HBM CMD Serie Bedienungsanleitung Seite 71

CMD
Tips for piezoelectric measurement technology
Fig. 14.5 Measuring chain with charge amplifier block diagram
Piezoelectric sensors are ideally suited to dynamic and
non‐zero point‐related measurements. The drift gener­
ated by piezoelectric measurement chains is so low that
it does not affect accuracy even with high requirements.
Drift is an effect of the limited insulation resistance of
cables and charge amplifiers. The transducers them­
selves do not display drift if mounting and connection are
implemented correctly. The maximum drift of a measur­
ing chain with a CMD is 0.1 pC/s or 25 mN/s, if quartz is
used as sensor material, or 13 N/s for the sensor mate­
rial gallium phosphate.
To achieve less drift, please note the following:
- The running‐in behavior of the charge amplifier.
The charge amplifier should warm up for at least a
hour before you start measuring.
- The cleanliness of the connections (free of grease).
A2781-3.1 HBM: public
69