Deadweight Force Standard Machine Research Articles

Metrological characterisation of the (0.2–100) N deadweight force standard machine with digital twin

Metrological characterisation of the (0.2–100) N deadweight force standard machine with digital twin

Optimal Combination Method for Weights Loading of the Deadweight Force Standard Machine

Optimal Combination Method for Weights Loading of the Deadweight Force Standard Machine

Evaluation of small-capacity force transducers using a developed 2 N dead-weight type force standard machine

A 2 N dead-weight type force standard machine (DWM) had been developed at the National Metrology Institute of Japan (NMIJ). Modifications of the force transducers and weight receivers of the DWM improved measurement reproducibility with rotational position change. Two modified small-capacity force transducers with rated capacities of 1 and 2 N could be precisely calibrated according to International Organization for Standardization (ISO) 376. The results showed quite smaller uncertainties in the calibration ranges of 100 mN to 1 N and 200 mN to 2 N than the catalogue accuracies of commercial transducers. The validity of the calibration capability of the 2 N DWM was confirmed by comparing it with a 50 N DWM. The results obtained by two DWMs coincided within the uncertainties of calibration.

Analysis of mechanical properties for the key force transfer components of 2 MN deadweight force standard machine

The good mechanical properties of deadweight force standard machine (DWM) are the basis to ensure the accuracy of its measurement. Aiming at the development of 2 MN DWM, this paper carries out simulation analysis on the key components of the force value transfer process. The analysis results provide constructive suggestions for the development of 2 MN DWM.

Self-calibration of the 1 MN deadweight force standard machine at INRiM

The INRiM 1 MN deadweight force standard machine (DFSM) was installed in 1995. It adopts a binary sequence of ten weights whose combinations generate forces up to 1 MN. The advantage of this system lies in the self-calibration of its weights. The procedure is based on the comparison between two forces generated by a single weight and by a group of smaller weights, nominally equal. After 25 years, a verification of the DFSM was performed. Results are within the declared CMC limits, i.e. a relative expanded uncertainty of 2 × 10<sup>-5</sup>.

NMISA’s new 5 kN deadweight force standard machine

This paper describes NMISA’s new 5 kN deadweight force standard machine. The machine has the capability to generate force in the range 50 N to 5 kN. The machine uncertainty is conservatively estimated at 0.008 % across the entire measuring range. The weights are adjusted according to the gravity value measured in the laboratory. This machine is used for the calibration of force transducers in tension and compression.

Intercomparison between deadweight machines in China and UK up to 1 MN

This paper describes a tripartite comparison at forces of 250 kN, 500 kN, and 1 MN between deadweight force standard machines located at FJIM (China), NIMTT (China), and NPL (UK). Two different transfer standards were used, and the results demonstrated good agreement between the three machines, with <em>E</em><sub>n</sub> values of significantly lower magnitude than one.

Research on the swing and vibration restraint of the 2 MN deadweight machine frame

In this paper, the new 2 MN deadweight force standard machine of FJIM (Fujian Metrology Institute) with an optimal 20 kN frame with swing and vibration restraint is detailed. Load transient response is considered in the design of column, and a mass damper is used to make the frame stable in 3 s. These methods help the machine reach the uncertainty it claimed.

STANDARDS IN FORCE MEASUREMENTS

Force measurement is an important aspect in testing and determining the characteristics of units, machine parts and materials, building materials and structures, the quality of metallurgical products, as well as when assessing the conformity of force and weight transducers. The purpose of this study is to select the optimal procedure and methodology for realization, storage and transferring of the unit size of force in the country, as well as to ensure its traceability to the international system of SI units. This paper analyzes existing methods of realization, storage and transferring of unit size, such as deadweight force standard machines, hydraulic amplification force standard machines, lever amplification force standard machines and systems (groups) of several force transducers (BU system) that can be used as reference by metrological institutes and calibration laboratories. The main principles of operation of the above mentioned machines of realization of a unit of force are considered, including the components of measurement uncertainty and the nature of their origin with the possibility of further consideration in the uncertainty budget. The calibration and measurement capabilities of the world's leading metrological institutions, which maintain different classes of force standard machines for reproducing the size of a unit of force, namely the measurement range, measurement uncertainty, as well as overall dimensions, operating features, etc. are analyzed. The results of the analysis of the disadvantages and advantages of the three main classes of force standard machines for reproducing the size of a unit of force are presented in this article. Conclusions are made on the creation of a national standard of the force unit based on the installation of lever amplification force standard machines, which are based on the analysis of methods of reproduction and transfer of the size of a unit of force, which will occupy positions among the world's leading metrological institutions.

Evaluation of newly developed 50 N dead-weight type force standard machine using tuning-fork type force transducer

A 50 N dead-weight type force standard machine (DWM) was developed by the National Metrology Institute of Japan to expand the lower end of calibration force from 10 N to 1 N. The weights of the DWM consisted of a loading frame and a linkage-weight stack. The loading frame applied a gravitational force of 1 N to a force transducer under calibration. The calibration and measurement capability of the 50 N DWM was verified to be 2 × 10−5 relative using a tuning-fork type force transducer in accordance with ISO 376. The equivalence between the 50 N and 500 N DWMs was confirmed by performing an intralaboratory comparison using the tuning-fork type force transducer. Moreover, the competence of the transducer for the evaluation of DWMs was demonstrated.

Development of 2 N dead-weight type force standard machine

A 2 N dead-weight type force standard machine (2 N DWM) equipped with a balancing mechanism to cancel out the gravitational force acting on the loading frame is developed by National Metrology Institute of Japan (NMIJ), AIST. Removable standard weights are selected in accordance with the calibration force steps and placed onto a weight-loading mechanism. The minimum force that can be realized is 10 mN. The relative expanded uncertainties of the realized forces with coverage factor k = 2 are evaluated as 5.8 × 10−4 and 2.9 × 10−5 at force steps of 10 mN and 200 mN, respectively. Repeatability is evaluated in the range of 100 mN–2 N with the use of a 2 N force transducer. With the development of this standard machine, the force standards disseminated from NMIJ extend down to 10 mN. We believe that our work can further contribute to developments in force standards.

Investigation of a deadweight force standard machine with a 1 mN – 10 N range

<p>A 10 N small force standard machine with air-bearing support has been developed by NIM. Differing from traditional deadweight force standard machines, this machine is equipped with a balance beam supported by air bearing. The weights of the load frame and deadweight hanging system are balanced, and the initial force is extended to 1 mN. Furthermore, there are innovative designs in the load frame and tension force joint. Performance experiments such as sensitivity, repeatability, and rotation effect are carried out. The uncertainty of this machine is evaluated as 1.0×10<sup>-4</sup> (<em>k</em> = 2) in the range of 1 mN – 0.5 N, 4.0 × 10<sup>-5</sup> (<em>k</em> = 2) in the range of 0.5 N – 10 N. The structure of this force standard machine and its key components are introduced in detail. The performance experimental results and uncertainty evaluation are demonstrated in this paper.</p>

Comparison on Force Standard Machines between TÜBİTAK UME and SASO NMCC

Bilateral Comparison on dead weight Force Standard Machines using calibration of force proving instrument was carried out between National Metrology Institute of Turkey (TÜBİTAK UME) and National Measurement and Calibration Center at Saudi Standards, Metrology and Quality Organization of the Kingdom of Saudi Arabia (SASO NMCC). In this comparison, TÜBİTAK UME was pilot laboratory and supplied the travelling standard with force transducers. The bilateral comparison is performed by measuring force values taken from force standard machines located in TUBİTAK UME and SASO NMCC. Three different capacities force transducers were determined for this comparison in prepared technical protocol. The comparison was published BIMP database on GULFMET.M.F-S2 code. The comparison was used in project UME-KV-D3-2.10.6.b code. Each participant used their own measurement standards and applied the direct comparison transfer method at comparison. There is a good agreement between TÜBİTAK UME and SASO NMCC results.

Design for 2 MN dead-weight and build-up hybrid force standard machine

Based on the requirement for high accuracy and large range DWM in China. The paper describes a design of the 2 MN dead-weight and build-up hybrid force standard machine, which would be established by Fujian Province Institute of Metrology, Fuzhou, China. The design has covered 1) main specifications; 2) main construction; 3) Finite Element Analysis (FEA) of key units, etc. It solves the technology defects of counter-force phenomenon existing in traditional DWM through rational weights combination and independent loading of each weights. Setting up a servo control method to ensure the loading speed of the weights is controllable, so as to enhance the accuracy of the machine. The build-up system in the DWM is designed to preload and calibrate the dynamometer less than class 0.05. Besides the auxiliary systems designed make the machine more intelligent and convenient.

Magnetic field influence in deadweight force standard machines: a practical case

The intention of this study is the determination of the influence in uncertainty determination of the possible magnetic interactions in the CEM 500 kN deadweight force standard machine. For this, the magnetic susceptibility of the masses material has been determined as well as the magnetic flux density has been measured in several points. Based on these measurement results a model has been developed to determine the influence of the magnetic interactions with the help of the FEMM software.

NIM’s 100 kN Deadweight Force Standard Machine

A set of 100 kN deadweight force standard machine was developed at National Institute of Metrology (NIM). This machine is capable of realizing force from 1 kN to 110 kN with 1 kN force step both in compression and tension. The machine employs 31 pieces of weights which may be selected optionally to supply force, as a result, there does not exist counter-force during loading process while the machine calibrates the force transducers with different rated capacities. The loading time for each force step is same. The machine is suitable for the type test of load cell in accordance with the international recommendation of OIML R60. This paper introduces the mechanical structure and working principle, the uncertainty evaluation, comparison results with NIM’s other deadweight machines.

Gravitational forces between weights in Force Standard Machines – Simplified analytical and numerical approaches

The gravitational field at the installation site of deadweight force standard machines has been investigated at PTB in the past. For this purpose, the local gravitational acceleration was measured prior to and after the installation of the machines. The effect of the masses of the machine frame and the load masses was simulated for the 200 kN force standard machine (FSM). In this paper, an attempt is made to calculate the gravitational forces between the weights of PTB’s 2 MN force standard machine using simplified analytical and numerical approaches and models. The aim in doing so is to determine the order of magnitude of these forces and to compare them with the force variations that arise due to tidal changes of the local gravitational acceleration.

Miniaturization of a 50 N tuning-fork type force transducer by adopting a simplified Roberval mechanism

A tuning-fork type force transducer of 50N rated capacity was miniaturized and packed into a cylindrical space 70mm in diameter and 92mm in height by adopting a simplified Roberval mechanism. Repeatability and reproducibility of the measured results in different rotational positions of the transducer were within 2×10−5 relative. The mass of the force introduction part was reduced, and this enabled the transducer to be used in an inverted orientation, which is indispensable for the reference force transducers built into force comparators. The new compact force transducer was evaluated in its upright orientation by using a dead-weight type force standard machine and in the inverted orientation by using a force comparator in which an existing massive tuning-fork type force transducer was temporarily adopted asa reference. It was demonstrated that the output of the new force transducer in the inverted orientation coincided with that in the upright orientation within a mean deviation of 3×10−5 relative, after applying nonlinearity compensation.

Force key comparison CCM.F-K2.a.1 (50 kN and 100 kN)

This report describes CIPM key comparison CCM.F-K2.a.1, a key comparison between force standard machines at the national measurement institutes of Argentina (INTI), Spain (CEM), and the United Kingdom (NPL), at generated forces of 50 kN and 100 kN, in the period from 2010 to 2012. Two transducers were used and the force-time profile was strictly controlled, to minimise effects of creep. The final results are linked to the KCRV determined in CIPM Key Comparison CCM.F-K2.a through the use of one common deadweight force standard machine (NPL's 120 kN machine) in the two comparison exercises.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Eccentric Loading Condition Analysis of 1MN Dead Weight Force Standard Machine

With the development of science and technology , the position of the strength measurement[1] in national economic development is more and more important, In recent years, along with the computer technology, electronic technology and the development of numerical control technology, force standard machine also obtained the rapid development[2-6],dead weight force standard machine strength measuring accuracy is the highest power source device by far, in the process of weight loading, considering the axial load affect the performance of the whole machine and in order to guarantee the machine safe and reliable, it is necessary to eccentric loading conditions for mechanical properties analysis.