In this contribution, the new 2 MN deadweight force standard machine of PTB, which was moved from Berlin to Braunschweig and has been completely modernised, is presented. The determination of the mass of the deadweights with a special mass comparator is described. The uncertainty of the machine is theoretically analysed and experimentally verified by force measurement procedures.

Developed, put into practice and used the universal automatic system MABA-2000 for calibration of force measurement devices in accordance to ISO 376-1999, ISO 7500-1999 and manufacturer requirements. The system includes a set of load cells from 1 kN to 5 MN, amplifier DMP-40 (HBM), computer and accessories. Mathematically proved the possibility of calibration in points, which vary from series to series, proved, and confirmed the application of calculation of formulas accuracy deviation and repeatability in accordance to ISO 7500-1999. This approach increases the productivity and simplifies the calibration process. Software MABA-2000 permits to communicate the measurement line “load cell-amplifier-computer” and to perform calibration process on mode ON-LINE: input of the measurement data, indications of the deviations in real time, calculations of the uncertainties, calculations of the calibration results and output of certificate. For calibration by method of Dead Weight a computer automatically selects a set of standard weights as a function of the True Force and value of gravity acceleration. The strict and precise method of the measurement results’ rounding optimizes the value of uncertainty. Calculation of interpolation polynoms of 1st, 2nd, 3rd degree is done automatically too, and does not require additional resources or time. The software MABA-2000 includes also the subroutine for the measurement load rate and calculates uncertainty in accordance to customer requirements.

This paper presents the needs in Mexico for larger ranges in torque calibration. The design of a torque standard to meet, and surpass, those needs are here included. The general design considerations, the layout of the system and the subsystems designed for the torque national standard for 20 k·Nm in Mexico are discussed and included in this paper.

This paper describes measurement of resultant acceleration of motion and gravity in 3D space based on sensing a metallic ball position on elastic layer housed in a spherical shell. Construction of different types of silicon rubber is introduced and their displacements against pressure are calculated by using the Hertz' law. Since the resultant acceleration makes the ball roll toward the direction to find a balanced position in the shell, the center position of the metallic ball is measured. The rubber layer is concentric to the shell and liable to distort so that three proximity sensors of high-frequency oscillation type can detect characteristics of sink versus pressure. We show measurement principle of extracting the acceleration by using the characteristics. Experimental results are shown and compared among various rubbers to have the most appropriate design of the sensor. We got practical data such that angular error less than ±7.4 deg; amount error less than 2.86 x 10^-2 m/s²; force sensitivity 4.9x 10^-2 N; insensible range less than ±3.8 deg; periodic time 95 ms.

The continuous calibration method of force transducer represents a very helpful method since the calibration can be carried out in a short time compared with the step by step method. Another advantage of the continuous calibration method is the possibility of recording the responses of the standard force transducer and the force transducer to be calibrated synchronously. This could be done using two different channels of the displaying device. The disadvantage of this method is the difficulty to define exactly constant certain loads at each loading series during the calibration. The continuous method shows better measurement uncertainty than the step by step method, where as a lot of calibration points are considered in the analysis. One important factor for the results of the continuous calibration method is the response rate. Rates less then 0.08mV/Vs showed good agreement results of the two methods.