard resistor is calibrated by using Hamon transfer standard10 kohm and its uncertainty (level of confidence  = 95 %)
18 Measurement System Validation Procedurs for Polygons This document states the uncertainty evaluation procedures for the Polygons Calibration System.  By using autocollimators as the measurement standards and based on the principle of “circle closure”, the angular error of each interval of the polygon can be estimated by schematic diagram method. The effects of the influential factors on this calibration system will be considered to estimate the uncertainty according to the ISO “Guide to the Expression of Uncertainty in Measurement”, hereinafter called ISO GUM.  The confidence level of this system is 95 %.  Control charts are developed, in accordance with the NBS SP-676-II, to monitor the stability of this system.  According to the developed control charts, it shows that this system is stable. This calibration system is attached to the Large Angle Calibration System (System code: D07).
19 Measurement System Validation Procedure for Single-Phase AC Power Primary Measurement System This document is the measurement system validation procedure for the Single-Phase AC Power Primary Standard Measurement System (E23) at National Measurement Laboratory . It provides the measurement uncertainty evaluation for the report of instrument calibration technique and calibration reports as well.

A current comparater based power calibrator is used to output a standard power to calibrate unit under test (UUT), the relative error for the UUT is calculated from the readings of the UUT, and the calibration data of the standard power calibrator.

The expanded uncertainty is 15 ~ 43 micro W(h)/VA(h, evaluated at a level of confidence

95 % and the coverage factor k = 2.
20 Measurement Ststem Validation Procedure for Vacuum Gauge Comparative Calibration System The Measurement System Validation Procedure describes the method used to evaluate the uncertainty of vacuum gage calibration system(system code: L01) at CMS/ITRI. The evaluation method is based on the official publication of the ISO/IEC Guide 98-3:2008. The influences of error sources are analyzed while performing the calibration works. The measurement scope and the results of evaluated uncertainty are listed in detail.
21 Measurement System Validation Procedure for Pin Gauge This document is an assessment report on the calibration system of the ping gauge by the Center for Measurement Standards in carrying out the National Measurement Laboratory Project. The calibration system provides the traceability and the calibration service of ping gauge for lengths no longer than 20 mm.

The ping gauge calibration system consists of a Zygo laser telemetric systems, two sets of pin gauge, each set contains four different sizes of pin gauges. While calibrating, the calibrated pin gauge is placed on two adjustable V-Blocks. It is necessary to adjust the V-Block to let the calibrated pin gague to be vertical with the optical beam which is the measurement beam.

The error source analysis and uncertainties are analysed according to ISO/IEC Guide 98-3;2008 published by the International Organization for Standardization (ISO). This assessment report belongs to the (D03) calibration system.
22 Measurement System Validation Report for Absolute Radiometer System This report describes the validation method and system capability of the room temperature absolute radiometer.  The radiometer was designed and established during the technical cooperation between CMS and CSIR (Council for Scientific and Industrial Research).

The main function of this system is to provide the absolute measurement of radiant power in the wavelength range from 300 nm to 9000 nm and the calibration of radiant power responsivity for the optical detector.  The measurement range of the radiant power is from 6 mW to 100 mW.

The system was validated according to the parameter method.  This report presents the sources and correction of the parameters which affect the accuracy of the measurement results.  According to the measurement experience, documentary analysis, and internal comparison, the expanded uncertainty for radiant power measurement in the visible range and in the other range are 0.28 %and the coverage factor of the above uncertainties is 1.99; in the other range, the expanded uncertainty is 0.51 %, and the coverage factor of the above uncertainties is 1.98.  The confidence level is 95 %.  The expanded uncertainties for radiant power responsivity measurement in the visible range and in the other range are 0.30 % and 0.54 %, respectively.  The coverage factor of the above uncertainties is 1.98.  The confidence level is 95 %.Please refer to chapter 3 for the details.
23 Measurement System Validation Procedure for DC 1V-10 V Measurement System This document is an calibration procedure report for DC 1V-10V measurement system (E03) in National Measurement Laboratory (NML). This DC 1V-10V system can be used to calibrate the solid-state dc voltage standards. The unit under test is calibrated by comparing its output voltage to each unit in the system reference group via a redundant measurement design.



The uncertainty analysis is according to ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995). The calibration capability of this calibration system is as followed.



Measurement range: 1 V, 1.018 V, 10 V

Relative expanded uncertainty: 0.3 muV/V

Level of confidence (coverage factor): 95 % (2.13).
24 Measurement System Validation Procedure for the Microwave S-Parameters and Impedance System This document is an assessment report for the microwave S-parameter measurement system (U02), which provides calibration service for microwave devices.



The report evaluates the measurement uncertainties with the Agilent E8361A. The system must be calibrated with appropriate calibration kits before performing any measurement. The post-calibration errors contribute to most of the measurement uncertainty.



The calibration capabilities of this system are as follows.

‧ Measurement Parameters: S11, S22, S21, S12.

‧ Connector Type: APC 3.5, Type N

‧ Measurement Range: 0 to 1 for S11 & S22 (linear), 10 dB to -60 dB for S21 & S12.(Devices with higher attenuation can be measured with the system, but it is not recommended since the uncertainties are higher )

‧ Measurement Frequency Range: 0.010 GHz to 18 GHz for Type N, 0.010 GHz to 26.5 GHz for APC 3.5.

‧ Expanded Uncertainty: refers to the above tables.

‧ Level of Confidence (Coverage Factor): 95 % (2).
25 Measurement System Validation Procedure for Potential Transformer This document is an assessment report on the calibration system of the potential transformer by the Center for Measurement Standards in carrying out the National Measurement Laboratory’s Plan﹒ In this system scheme, differential principle is utilized, the measured data were extracted by potential transformer instrument test system. After comparing the difference of unit under test and standard, the test system calculates the ratio error and phase displacement error and shows them on the panel screen. According to the characteristic and specification of each instrument and traceable data of standard potential transformer, a system quality assurance control method was determined. Also, by referencing the standard procedure stated in ISO/IEC Guide 98-3:2008,Uncertainty of measurement-Part 3: Guide to the Expression of Uncertainty in Measurement(GUM:1995), the system capability and the expanded uncertainty of potential transformer measurement system were declared.



The system capability is listed below:

A. Measurement scope:

Primary voltage: 1 kV ~ 100 kV

Secondary voltage: 10 V ~ 240 V

B. Expanded uncertainty:

Ratio error: 0.0082 %

Angle error: 0.06 mrad

(95% confidence level, coverage factor k=2)
26 Measurement System Validation Procedure for AC-DC Current Transfer System This document is a measurement system validation procedure for the AC current measurement system (system number: E11) in National Measurement Laboratory (NML). It provides the measurement uncertainty evaluation for the report of instrument calibration technique and calibration reports as well. Use Thermal Current Converters (TCCs) as standards to calibrate low current range Thermal Current Converters (mATCCs), AC Current sources/meters, and AC Current shunts.

For currents ranging from 10 micro A ~ 20 A at frequencies ranging from 20 Hz to 100 kHz, the expanded uncertainty is from 11 micro A/A ~ 250 micro A/A, representing a confidence level of approximately 95 % and a coverage factor k =2.
27 Instrument Calibration Technique for high-Capacity Mass Weighing System-METTLER AX64004 Mass Comparator This procedure is a reference for weighing single weight of 20 kg and 50 kg with METTLER AX64004 mass comparator. METTLER AX64004 is an electronic mass comparator with 60 kg maximum weighing range and 0.1 mg resolution. Double substitution method is applied to perform the mass comparisons of 20 kg and 50 kg. During weighing, the readings of the standard and unknown weights can be obtained from the readout of display. After several weighing, the differences between the standard and unknown weights, the mean deviations and the standard deviation can be calculated, and then the mass values and uncertainty of the unknown weights can also be calculated from the value of standard weight.
28 Instrument Calibration Techniques for Gas Meter by Low Pressure Gas Flow Calibration System

-Master Method /MOLBLOC (0.002~40 L/min)
This is the operational guide of the Low Pressure Gas Flow Calibration System (System Number: F06) for calibrating meters by comparison method. The actual mass flowrate is obtained directly from the panel of MOLBLOC/MOLBOX1. The relative deviation is obtained by subtracting the actual flowrate from the apparent flowrate and then divides it with the actual flowrate.

Based on ISO/IEC Guide 98-3: 2008, the flowmeter was estimated of its measurement uncertainty with Type A and Type B evaluations for various uncertainty sources. The standard uncertainties (or relative standard uncertainties) and degrees of freedom of the various sources were evaluated individually, and then combined together to give a combined standard uncertainty (or relative   combined standard uncertainty) and effective degrees of freedom. Finally, an expanded uncertainty (or relative expanded uncertainty), obtained by multiplying the combined standard uncertainty (or relative combined standard uncertainty) with a coverage factor at the 95% confidence level, indicated the measurement capability of the measurement process.

The applicability of this calibration system is as follows:

Environmental temperature : 22 °C to 24 °C

Upstream pressure of MOLBLOC/MOLBOX1: 350 kPa/450 kPa

Volume flowrate of MOLBLOC/MOLBOX1:  2 cm3/min to 40 L/min

Gas: Air or nitrogen

Combined relative standard uncertainty of volume flow rate is 0.062 % and coverage factor is 1.97.

Relative expanded uncertainty of mass flow rate is 0.13 %.

Combined relative standard uncertainty of performance indicator is 0.063 % and coverage factor is 1.97.

Relative expanded uncertainty of performance indicator is 0.13 %.

Combined relative standard uncertainty of mass flow rate is 0.057 % and coverage factor is 1.97.

Relative expanded uncertainty of mass flow rate is 0.12 %.

Combined relative standard uncertainty of performance indicator is 0.059 % and coverage factor is 1.97.

Relative expanded uncertainty of mass flow rate 
29 Instrument Calibration Techniques for Gas Meter by Low Pressure Gas Flow Calibration System-Piston Prover Gas Meter  (0.002~40 L/min) This instrument calibration technique is the operational guide for the calibration of gas meters by Volume—time method. The meter to be calibrated is installed in series with the standard device. With a preset flowrate, the piston prover then collects gas that passes through the meter. During calibration, the temperature, pressure, volume or flowrate for the meter under test, and the temperature, pressure, volume, and time for the calibration system are measured. Based on the above-measured results, the relative deviation, the deviation or the discharge coefficient can be estimated.



Based on ISO GUM, calibration uncertainty of the meter can be evaluated with Type A and Type B evaluations for various uncertainty sources. The standard uncertainties (or relative uncertainties), and degrees of freedom of various sources were evaluated individually, and then combined together to give a combined standard uncertainty (or relative combined standard uncertainty) and effective degree of freedom. Finally, an expanded uncertainty (or relative expanded uncertainty), obtained by multiplying the combined standard uncertainty (or relative combined standard uncertainty) with a coverage factor of 1.97 at 95 % confidence level, gives the uncertainty or relative uncertainty of the measurement process.



The applicability of this calibration system is as follows:

Gas                         : Dry Air, N2, Ar, O2, CO2

Volume flowrate : 2 cm3/min to 40 L/min

Gas                         : He

Volume flowrate : 20 cm3/min to 40 L/min

Pressure upstream of the meter : (100 to 700) kPa

Environmental temperature : (22 to 24) °C

Relative expanded uncertainty of standard mass flowrate: 0.08 % at 95 % confidence level, coverage factor is 1.97.

Relative expanded uncertainty of performance indicator: 0.09 % at 95 % confidence level, coverage factor is 1.97.
30 Instrument Certification Technique for Filling Mass Cylinder Gases and Concentration of Gas Mixtures — Syringe injection Method This document provides the operation procedure and matters of notice for filling mass of cylinder gases and concentration verification of cylinder gas mixtures by using gas tight syringe and Mettler Toledo- MS205DU/XP26003L/XP10003S mass comparator.

During weighing, the mass of syringe or cylinder can be obtained from the balance system with ABA substitution method, and then applied to measure the weights of liquid injection and gas filling. The mass of liquid injected and filling target gas can be calculated out.  This document is part of Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), and the primary system provides metrological traceability for gas concentration measurement.
31 Instrument Certification Technique for Preparation of Di(2-ethylhexyl)phthalate in Methanol — Gravimetric Method This document provides the operation procedures and matters of notice for preparation and concentration verification of di(2-ethylhexyl)phthalate in methanol by using Mettler Toledo XP205 balance system.

During weighing, the mass of preparation bottle can be obtained from the balance system using ABA substitution method. Same procedures are applied to measure the weights of preparation bottle before and after the content adding. Then the mass of adding content can be calculated out. This document is part of Gravimetric Environmental Hormone Supply and Concentration Certification System (C12).
32 Instrument Calibration Technique for Single-Phase AC Electrical Energy Measurement System This technical report describes the calibration procedures for the AC Power Measurement System (system code: E18) of Single-Phase AC Electrical Energy at National Measurement Laboratory. The system equipment, procedures, data analysis, and report templates of the calibrations for single-phase active energy and single-phase reactive energy are described in the report.
33 Instrument Certification Technique for Filling Mass Cylinder Gases and Concentration of Gas Mixture – Gravimetric Method This document provides the operation procedure and matters of notice for filling mass of cylinder gases and concentration verification of cylinder gas mixtures by using Mettler Toledo-XP26003L/XP10003S mass comparator.

During weighing, the mass of cylinder can be obtained from the balance system using ABA substitution method.  Same procedures are applied to measure the weights of cylinder before and after gas filling. Then the mass of filling target gas can be calculated out.  This document is part of Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), and the primary system provides metrological traceability for gas concentration measurement.
34 Instrument Calibration Technique for the Component Concentration of Natural Gas This document describes the procedure that is used to calibrate the component concentration of natural gas by gas chromatography equipped with a TCD or FID detector (GC/TCD, GC/FID). The component concentration is calibrated by comparing the measurement result of the sample gas to that of the reference standard gas. This document contains the description of calibration procedure, apparatus, reference standards, data analysis, and format of report.

This procedure applies to the“Low Carbon Fuel Gas Concentration Measurement System”(C09).
35 Instrument Calibration Technique for Pin Gauge This document describes Pin Gauge calibration system which uses a Zygo 1202B Laser Telemetric System, and two sets of V-block. It is necessary to adjust the calibrated Pin Gauge which is supported with two sets of V-block, to be vertical with the measurement laser. The reading value of the Laser Telemetric System will have a minimum when the adjustment is done appropriately. The reading is modified by temperature effect. The calibration system provides the calibration service of the Pin Gauge.

This document belongs to the D03 calibration system.
36 Instrument Calibration Technique for Spectral Radiant Power Responsivity of Absolute Cryogenic Radiometer System This document is written for the absolute spectral radiant power responsivity calibration with the absolute cryogenic radiometer.  The calibration is based on substitution method.  The monochromator-source is measured with the cryogenic radiometer and optical detector, respectively.  Then the spectral radiant power responsivity of the detector is equal to the output signal of the detector divided by the radiant power measured by the cryogenic radiometer.  This is the primary standard of spectral radiant power responsivity of optical detector.

The measurement capability for Si photodiode is from 280 nm to 1100 nm with uncertainty 0.38 % ~ 3.1 % depending on the wavelength.  The measurement capability for Ge photodiode is from 800 nm to 1700 nm with uncertainty 0.36 % ~ 2.1 % depending on the wavelength.  The coverage factor of the above uncertainty is 1.97 with confidence level of 95 %.  The ability will be expanded to 2500 nm and below 280 nm in the future.  Please refer to chapter 3 of Measurement System Validation Procedure for Spectral Radiant Power Responsivity of Absolute Cryogenic Radiometer System [8.1] for the details of uncertainty source and estimated method.
37 Instrument Calibration Technique in the Specular Reflectance of Spectrophotometric System This document describes the calibration procedure for specular reflectance standard plate at the VW accessory in double-beam monochromator. This is a primary measurement system which measures the material’s absolute reflectance corrected by baseline and reference beam. While performing the total and zero reflectance, there would be a baseline factor, and then the reflectance can be measured directly. Finally, the measured value showed is corrected by reference beam further.

  This system is primary standard. the wavelength range is (250 ~ 2500) nm, and under the 95 % confidence level in the measuring range of reflectance (1 ~ 100) %, the expanded uncertainty is 0.15%, and its coverage factor is 1.97.

  This document is subordinated to O05 Spectrophotometric System.
38 Instrument Calibration Technique for Optical Power by Absolute Cryogenic Radiometer System This document describes the procedures of optical radiant power calibration for the standard sources with the absolute cryogenic radiometer system (O07).  The calibration procedures, data analysis, and example of calibration report are illustrated as a working guide.  The technique of the measurement system is based on the electrical substitution method which means the optical radiant power is traced to the electric standard.  This system is the primary standard of radiometry measurement which measuring the optical radiant power under the temperature of 4 K ~ 5 K.

The measurement capabilities of wavelength and radiant power are between 200 nm to 5000 nm, and 10 nW to 1 mW, respectively. The relative expanded uncertainty is 0.026 % for laser source and 0.037 % for monochromator source.  The coverage factor is 1.97 for the 95 % confidence level.
39 Instrument Calibration Technique for LDV System-Standard Spinning Disc Method A non-intrusive Laser Doppler Velocimetry (LDV) with appropriate signal processing system is employed as the calibration standard in air speed calibration system at the National Measurement Laboratory (NML). The fringe spacing of LDV system can be calibrated by measuring the velocity of a standard spinning disc.



This instrument calibration technique is the operational guide of the Air Speed Calibration System for the calibration of LDV system by standard spinning disc.



Based on ISO/IEC Guide 98-3:2008, calibration uncertainty of the LDV system is evaluated with Type A and Type B evaluation for various uncertainty sources. The standard uncertainties and degrees of freedom of various sources are evaluated individually, and then combined together to give a combined standard uncertainty and effective degree of freedom. Finally, an expanded uncertainty, obtained by multiplying the combined standard uncertainty with a coverage factor of k at 95 % confidence level, gives the uncertainty of the measurement process.



The applicability of this calibration system is as follows:

Wind speed range: (0.2 to 60) m/s

Temperature Range: (20 to 26) ℃

Calibration medium: Air.

This system belongs to the Air Speed Calibration System (F10).
40 Instrument Calibration Technique for Pitch Standards by Laser Diffractometer This document describes the calibration procedures for grating pitch by laser diffractometer. The system can currently provide the pitch calibration service from 280 nm to 10 μm. The diffractometer is composed of a He-Ne laser at 543 nm, a four- quadrant detector, a vibration isolation system, a precision rotating index table and optical lenses. The calibration is based on the diffraction principle by using Littrow configuration. The average of grating pitch is calculated by the laser wavelength and the Littrow’s angles.
41 Instrument Calibration Technique for Spectroradiometer of Spectroradiometric System This document describes the calibration procedures of spectral radiance lamp. The calibration procedure is performed by substitution method.  That is comparing the test lamp with the standard light source to get the spectral radiance, luminance, chromaticity coordinate and color temperature of the test lamp.  The standard light source is traced to the combination of absolute radiometer (O06), spectral irradiance (O03) and reflectance (O05).  Besides, the system also provides the standard spectral radiance source for the spectroradiometer.  The correction factor of the spectroradiometer is obtained by comparing the readings of the spectroradiometer with the standard spectral radiance source.  This document is subordinated to the Spectroradiometric System (O03).

‧ The luminance range:

5 cd/m2 to 50000 cd/m2

‧Expanded relative uncertainty:1.5 %, coverage factor:1.96, confidence level:95 %
42 Instrument Calibration Technique for Sheet Resistance System This document is the instrument calibration procedure of the sheet resistance calibration system (system code: E27) at National Measurement Laboratory (NML). It is used as the basis of the calibration method and procedure of the silicon sheet resistance standards. It also describes the calibration instruments and equipment of this system and the example of the calibration report. This system is used to provide the calibration of silicon sheet resistance standards, and its measurement capacity for the calibration service is as the following:



         Measurement scope:0.15 W ~ 4000 W



Relative expanded uncertainty:0.46 %

                (Confidence level = 95 %, Coverage factor k = 2.20)
43 Instrument Calibration Technique for Spectral Radiance Standard Lamp of Spectroradiometric System This document describes the calibration procedures of spectral radiance lamp. The calibration procedure is performed by directly method, use calibrated spectroradiometer to calibrate the spectral radiance source to get spectral radiance, luminance, chromaticity coordinates and color temperature of the working standard lamp and test spectral radiance lamp. This document is subordinated to the Spectroradiometric System (O03).



‧Range:

Item Range

Wavelength 380 nm to 780 nm

Luminance 5 cd/m2 to 50000 cd/m2

Spectral radiance 2 μW/(m2·nm·sr) to 2 W/(m2·nm·sr)

Chromaticity coordinates (x, y) (0,0) to (0.9,0.9)

Chromaticity coordinates (u, v) (0,0) to (0.62,0.39)

Correlated

Color temperature  2500 K to 3200 K



‧Uncertainty: (confidence level:95 %)

‧Item:Spectral radiance

Wavelength (nm) Relative expanded uncertainty (%) Coverage factor

380 ≦λ< 390 3.2 2.08

390 ≦λ< 420 2.7 2.03

420 ≦λ< 530 1.9 1.96

530 ≦λ< 780 1.4 1.96



‧Item:Luminance

Relative expanded uncertainty:1.6 %

Coverage factor:1.96



‧Item:Chromaticity coordinates

Item x y u v

Expanded uncertainty 0.0011 0.0009 0.0004 0.0004

Coverage factor 1.97 1.97 1.97 1.97



‧Item:Correlated Color temperature

Expanded uncertainty:8 K

Coverage factor:1.97
44 Instrument Calibration Technique for Quantum Hall Resistance System This instrument calibration technique describes the calibration procedures for the calibration of 1 kΩ standard resistor with the quantum Hall resistance measurement system (system code: E24). This system maintains the primary standard of the DC resistance. The measurement method is based on the quantized resistance produced by the quantum Hall device under low temperature and high magnetic field. The resistance of the DC standard resistors under test with their measurement uncertainties can be obtained through a direct current comparator (DCC) with statistic processing from such a quantized resistance.

This system provides the measurement on the DC standard resistors of 1 kΩ. The uncertainty analysis is according to the ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995). The following table shows the relative expanded uncertainty, level of confidence, and coverage factor of this system:

Resistor value:1 kΩ ; Relative expanded uncertainty (μΩ/Ω) :0.08 ; Level of confidence:95 % ; Coverage factor (k):2
45 Instrument Calibration Technique for Direct Large Resistance System This document is the operation procedure for direct large resistance measurement system(system ID no. E25). The direct large resistance measuring means measurement of resistance at range from 1 Mohm to 100 Mohm. In general, the calibrated instruments which are available to direct large resistance measurement are standard resistor, multimeter, multifunction calibrator and decade resistor. This document describes the calibration theory, method and procedure of these instruments. For multimeter, multifunction calibrator and decade resistor, they are also able to be used to measure the resistance at range from 1 ohm to00 Mohm. This document also includes the calibration procedure of resistance smaller than 1 Mohm.

The main instrument of direct large resistance measurement system is precision multimeter. By using substitution method, the calibrated instrument could be compared to standard reference resistor directly.
46 Instrument Calibration Technique for Polygons This document describes the calibration procedures for polygons with number of faces from 3 to 72. The required equipment for polygon calibration is also stated. The calibration method is based on the principle of "circle closure", i.e. the sum of all the interior angles of a complete circle equals to 360°. The mathematical model of polygon calibration is described. An example of the calibration report is also given. This calibration system is attached to the Large Angle Calibration System (System code: D07).
47 Instrument Calibration Technique for Absolute Radiometer System This report describes the instrument calibration techniques of the room temperature absolute radiometer.  The system was designed based on the DC substitution theory.  That is the optical radiant power is obtained through the substitution of the electrical power and the optical radiant power.  This makes the optical standard trace to the electrical standard.  The absolute radiometer is currently the primary standard of optical power measurement.

The wavelength range and the radiant power range of the system are from 300 nm to 9000 nm and from 6 mW to 100 mW, respectively.  The expanded uncertainty for the visible range is 0.28 %. For other range, the expanded uncertainty is 0.50 %.  The coverage factor of the above uncertainties is 1.97.  The confidence level is 95 %.  For luminance intensity measurement, the range is from 70 cd to 10000 cd.  The expanded uncertainty is 0.8 %, the coverage factor is 1.97, and the confidence level is 95 %.  For illuminance measurement, the range is from 70 lx to 10000 lx.  The expanded uncertainty is 0.7 %, the coverage factor is 1.97, and the confidence level is 95 %.  The above uncertainties do not include the uncertainty from the test samples.
48 Instrument Calibration Technique for Resistance Thermometers This technical document describes the calibration procedures for resistance thermometers in the National Measurement Laboratory.  This calibration system is subordinated to the resistance thermometer measurement system with code of T04.  This calibration system conforms to the International Temperature Scale of 1990 (ITS-90) and its capability of calibration ranges from -70 ℃ to 300 ℃.  The contents give detailed descriptions on the calibration instruments used, calibration principles and calibration steps.
49 Instrument Calibration Technique for DC 1V-10 V System This document is an calibration procedure report for DC 1V-10V system in National Measurement Laboratory (NML). This DC 1V-10V system can be used to calibrate the solid-state dc voltage standards. The unit under test is calibrated by comparing its output voltage to each unit in the system reference group via a redundant measurement design.



The uncertainty analysis is according to ISO/IEC Guide 98-3:2008, Uncertainty of measurement – Part 3: Guide the expression of uncertainty in measurement (GUM:1995). The calibration capability of this calibration system is as followed.



Measurement range: 1V, 1.018V, 10V

Relative Expanded uncertainty: 0.3 μV/V

level of confidence (coverage factor): 95 % (2.13).
50 Instrument Calibration Technique for llluminance Meter of Absolute Radiometer System This document states the calibration procedure for Illuminance Meter and lumi-nous intensity of Absolute Radiometer System O06. Contents illustrate preliminary op-eration of calibration, calibration steps, and post-calibration procedure…etc. The cali-bration items are illuminance meter (lux meter) and chroma meter, which are calibrated by illuiminant A. The system can also be applied to calibrate the luminous intensity of the lamp. The capability for calibration of illuminance meter is as follows :

‧ Illuminance range: 25 lx to 1500 lx

‧ Luminous intensity: 25 cd to 90000 cd

‧ Chromaticity coordinate: 0.0 to 0.9

‧ Correlated color temperture:2500 K to 3200 K

The capability of this system could be renewed when measurement technology improved or equipment retrofitted.
51 Instrument Calibration Techenique for Luminance Meter/ Luminance Colorimeter of Spectroradiometric System This document describes how to use the spectroradiometer or spectral radiance standard lamp to calibrate Luminance Meter/ Luminance Colorimeter for industry.

The present spectral radiance working standard is calibrated by the reference standard lamp which is traced to National Institute Standards and Techonology (NIST). The calibration range is from 5 cd/m2 to 50,000 cd/m2.

This document is subordinated to the Spectroradiometric System (O03).

‧ Range:

Luminance: 5 cd/m2 to 50000 cd/m2

Chromaticity Coordinates: 0.0 ~ 0.9

Correlated Color Temperature: 2500 K至3200 K

‧Expanded relative uncertainty: (confidence level: 95 %)

Luminance: 1.6 %, coverage factor: 1.96

‧Expanded uncertainty: (confidence level: 95 %)

Chromaticity Coordinates: x:0.0011, coverage factor: 1.97

Correlated Color Temperature: 8 K, coverage factor: 1.97
52 Instrument Calibration Technique for AC-DC Current Transfer System This instrument calibration technique report of AC-DC Current Transfer System (System number: E11) describes the procedures to calibrate thermal current converters, alternating current sources, alternating current meters, and alternating current shunts, by using the standard thermal current coverters.

For currents ranging from 10 micro A ~ 20 A at frequencies ranging from 20 Hz to 100 kHz, the expanded uncertainty is from 11 micro A/A ~ 250 micro A/A, representing a confidence level of approximately 95 % and a coverage factor k =2.
53 Instrument Calibration Technique for Potential Transformer Measurement System The document describes the detailed calibration procedure for the potential transformer which serves as the basis on potential transformer measurement. In this system scheme differential principle is utilized. The primary side of the standard potential transformer under test were connected and were from stable voltage source. The Potential Transformer test system extracted the secondary voltage of both transformers. After comparing the difference the test system then calculated the ratio error and phase displacement and showed them on the panel screen.
54 The Advance Infrastructure Development Project of National Measurement Laboratory National Measurement Laboratory R.O.C. (NML), up to the present, has established 134 measurement systems in 17 metrology fields through international technical peer assessment, to provide primary calibration services directly to about 2,000 firms, and to transfer standards and provide secondary calibration services for over 6 million items nationwide annually, and additionally through signing the Mutual Recognition Arrangement (MRA) of the International Committee for Weights and Measures (CIPM) to enable the calibration reports issued by NML to be co-certified by the 98 cosignatory nations and 4 international organizations that further permits Taiwan’s best products to exclude the technical barrier to trade, and then successfully market globally.

The General Conference on Weights and Measures (CGPM) will make decision to redefine the International System of Units (SI) and have new definition of the SI base units around the end of 2018 with the values of certain physical constants, such as the kilogram for mass to be redefined by the Planck constant h, the ampere for electric current by the elementary charge e, the kelvin for temperature by the Boltzmann constant kB, the mole for amount of substance by the Avogadro constant NA.  Thus, we shall cope in time with such new SI definition to prevent our national measurement standards from the broken chain of metrological traceability. For taking mass standard as an example, our national mass standard prototype No. 78, a replica of International Prototype of the Kilogram (IPK) made from platinum iridium alloy, will be downgraded to secondary mass standard immediately after the publishing of the new SI definition.  Consequently, we will face not only the broken chain crisis to affect the national rights and interests if we are not able to build the new mass measurement standard in time to comply with the new SI definition, but also the requisite sending products of our local manufacturers for overseas calibration to other
55 Measurement System Review Summary Report - Static Gravimetric Method Inorganic Element Supply and Certification System (C13) This summary report describes the measurement system review process and related records after the establishment of the “Static Gravimetric Method Inorganic Element Supply and Certification System (C13)”. A measurement system review meeting was held on March 23, 2018 (Fri) and all of the review committee agreed to approve this calibration system to be provided calibration service for external. Center for Measurement Standards (CMS) submitted the “Measurement System Review Report” of this new established “Static Gravimetric Method Inorganic Element Supply and Certification System (C13)” to the Bureau of Standards, Metrology and Inspection (BSMI) for approval to provide calibration service for external on May 29, 2018 (Tue). And BSMI replied to agree the “Static Gravimetric Method Inorganic Element Supply and Certification System (C13)” to be a national metrological standard system on June 8, 2018 (Fri) and this system can provide calibration service for external.

The calibration capability of “Static Gravimetric Method Inorganic Element Supply and Certification System (C13)” is shown in the following table.



Calibration Range: 1000.0 mg/kg

Expanded Uncertainty: 1.5 mg/kg

Calibration Item:Lead Standard Solution
56 The Procedure for Sampling Particle Number Concentration in a Pipeline by Using Differential Mobility Analyzer This article states the procedure for measuring particle diameter and number concentration in a pipeline.
57 Research on the production of three-axis DC magnetic field signal output and alarm system The environmental magnetic field of the semiconductor factory process machine is monitored in real time to ensure that the operator is not exposed to excessive magnetic fields and can monitor the stability of the instrument.

The three-axis DC magnetic field alarm and signal output system has three tri-axial DC magnetic field sensor head modules that provide real-time measurement and display magnetic field range of ±15 G, and also convert the magnetic field measurement value into 4 mA to 20 mA analog signal,transmitted to the control center via SCADA.

The paper describes working principles, planning and design, production installation and calibration measurement methods, which will serve as the basis for subsequent module expansion.
58 Summary of measurement of outgassing rate of microelectronic components We measured the outgas of the micro-sensor used in the vacuum environment,. The micro-sensor can measured the parameters in vacuum chamber. The main purpose is to determine whether the components can be used under specific requirements or not. As the rate of outgassing may affects the entire semiconductor manufacturing process. We used an appropriate vacuum system to determine the rate of outgassing of the micro-sensor under a vacuum chamber environment. The vacuum system included the load-lock chamber and the main vacuum chamber. Under a high vacuum, the pressure was lower than 10-1 Pa. to test micro-sensor electronic element then open the valve of the load-lock chamber which connected to the main chamber; the pressure changes in the process are measured via the known main chamber and the pressure by an ion vacuum gauge. We will get the upper limit of the outgassing rate of micro-sensor. In this paper, we will report the result of these measurements.
59 Final Report of 2018 NML Internal Audit According to section 4.14 of ISO/IEC 17025:2005 and 8.7 of ISO 17034:2016, the laboratory and the reference material producer shall periodically and in accordance with a predetermined schedule and procedure, conduct internal audits of its activities to verify that its operations continue to comply with the requirements of the management system and standards. Therefore, NML implements the internal audit every year to confirm that each department’s operation fits the requirements of NML, ISO/IEC 17025:2005 and ISO 17034:2016. The effectiveness and suitability of NML management system are also ensured in addition. The task items and relevant records of NML internal audit in 2018 are shown as this research report.
60 Measurement procedures and uncertainty analysis for determination of tank volumes of PVTt gas flow calibration facility This document describes measurement procedures and uncertainty analysis for determination of tank volumes of low pressure gas flow calibration facility - pressure, volume, temperature, and time (PVTt) primary flow standard at National Measurement Laboratory (NML, system code: F12). This flow standard measures flow by collecting a steady stream of gas into a tank of known volume during a measured time interval. The collected mass of gas in the tank divided by the collection time is the mass flow rate. The volumetric flow rate can then be determined by dividing the mass flow rate of gas by density of the gas. Two methods are used for determination of the tank volumes, i.e. weighing method and volume expansion method, depended on the dimension of the tank volume.

The uncertainty analysis in this document is referred to ISO/IEC Guide 98-3:2008(GUM)[8.1]. The input quantities that affect the measurand are estimated through either Type A or Type B evaluation. The combined (relative) standard uncertainty of the measurand is then obtained by taking the root-sum square of each (relative) standard uncertainty component multiplied by its sensitivity coefficient. The (relative) expanded uncertainty of the measurand providing an interval of 95 % level of confidence is finally used to indicate the calibration and measurement capability. It is calculated by multiplying the coverage factor, k, which is obtained based on the effective degrees of freedom calculated by Welch-Satterthwaite equation, with the combined (relative) standard uncertainty.
61 Signal-to-noise ratio optimization of X-ray silicon drift detectors The silicon drift detector (SDD) is widely used in X-ray metrology, such as X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy and X-ray reflectometry. During the signal output and input processing section, different X-ray source materials should adjust the signal processing parameter. After receiving the signal, it passes through the signal preamplifier and a signal shaping amplifier. The signal shaping amplifier is divided into a differentiator and an integrator and a voltage gain. The signal parameters include the gain parameter, the slow channel and the fast channel peaking time and the threshold. By adjusting these parameters, the signal to noise ratio will be optimized.
62 The Customer's Satisfaction Report of NML in 2017 This research report was to evaluate the customer’s satisfaction on the calibration services provided by the National Measurement Laboratory, R.O.C. (NML).  In order to evaluate the customer’s satisfaction, a customer satisfactory survey was done to gather valuable opinions and reactions from customers.  Through evaluation, the correspondence between NML’s services and customers’ demands and expectations was examined and identified.  Furthermore, the analysis of the customer satisfactory survey can be used to determine the future directions of calibration service items and to improve the quality of the calibration services.

Through analyzing the data, the average rate of satisfactory degree to the NML’s services was 9.6 out of 10 in 2017.  However, based on the opinions and expectations from customers, NML still had parts of the service items need to be improved.  Therefore, this research report summarizes the opinions and expectations from customers and provides them to the departments of NML for reference.  In addition to improving the unsatisfied service items, NML will provide better quality of the calibration service for customers continuously.
63 2013-2016 NML Customer Analytics Customer Relation Management is a powerful tool to integrate all of the activity about customers. It is convenient to analyze customer information with IT to reply the customers’ demands quickly. The added value between organization and customers was created from the concept of customer orientation. The enterprise needs to organize and realize the controllable information and knowledge from database with data mining technique. Based on the Laboratory Information Management System, we can find the calibration service amount, economic trend, the important customers and so on. The customer classification using Statistical Method, BCG matrix and cluster analysis are also shown in this paper. All of these results are useful for the management to create the policies, the strategies and the perspectives.
64 Evaluation Report of Concentration Verification and Stability of Primary Reference Gas Mixtures (C2H5OH in N2 and VOCs in N2) GC-FID or GC-MS are applied for concentration verification of Primary Standard Gas Mixtures (PSM). The accuracy of PSM concentration (Cw) was confirmed, and checked by comparing the gravimetric concentration value (Cw) with the analysis data obtained from verification, Canal. The difference between Cw and Canal shall fit to criterion of  , based on ISO 6142-1:2015 and ISO 6143:2001. The concentration stability evaluation process is conducted by comparing concentration analysis results between the original PSM prepared by C08 system and the Primary Reference Gas Mixtures (PRM) purchased from foreign national metrology institute (NMI), or between the PSMs prepared regularly by C08 system. Long-term concentration stability of the original prepared PSMs is evaluated by regular repeated analysis every 3 to 6 months to evaluate the shelf time of PSM. The analysis system belongs to Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), which provide service of Primary Reference Gas Mixtures (PRM) to calibration laboratory and testing laboratory. Gas components and concentration service range of PRM is showed in the following table.
65 Report on Concentration Stability Verification of Primary Reference Gas Mixtures(N2O in N2 & H2S in N2) This report describes the procedure that is applied to verify the concentration stability of Primary Standard Gas Mixtures (PSM) including N2O in N2 and H2S in N2. The gas concentration is analyzed by Gas Chromatography equipped with Thermal Conductivity Detector(GC-TCD)and Gas Chromatography equipped with Mass Spectrometry(GC-MS). The expiration date of the PSM is determined based on the concentration analysis value. This report belongs to the “Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System” (C08). The concentration stability evaluation process is conducted by comparing concentration analysis results between the original PSM prepared by C08 system and the Primary Reference Gas Mixtures (PRM) purchased from foreign national metrology institute (NMI), or between the PSMs prepared regularly by C08 system. Long-term concentration stability of the original prepared PSMs is evaluated by regular repeated analysis every 3 to 6 months.
66 Production Guidelines for Certified Reference Material - di(2-ethylhexyl)phthalate in methanol This production guideline for certified reference material, di(2-ethylhexyl)phthalate in methanol, provides the operation procedure of solution preparation, and according to ISO Guide 34:2009, makes a description of the related quality documents and notice in the production procedure for the laboratory colleague.
67 Evaluation Report of Concentration Verification of Primary Reference Gas Mixtures

(N2O in N2 and H2S in N2)
Gas Chromatography equipped with Thermal Conductivity Detector(GC-TCD)and Gas Chromatography equipped with Mass Spectrometry(GC-MS)were applied for concentration verification of N2O in N2 and H2S in N2 Primary Standard Gas Mixtures (PSM). The accuracy of PSM concentration (Cw) was confirmed, and checked by comparing the gravimetric concentration value (Cw) with the analysis data obtained from verification, Canal. The difference between Cw and Canal shall fit to criterion based on ISO 6142-1:2015 and ISO 6143:2001. The analysis system belongs to Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), which provide service of Primary Reference Gas Mixtures (PRM) to calibration laboratory and testing laboratory.
68 Evaluation Report of Concentration Verification of Primary Reference Gas Mixtures(CO+CO2+C3H8/N2 and O2/N2) Gas Chromatography equipped with Thermal Conductivity Detector(GC-TCD)is applied for concentration verification of Primary Standard Gas Mixtures (PSM). The accuracy of PSM concentration (Cw) was confirmed, and checked by comparing the gravimetric concentration value (Cw) with the analysis data obtained from verification, Canal. The difference between Cw and Canal shall fit to criterion of ISO 6142-1:2015 and ISO 6143:2001. The analysis system belongs to Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08), which provide service of Primary Reference Gas Mixtures (PRM) to calibration laboratory and testing laboratory.
69 Report on Concentration Stability Verification of Primary Reference Gas Mixtures(CO+CO2+C3H8/N2 and O2/N2) This report describes the procedure that is applied to verify the concentration stability of Primary Standard Gas Mixtures (PSM) including CO+CO2+C3H8 in N2 and O2 in N2. The gas concentration is analyzed by Gas Chromatography equipped with Thermal Conductivity Detector and Flame Ionization Detector (GC-TCD/FID). The expiration date of the PSM is determined based on the concentration analysis value. This report belongs to the “Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System” (C08). The concentration stability evaluation process is conducted by comparing concentration analysis results between the original PSM prepared by C08 system and the Primary Reference Gas Mixtures (PRM) purchased from foreign national metrology institute (NMI), or between the PSMs prepared regularly by C08 system. Long-term concentration stability of the original prepared PSMs is evaluated by regular repeated analysis every 3 to 6 months.
70 Report on Concentration Stability Verification of Primary Reference Gas Mixtures This report shows procedure applied to evaluate the concentration stability of CO in N2,

CO2 in N2, CH4 in N2, C3H8 in N2, CF4 in N2, SF6 in N2, NO in N2, SO2 in N2, O2 in N2, and CH4 in air Primary Standard Gas Mixtures(PSM). And, how to use GC-TCD/FID(Gas Chromatography equipped with Thermal Conductivity Detector and Flame Ionization Detector), FTIR(Fourier Transform Infrared Spectroscopy) or Trace Oxygen Analyzer to verify the concentration of the PSM in order to evaluate its expiration date. This report belongs to the scope of Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08). By the concentration ratio analysis between original PSM and Primary Reference Gas Mixtures (PRM) purchased from foreign national metrology institute(NMI) or PSM prepared again regularly by C08, estimating the verification concentration value and its measurement uncertainty of the original PSM. Thereafter, with repeated analysis and testing for the PSM every 3 to 6 months once to have a long-term monitoring and checking of its concentration stability.
71 Measurement and Uncertainty Evaluation Procedure for Tube Inside Diameter of Piston Prover The piston prover, one of the low pressure flow calibration facility, is a volumetric calibration device consisting of five precision bore glass tubes and has mercury sealed piston in each tube. When gas flows into the vertical mounted glass tube the piston will move upwards. The collecting time of the imported gas and the displacement of the piston can be decided through the reflected light signals by mercury to start and finish the counting of the timer and the counter of the laser interferometer. With the initial and final gas pressure and the average gas temperature in the glass tube during the calibration, the flow at reference conditions can be calculated.

To perform the calibration, the average diameter of each glass tube (Dm) should be measured along with the evaluation of the measurement uncertainty. Ring gauge sets combined with a LVDT (Linear Variation Differential Transmitter) is used to measure the inside diameters of each tube. Through the product of the average diameter of each glass tube and the displacement of the piston, Ln, given by the laser interferometer, the volume of the collected gas and the corresponding measurement uncertainty can be obtained.

The measurement uncertainty of the inside diameter of the glass tubes is demonstrated in this report according to ISO “Guide to the Expression of Uncertainty in Measurement”.
72 Production Guidelines for Certified Reference Gas Mixtures This production guideline for certified reference gas mixture provides the operation procedure of gas mixture preparation, and according to ISO 17034:2016, makes a description of the related quality documents and notice in the production procedure for the laboratory colleague.
73 Calibration and Measurement Uncertainty Evaluation Procedure for the Weighing Scales of Flow Measurement Systems This document describes the procedure of calibration and measurement uncertainty evaluation for the weighing scales of flow measurement facility at National Measurement Laboratory (NML). The calibration is conducted by applying test loads to the weighing scale under specified conditions and recording the indication. The test loads consist of standard weights of known conventional value of mass and have traceable calibration to the national mass standard. The object of the calibration is the indication provided by the weighing scale in response to an applied load. The value of the load indicated by the weighing scale will be corrected considering the effect of air buoyancy. The indication of each test load from the weighing scale is compared with the corresponding standard weights, and then expressed in terms of the correction coefficient which is the ratio of standard weight to the indication. Finally, the correction coefficients corresponding to specified test loads on the weighing scale are given as the calibration results.

The measurement uncertainty is evaluated according to ISO/IEC Guide 98-3:2008(GUM)[8.1]. The considered uncertainty categories that affect the calibration results are estimated through either Type A or Type B evaluation. The relative combined standard uncertainty of the measurement result is then obtained by taking the root-mean square of each uncertainty component multiplied by its sensitivity coefficient. The relative expanded uncertainty of the measurements providing an interval with a 95 % level of confidence is used to indicate the calibration and measurement capability. It is calculated by multiplying the coverage factor, k, which is obtained based on the effective degrees of freedom calculated by Welch-Satterthwaite equation, with the relative combined standard uncertainty.
74 Bilateral comparison report on the DC voltage standard systems between NML of Taiwan and NML-ITDI of Philippines A bilateral comparison on the DC voltage standard systems between the National Measurement Laboratory (NML) of Taiwan and the National Metrology Laboratory of the Industrial Technology Development Institute (NML-ITDI) of Philippines performed at NML from August 25 to September 14, 2015 is reported. The aim of this comparison is to verify the competence of NML-ITDI in the calibration of DC Voltage Zener Standards at the 1.018 V and 10 V levels. The Normalized Error (En) of the comparison was 0.73 and 0.85 for 1.018 V and 10 V levels, respectively using uncertainties computed at a 95 % level of confidence (k=2).
75 Measurement System Validation Procedure for Preparation of lead Standard Solution ─ Gravimetric Method This document states the laboratory colleagues as the reference to use Mettler Toledo XP205 and Mettler Toledo MS6002TS balance system for measuring the mass of adding lead and nitric acid solution, calculate the concentration of solution and evaluate its expanded uncertainty. In practical weighing, weighing the value of the use of air buoyancy correction items to be corrected , it can get the sample preparation of the solute mass, solution mass and its uncertainty. The uncertainty of the concentration of the preparation solution is: (1) the uncertainty of solute mass, (2) the uncertainty of solution mass, and (3) the uncertainty of solute purity. This system is part of the Static Gravimetric Method Inorganic Element Supply and Certification System (C13). The service of this system is showed in the following table.
76 Measurement System Validation Procedure for Balance This research describes the application for accuracy calibration of Mettler-Toledo XP26003L and XP10003S balance, and provides a basis for evaluation of measurement uncertainties in the calibration performed in our laboratory. According to the calibration method and the corresponding functional relationship between balance and the associated variables, two main components of uncertainty include: (1) the uncertainties of display values of balance, and (2) the uncertainties of standard weights. This document explains how to evaluate each item listed above. The calibration procedure belongs to the Gravimetric High-Pressure Cylinder Gas Mixture Supply and Certification System (C08).
77 Instrument Certification Technique for Preparation of lead Standard Solution ─ Gravimetric Method This document states the operation procedures and matters of notice for preparation and concentration verification of Lead Standard Solution by using Mettler Toledo XP205 and Mettler Toledo MS6002TS balance system.

During the weighing process, the mass of preparation bottle can be obtained from the balance system using air-buoyancy correction factor method. By using this method, the weights of preparation bottle before and after the content adding can also be obtained. Then the mass of adding content can be calculated. This document is a part of Static Gravimetric Method Inorganic Element Supply and Certification System (C13).
78 Instrument Calibration Technique for Balance This document provides the operation procedure and matters of notice for balance calibration in Medical and Chemistry Research Laboratory(G400). This document belongs to the internal calibration procedure for all of the G400 measurement system.
79 Instrument Calibration Technique Coordinate measuring machine This document is the calibration procedures for the coordinate measuring machine (CMM). The cat-eye reflector is mounted on the CMM, and the LaserTRACER traces the movement of the CMM. Thus, the LaserTRACER can measure the length difference between the CMM and the standard sphere implemented in it when the CMM is remained stationary for a short time. The multilateration and Monte Carlo method are used to calculate the LaserTRACER’s position and the accuracy of the CMM.

The measurement system currently provides the following capability.

Ÿ Calibration item: coordinate measuring machine

Ÿ Measurement range: (200~ 10000) mm

Ÿ Expanded uncertainty :

              U = k × uc =1.97 × (0.18 + 6.3 × 10-7 × L)

              Where L: measurement range

Ÿ Confidence level: 95 %.

Ÿ Coverage factor (k): 1.97

Ÿ This document belongs to coordinate measuring machine calibration system
80 Derivation and verification for six geometric error terms of three linear axes machine tool To achieve rapid and automatic analysis of linear-positioning and squareness errors of three-axis machines, a method requiring a single tracking interferometer placed at a single location is proposed. A kinematic model of a three-axis machine was first devised. Subsequently, an optimization algorithm was applied to solve the inverse kinematic problem by defining reasonable initial and boundary conditions. Simulation parameters included geometric errors of the machine, instrument locations, and repeatability of measurement results (definition derived from the ISO 230-1 standard). Results obtained via simulations demonstrate that considering a repeatability of 4 μm, the maximum differences in linear-positioning and squareness are observed to be -0.9 μm/m and 0.2 arcs, respectively, whereas the corresponding maximum standard deviations are 0.28 μm/m and 0.01 arcs. The method has further been verified using a coordinate-measuring machine. Experimental results demonstrate that analyzed parameters show reasonable agreement with simulation results, wherein maximum differences in linear positioning and squareness errors were observed to be 0.7 μm/m and 0.3 arcs, respectively. The total measuring time of a thrice-divided spatial grid was approximately 10 min. The results of the study demonstrate the feasibility of the proposed method in rapidly analyzing geometric errors in three-axis machines.
81 Geometric Property Measurement of Gauge Block Calibration - Phose Counting Research. This paper introduces a gauge block calibration (D02) about hardware and theory. The gauge block calibration was designed and manufactured by National Physics Laboratory (NPL). The gauge block calibration consists of hardware and an optical measuring system. First, the adjustment of laser powers to make the power distribution in the fiber is correct. The optical measuring system is a Twyeen-Green laser interferometer. The interferometer contains two laser sources, a green laser and a red laser. In the theory, the measuring value is calculated by using an integer number and a fraction number. The interference number, an integer number, is calculated by counting interference fringe. The images of five positions technique are captured by using CCD to process the phase reconstruction. The fraction number is calculated by the phase reconstruction. The measuring value is calculated by using an integer number and a fraction number.
82 Production Guidelines for Certified Reference Material – Lead Standard Solution This production guideline for certified reference material, lead standard solution, provides the operation procedure of solution preparation, and according to ISO Guide 34:2009, makes a description of the related quality documents and notice in the production procedure for the laboratory colleague.
83 Evaluation Report for Concentration Verification, Homogeneity and Stability of Lead Standard Solution. Autotitrator is applied for concentration verification, homogeneity evaluation and stability evaluation of Lead Standard Solution. The accuracy of concentration was confirmed and checked by comparing the gravimetric concentration value with the analysis value obtained from verification. In addition, we can confirm the homogeneity from the concentration verification. The analysis system belongs to Static Gravimetric Method Inorganic Element Supply and Certification System (C13), which provides service of Primary Reference Material (PRM) to calibration laboratories and testing laboratories.
84 Water gas concentration analysis technology The gas source used in the AGT temperature system is argon. The uncertainty of the measurement of the average molecular weight of the gas in the resonance chamber is about 30%. Therefore, in addition to providing high-purity argon, it is also required to monitor the amount. Measure the moisture content of argon. In this paper, the micro-water measurement technology is established, and after the purification of the trace water-gas analysis pipeline established in this paper, the maximum water vapor concentration of 105 ppb is estimated at an argon flow rate of 5 sccm (standard milliliter per minute). The corresponding temperature uncertainty is 0.015 mK-0.034 mK.
85 Development of imaging luminnace measurement system on micro-LED array This report is a summary of the works of “Development of Imaging Luminance Measurement System on micro-LED Array”, which is a part of subject of “Research of Measurement Methods of Micro-LED”. This report includes design principles, constructions, and applications of the system. These technologies will be the basis for the measurement, analysis and evaluation of micro-LED or mini-LED arrays.
86 Fiber laser comb based millimeter- wave frequency radio over fiber This technical report introduces the technique for generation of millimeter-wave (mm-wave) over fiber using Er-fiber laser comb with 1 GHz comb spacing. Virtually imaged phase array (VIPA) and grating are used to resolve the 1 GHz spacing comb lines. Two optical fibers are used to pick up two different comb lines. The two comb lines are then combined into an optical fiber and transmitted to a photodiode to generate mm-wave. By choosing proper comb spacing between the two comb lines, 10-70 GHz mm-wave can be generated. This technology can be used in 5G RoF communication. Fiber laser comb can also offer laser sources for all channels in DWDM optical communication. A communication system based on fiber laser comb can seamless connect the optical and 5G mobile communications.
87 One GHz self-referenced Er-fiber laser comb This technical report introduces the technique for 1 GHz self-referenced Er-fiber laser comb. The laser oscillator is mode-locked by SESAM (Semiconductor saturable absorber mirror) amd has a ring cavity. The optical isolator in the cavity can prevent SESAM from the shining of pump laser to avoid its damage. Four stages of Er-fiber amplifier amplify the power to 550 mW and single mode fiber compresses the pulse down to 70 fs. Highly non-linear fiber is used to expand the optical spectrum to octave-spanning. The offset beat signal detected by f-2f technique has a signal-to-noise ratio of 32 dB. The frequency-stabilized repetition rate has a tracking instability of 1.4x10^-13. The residual fluctuation of offset frequency is about 6 mHz, which affects the relative optical frequency fluctuation of 3x10^-17. Therefore, the instability of current fiber laser comb is mainly limited the instability of the repetition rate. Up to now, no report on self-referenced Er-fiber laser comb with repetition rate no less than 1 GHz has ever been published.
88 Introduction of Global Metrology Academy in Technologies of Thermometry Metrology This report mainly introduces the Global Metrology Academy (GMA) in technologies of thermometry metrology, which is organized by Korea Research Institute of Standards and Science (KRISS). GMA has long been committed to sharing knowledge and experience of exchanges in metrology, so the courses is divided into three modules: its first one of MRQ (Mass and Related Quantities), LDM (Length and Dimensional Metrology), and the third one of TH (Thermometry and Humidity).

Thermometer Technologies are focused in this report. The content consists of technical lectures and hands-on exercises, including New SI information, metrology in general, technologies of thermometry, and relating the calibration skills.
89 Design of  phase detector 'Digital phase detector' was made for comparing the phase/frequency between the deviation frequency of the femtosecond fiber laser optical comb and the reference signal and providing an error signal for adjust output of diode laser. The system is composed of Prescaler, ECL Translator, Digital Phase Detector, Low Pass Filter, Differential Amplifier and Buffer. This report includes specifications, design methods and results of each block diagram.
90 Research on Anti-cheating for Current Taximeter This report contains a comparison analysis between the technical specifications of the CNPA 21 taximeter type certification and the current international taximeter specifications. We also collected suggestions from five domestic taximeter manufacturers and four inspection agencies via interviews. Further, we completed data collection and give recommendations for the anti-cheating recommendations for revision of the CNPA 21 specification.
91 2018 BSMI Gas meter test system performance evaluation A total of 5 sets of commercially 6 m3/h gas meters were used for verification. A total of 5 sets of systems including Tainan Branch, Keelung Branch, Taichung Branch and 7th division of BSMI (2 sets). l Most of the system differences are less than 0.2%, the maximum is not more than 0.23%, with the measurement uncertainty of 0.25% En are less than 0.69. l The results of comparison confirm that the 5 sets gas meter test system currently used by the BSMI are consistent.
92 BSMI Gas meter in use performance test report The performance test of the gas meter in use l Select current meter in use (more than 3 years to 10 years). l In conjunction with the BSMI sampling activities, a total of 3193 gas meter were selected. The total number of unqualified is 106, with a pass rate of 96.7%.。For non-conforming gas meter or meter’s deviation is greater than 3% will sent to the CMS (Center of Measurement Standard) for re-testing, this year a total of 58 gas meters were re-tested。
93 BSMI Retrofit and re-test gas meter long running time performance test Retrofit and re-test gas meter long running time performance test l Selected retrofit and re-tested gas meter for long running time performance test. l Selected retrofit and re-tested gas meter (4 m3/h, 6 m3/h each of 5 set) to conduct research. Running at maximum flow rate for 2000 hours, performance tests were compared before and after long time running test. The result was a maximum of 1.39% difference in change between before and after the long time running test. All the gas meter were able to meet the test conformity criterion of 3% after the long time running test. l After the long time running test, all the gas meter’s deviation are smaller than those before the long time running test. In other words, the gas meter has less deviation after long time running test.
94 Acoustic gas thermometer practical structure analysis and operation For the time being, in the low and medium temperature range, to determine the thermodynamic temperature T, several thermodynamic temperature methods are used in national metrology institutes (NMIs), including the acoustic gas thermometry, the Johnson noise thermometry, the dielectric constant thermometry, and the constant volume gas thermometry…etc. Among the above methods, in which the thermodynamic temperature obtained by the acoustic gas thermometry has the smallest measurement uncertainty, and the measurement principle is based on the kinetic theory. The square of the propagation velocity u of the sound in the ideal gas is proportional to the square of the root mean square Vrms of the ideal gas at the thermodynamic temperature T. From the energy point of view, the average kinetic energy of the gas molecule is directly proportional to the thermodynamic temperature T by Boltzmann constant k, so the application of the sound velocity measurement can determine the thermodynamic temperature. This report analyzes and explains the structure of the acoustic gas thermometer, and establishes the operation steps in structural concept to facilitate the establishment of subsequent detailed operational procedures and measurement technology.
95 High Temperature System Assembly and the Operation Procedure of Thermocouples This report describes the installation structure and the operation procedure of high temperature system for thermocouples, evaluating the melting temperature of the eutectic fixed-points by inflection point method,and the eutectic fixed-points of Co-C(1324 °C) and Pd-C(1492 °C) are carried out to the fixed-point calibration of noble metal thermocouples above 1100 °C.
96 High temperature blackbody furnace assembly and operating procedures The reference for installing, operating, and maintaining the blackbody for radiation thermometers in radiation thermometers calibration system, labeled as T01, of the National Measurement Laboratory are described in this document. The operate range of this blackbody is 600 ℃ to 2000 ℃.
97 The operation and measurement technology for liquid-helium-free Quantum Hall Resistance syetem Many National Metrology Institutes (NMIs) worldwide have invested in the related research of the measurement technology for liquid-helium-free Quantum Hall Resistance (QHR). Therefore, National Measurement Laboratory (NML) in Taiwan also has started the related technology development of liquid-helium-free QHR primary system, and the liquid-helium-free QHR system will be set up at NML this December. This technical report will introduce and explain the operation principle of the liquid-helium-free QHR system, as well as the procedures and safety precautions for the system to perform the resistance standard dissemination and calibration.
98 Dissolving process of silicon crystal by tetramethylammonium hydroxide This study demonstrated the dissolving process of silicon crystal by tetramethylammonium hydroxide. Several procedures such as the cleaning process of teflon sample bottles, the surface cleaning process and dissolution process of silicon crystal should be included. It is notable that the possible contamination sources in sample preparation should be prevented and minimized. In addition, the cleanliness of teflon sample bottle, the dissolving condition of silicon crystal, and the mass correction of the air buoyancy should be confirmed and double-checked during the whole dissolving process. The dissolved silicon concentration should be recalculated before it uses since the solvent evaporation may lead to incorrect concentration. This pre-treatment method of silicon crystal can be applied to silicon isotope analysis in the future.
  • Last Updated:2019/09/12
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