The New 1 kN·m Torque Standard Machine in National Institute of Metrology, China

Abstract A 1 kN-m deadweight torque standard machine is established in National Institute of Metrology, China. The torque range is 5N·m-1200 N·m. The deadweights utilized in the machine can generate the torque of 1200 N·m, 600N·m, 360N·m, 240N·m, 120N·m and 60 N·m, respectively. The torque can be applied both in clock-wise and counter clock-wise direction in sequencial loading process. The aerostatic bearing is introduced to the torque standard machine in order to eliminate the influence of friction. The symmetric V type rotor and stator are used to provide the reliable support both in axial and radial direction. The material of the lever arm is invar alloy, performing with the minimum deformation with the change of the ambient temperature. The counter torque part will make the precise adjustment to make a horizontal alignment of the lever arm. The relative standard uncertainty of the torque generated by the machine is less than 1e-5.

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Progress toward Système International d'Unités traceable force metrology for nanomechanics

Journal of Materials Research ◽

10.1557/jmr.2004.19.1.366 ◽

2004 ◽

Vol 19 (1) ◽

pp. 366-379 ◽

Cited By ~ 52

Author(s):

Jon R. Pratt ◽

Douglas T. Smith ◽

David B. Newell ◽

John A. Kramar ◽

Eric Whitenton

Keyword(s):

Atomic Force Microscope ◽

Electrostatic Force ◽

Standard Uncertainty ◽

National Standards ◽

Force Balance ◽

Traceability Chain ◽

Relative Standard Uncertainty ◽

Force Sensitivity ◽

Atomic Force ◽

Relative Standard

Recent experiments with the National Institute of Standards and Technology (NIST) Electrostatic Force Balance (EFB) have achieved agreement between an electrostatic force and a gravitational force of 10−5 N to within a few hundred pN/μN. This result suggests that a force derived from measurements of length, capacitance, and voltage provides a viable small force standard consistent with the Système International d’Unités. In this paper, we have measured the force sensitivity of a piezoresistive microcantilever by directly probing the NIST EFB. These measurements were linear and repeatable at a relative standard uncertainty of 0.8%. We then used the calibrated cantilever as a secondary force standard to transfer the unit of force to an optical lever–based sensor mounted in an atomic force microscope. This experiment was perhaps the first ever force calibration of an atomic force microscope to preserve an unbroken traceability chain to appropriate national standards. We estimate the relative standard uncertainty of the force sensitivity at 5%, but caution that a simple model of the contact mechanics suggests errors may arise due to friction.

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Development of 1.6 GPa pressure-measuring multipliers

ACTA IMEKO ◽

10.21014/acta_imeko.v3i2.104 ◽

2014 ◽

Vol 3 (2) ◽

pp. 54 ◽

Cited By ~ 2

Author(s):

Wladimir Sabuga ◽

Rob Haines

Keyword(s):

Finite Element Analysis ◽

Reasonable Agreement ◽

Standard Uncertainty ◽

Feasibility Analysis ◽

Element Analysis ◽

Relative Standard Uncertainty ◽

Pressure Calibration ◽

Relative Standard ◽

New Development ◽

Theoretical Results

Two 1.6 GPa pressure-measuring multipliers were developed and built. Feasibility analysis of their operation up to 1.6 GPa, parameter optimisation and prediction of their behaviour were performed using Finite Element Analysis (FEA). Their performance and metrological properties were determined experimentally at pressures up to 500 MPa. The experimental and theoretical results are in reasonable agreement. With the results obtained so far, the relative standard uncertainty of the pressure measurement up to 1.6 GPa is expected to be not greater than 2·10-4. With this new development the range of the pressure calibration service in Europe can be extended up to 1.5 GPa.

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Detonation Velocity Measurement with Chirped Fiber Bragg Grating

Sensors ◽

10.3390/s17112552 ◽

2017 ◽

Vol 17 (11) ◽

pp. 2552 ◽

Cited By ~ 7

Author(s):

◽

Keyword(s):

Detonation Velocity ◽

Velocity Measurement ◽

Standard Uncertainty ◽

Performance Estimation ◽

Relative Standard Uncertainty ◽

Dual Channel ◽

Explosive Performance ◽

Relative Standard ◽

Chirped Fiber Bragg Grating ◽

Propagation Prediction

Detonation velocity is an important parameter for explosive, and it is crucial for many fields such as dynamic chemistry burn models, detonation propagation prediction, explosive performance estimation, and so on. Dual-channel detonation velocity measurement method and system are described. The CFBG sensors are pasted both on the surface and in the center of the explosive cylinder. The length of CFBG sensors is measured via the hot-tip probe method. The light intensity reflected from the CFBG sensors attached to the explosive is transformed to voltage, and the voltage–time is then measured with the oscilloscope. According to the five experiments results, the relative standard uncertainty of detonation velocity is below 1%.

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UNCERTAINTY OF MEASUREMENT IN THE RESPONSE TEST OF A THYROID MONITOR

Radiation Protection Dosimetry ◽

10.1093/rpd/ncz117 ◽

2019 ◽

Vol 184 (3-4) ◽

pp. 531-534 ◽

Cited By ~ 2

Author(s):

Akira Yunoki

Keyword(s):

Measurement Uncertainty ◽

Radiation Protection ◽

Scintillation Detector ◽

Standard Uncertainty ◽

Uncertainty Of Measurement ◽

Test Device ◽

Response Test ◽

Relative Standard Uncertainty ◽

Detector Distance ◽

Relative Standard

Abstract A test device consisting of an I-131 source, a phantom on a 3D moving table, and a NaI(Tl) scintillation detector on a fixed flat table was developed to carry out response tests of a thyroid monitor. A measurement uncertainty due to variation of configuration of the source and the detector, as well as other factors, was estimated. The estimated relative standard uncertainty of measurement at a source–detector distance of 100 mm, which was deduced to be the optimum, was 1.9%. This is sufficiently small for calibrating a thyroid monitor used for radiation protection.

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Reducing the uncertainty of strain gauge amplifier calibration

ACTA IMEKO ◽

10.21014/acta_imeko.v6i4.396 ◽

2017 ◽

Vol 6 (4) ◽

pp. 69 ◽

Cited By ~ 1

Author(s):

Miha Hiti

Keyword(s):

Strain Gauge ◽

Low Voltage ◽

Reference Value ◽

Calibration Method ◽

Standard Uncertainty ◽

Relative Standard Uncertainty ◽

Voltage Ratio ◽

Relative Standard ◽

Lower Uncertainty

The article presents a method for calibration of strain gauge bridge amplifiers with improved uncertainty in low voltage ratio range. The procedure is based on combining traditional calibration of the amplifier at one point and linearity determination of the rest of the range. Traditional calibration is performed by a calibrated strain gauge bridge simulator at a reference value where measurement uncertainty is adequate, and the linearity is determined by a combinatorial calibration method with lower uncertainty, employing a special resistance circuit. Uncertainty in the lower part of the amplifier range can be significantly improved, resulting in a combined relative standard uncertainty below 2.5x10-5 for the range from 0.04 mV/V to 2.5 mV/V.

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The NIST Johnson Noise Thermometry System for the Determination of the Boltzmann Constant

Journal of Research of the National Institute of Standards and Technology ◽

10.6028/jres.122.046 ◽

2017 ◽

Vol 122 ◽

Cited By ~ 5

Author(s):

Nathan E. Flowers-Jacobs ◽

Alessio Pollarolo ◽

Kevin J. Coakley ◽

Adam C. Weis ◽

Anna E. Fox ◽

...

Keyword(s):

International System ◽

Standard Uncertainty ◽

Boltzmann Constant ◽

Correlated Noise ◽

Johnson Noise ◽

Noise Thermometry ◽

Relative Standard ◽

System Of Units ◽

Johnson Noise Thermometry

In preparation for the redefinition of the International System of Units (SI), five different electronic measurements of the Boltzmann constant have been performed using different Johnson noise thermometry (JNT) systems over the past seven years. In this paper, we describe in detail the JNT system and uncertainty components associated with the most recent National Institute of Standards and Technology (NIST) determination of the Boltzmann constant: k = 1.380642 9(69) × 10−23 J/K, with a relative standard uncertainty of 5.0 × 10−6 and relative offset of −4.05 × 10−6 from the Committee on Data for Science and Technology (CODATA) 2014 recommended value. We discuss the input circuits and the approach we used to match the frequency response of two noise sources. We present new measurements of the correlated noise of the 4 K on-chip resistors in the quantum-accurate, pseudorandom, voltage-noise source, which we used to estimate the correlated, frequency-dependent, nonthermal noise in our system. Finally, we contrast our system with those used in other measurements and speculate on future improvements.

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Validation of a PTB force-balanced piston gauge primary pressure standard

ACTA IMEKO ◽

10.21014/acta_imeko.v10i1.821 ◽

2021 ◽

Vol 10 (1) ◽

pp. 271

Author(s):

Ahmed Salama Hashad ◽

Wladimir Sabuga ◽

Sven Ehlers ◽

Thomas Bock

Keyword(s):

Gas Flow ◽

Rarefied Gas ◽

Operation Mode ◽

Experimental Methods ◽

Effective Area ◽

Standard Uncertainty ◽

Operating Pressure ◽

Pressure Balance ◽

Piston Gauge ◽

Relative Standard

Experimental methods using different pressure standards were applied to verify theoretical results obtained for the effective area of the piston-cylinder assembly (PCA) and for pressures measured with a force-balanced piston gauge (FPG). The theoretical effective area was based on the PCA’s dimensional properties defined via diameter, straightness and roundness measurements of the piston and cylinder, derived by gas-flow modelling using principles of the rarefied gas dynamics, and presented as two values: one obtained for absolute and the other for gauge pressure operation mode. Both values have a relative standard uncertainty of 5×10-6. The experimental methods chosen were designed to cover the entire operating pressure range of the FPG from 3 Pa to 15 kPa. Comparisons of the FPG with three different PTB pressure standards operated in different pressure ranges – a pressure balance, a mercury manometer and a static expansion system – were performed using the cross-float method and by a direct comparison of the generated pressures. For the theoretical and experimental effective area, as well as for pressures generated by the FPG and the reference standards, all the results demonstrated full agreement within the expanded uncertainties of the standards.

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Investigation of High-Temperature Normal Infrared Spectral Emissivity of ZrO2 Thermal Barrier Coating Artefacts by the Modified Integrated Blackbody Method

Materials ◽

10.3390/ma15010235 ◽

2021 ◽

Vol 15 (1) ◽

pp. 235

Author(s):

Tong Zhang ◽

Xuyao Song ◽

Gongjin Qi ◽

Baolin An ◽

Wei Dong ◽

...

Keyword(s):

High Temperature ◽

Thermal Barrier Coating ◽

Radiation Thermometry ◽

Spectral Emissivity ◽

Standard Uncertainty ◽

Thermal Barrier ◽

Normal Spectral Emissivity ◽

Zro2 Coating ◽

Barrier Coating ◽

Relative Standard

Zirconium oxide (ZrO2) is widely used as the thermal barrier coating in turbines and engines. Accurate emissivity measurement of ZrO2 coating at high temperatures, especially above 1000 °C, plays a vital role in thermal modelling and radiation thermometry. However, it is an extremely challenging enterprise, and very few high temperature emissivity results with rigorously estimated uncertainties have been published to date. The key issue for accurately measuring the high temperature emissivity is maintaining a hot surface without reflection from the hot environment, and avoiding passive or active oxidation of material, which will modify the emissivity. In this paper, a novel modified integrated blackbody method is reported to measure the high temperature normal spectral emissivity of ZrO2 coating in the temperature range 1000 °C to 1200 °C and spectral range 8 μm to 14 μm. The results and the associated uncertainty of the measurement were estimated and a relative standard uncertainty better than 7% (k = 2) is achieved.

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Development of certified reference materials for physicochemical analysis. Certified reference solutions for the composition of aqueous aluminum, indium, magnesium, nickel and titanium

Reference materials ◽

10.20915/2077-1177-2018-15-3-23-32 ◽

2019 ◽

Vol 15 (3) ◽

pp. 23-32

Author(s):

I. I. Ermakova ◽

A. V. Ivanov ◽

I. N. Zyablikova ◽

A. N. Shobina

Keyword(s):

Reference Materials ◽

Mass Concentration ◽

Certified Reference Materials ◽

Storage Conditions ◽

Physicochemical Analysis ◽

Standard Uncertainty ◽

Expanded Uncertainty ◽

State Register ◽

Physical Measurements ◽

Relative Standard

This paper presents information on the development and certification of reference materials (CRM) for the composition of aqueous aluminium, indium, magnesium, nickel, and titanium solutions.CRMs are represented by aqueous solutions containing aluminium, indium, magnesium, nickel, and titanium ions. CRMs have been packed into 5, 10 and 25 cm3 glass ampoules, as well as into 50 and 250 cm3 polypropylene vessels. The certified values of metal mass concentrations were established according to the preparation method.The certified value of the mass concentration of metal ions in the CRMs under study is found to vary within the range of 0.95–1.06 g/dm3. Both the relative expanded uncertainty (under k= 2) of the certified mass concentration and the relative standard uncertainty due to instability do not exceed the values of 0.8 % and 0.069 %, respectively. The developed CRMs are shown to have the shelf life of 3 years provided that standard storage conditions are ensured. The developed CRMs are included into the RF State Register of Certified Reference Materials under the following numbers: CRM 11122–2018, CRM 11123–2018, CRM 11124–2018, CRM 11125–2018, and CRM 11126–2018. The CRMs produced by the All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI) are characterized by the values of expanded uncertainty comparable to those of world leaders in the production of similar materials.

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Evaluation of Uncertainty in the Determination of Pesticide Residues in Tea using GC-ECD

Jurnal Kimia Terapan Indonesia ◽

10.14203/jkti.v19i1.326 ◽

2017 ◽

Vol 19 (1) ◽

pp. 18-24

Author(s):

Yohanes Susanto Ridwan ◽

Andreas Andreas ◽

Dyah Styarini ◽

Retno Yusiasih

Keyword(s):

Pesticide Residues ◽

Calibration Method ◽

Standard Uncertainty ◽

Uncertainty Component ◽

Method Performance ◽

Total Uncertainty ◽

Key Indicator ◽

Relative Standard ◽

Calibration Solution ◽

Pesticides Residue

Key indicator of quality in test results is the uncertainty value, which could be evaluated using several common approach. Uncertainty evaluation in a-endosulfan and bifenthrin in Oolong tea, and cypermethrin in green tea using bottom-up approach showed that uncertainty component arising from GC-ECD instrument calibration, method performance i.e. repeatability and recovery were the main contributors to total uncertainty. Uncertainty component arising from weighing, dilution factor, stock standard solution, calibration solution, and moisture correction had no significant effect to total uncertainty, hence they could be neglected. Relative standard uncertainty obtained for all of pesticides residue were 18.23, 10.44, dan 14.98% for a-endosulfan, bifenthrin, and cypermethrin, respectively. Comparison with 2/3 CV Horwitz of 17.33, 10.62, and 12.44% respectively for all pesticide residues indicated that the evaluation of uncertainties were realistic

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