Strain gauges allow the measurands force, pressure, torque or strain to be converted into voltage ratios and to be indicated by measuring amplifiers. Precision measurements are preferably carried out at 225 Hz and at voltage ratios of up to 2 mV/V. Bridge standards, which have to be traced back to national standards, are used for the electrical calibration of these measuring amplifiers. More than 15 years ago, in PTB the first measuring arrangement for this purpose has been developed and installed. The present contribution explains the traceability principle of bridge standards, shows the long-term stability of selected bridge standards on the basis of measurement results and brings first investigations into the interchangeability of measuring amplifiers up for discussion.

An analysis of an ion beam produced through sputtering of gold by means of Xenon ions in a CHORDIS ion source was performed. The composition of the extracted ion beam was investigated via mass spectroscopy using a double focussing dipole magnet. From the high resolution mass spectrum the abundance pattern of stable Xe isotopes was varified and the amount of charge transitions from 2+ → 1+ could be estimated. A maximum gold current of 0,8 mA directly behind the ion source was measured.

The increasing accuracy of force transducers and their calibration had two major effects: the chance to better extract the capability of a reference standard machine (compared to a formerly mixed evaluation of machine plus transducer) and on the other hand the need to build up reference standard machines capable to calibrate those high precision transducers. Using the experience of designing force transducers, of constructing calibration machines and of calibrating force within the German Calibration Service (DKD) since 1977 HBM decided to take the challenge. Two new dead-weight force reference standard machines of 2.5 kN and 25 kN have been built up and their best measurement capability of significantly better than 0.01 % has been verified by transfer transducers from HBM´s product range.

The goal of this analysis was to obtain knowledge about the dynamic transmission behaviour of piezoelectric film sensors based on Polyvinylidenefluoride (PVDF). Therefore a crossvalidation to the well-known behaviour of strain gauges based on constantan foils was conducted. The test equipment was composed of a shaker and a test piece with affixed sensors. The test piece was stressed through the connection to a load mass. The film sensors based on PVDF were mounted to the test piece in such a way that the load direction was parallel to the longitudinal axis of the PVDF-material. In this way it was guaranteed that the highest piezo strain constant d31 was mainly used. The output signals of the sensors were measured and the frequency response of the piezo film sensors in relation to the strain gauges were calculated. The results indicated that for frequencies above approx. 250 Hz the piezo film sensor frequency response modulus was a constant value with respect to the strain gauges and that for this frequency range there is the possibility to determine a specific transmission value of the used piezo film sensors similar to the “k-factor” of strain gauges. Furthermore, the high pass filter characteristic of the chosen charge amplifier could be identified.

International force standard machines provide ever increasing accuracy. As a result the requirements for the force transducers used for international comparison measurements are also rising. The development of new force transducers shows that it is possible to reduce their measurement uncertainties. This paper describes the measuring bodies of these force transducers and the necessary selection method. The results of measurements obtained in force calibration machines and in force standard machines are presented.