Head of Press and Information Office
Dr. Dr. Jens Simon
Phone: +49 531 592-3005
Email:
jens.simon(at)ptb.de
An enhanced dynamic bridge standard for the calibration of dynamic bridge amplifiers has been issued to the "Acoustics and Dynamics" department of the "Mechanics and Acoustics" division. With this standard, this department will be able to develop calibration services for frequency-dependent sinusoidal signals and for particular signal forms – for example for a dynamic signal with a constant bias or for arbitrary, non-sinusoidal signals.
Dynamic measurements of mechanical quantities (such as force, torque and pressure) are commonly used in industry. In nearly all cases, however, dynamic calibration of the measuring chains used is not possible.
With the enhanced dynamic bridge standard (model designation: DynBN-S), it is now possible to dynamically calibrate bridge standards for strain gauge transducers that are part of such a measuring chain. Compared to the initial prototype of the dynamic bridge standard [1], the symmetry of the calibration signal has been improved, and the phase reference, which is accessible separately, is now made available as a buffered and earth-referred signal. This significantly improves the user-friendliness of DynBN-S by ruling out the possibility of an excessive load of internal signals, with the potential risk of a faulty calibration.
Thanks to DynBN-S, the "Mechanics and Acoustics" division will be able to perform dynamic calibrations of strain-gauge bridge amplifiers according to the measurement conditions required by ISO 4965-2 – in which a dynamic signal on a constant bias is stipulated.
For frequencies below 1 kHz, the measurement uncertainties of the dynamic bridge standard are lower than 0.05 % for the voltage ratio and 0.05° for the phase.
Figure 1: The enhanced dynamic bridge standard
Publications:
[1] M. F. Beug, H. Moser, and G. Ramm, “Dynamic bridge standard for strain gauge bridge amplifier calibration,” in Proceedings of the Conference on Precision Electromagnetic Measurements (CPEM), pp. 568-569, 2012
Dr. Dr. Jens Simon
Phone: +49 531 592-3005
Email:
jens.simon(at)ptb.de
Karin Conring
Phone: +49 531 592-3006
Fax: +49 531 592-3008
Email:
karin.conring(at)ptb.de
Physikalisch-Technische Bundesanstalt
Bundesallee 100
38116 Braunschweig