Operating Manual PR 9268/60, PR 9268/70
Purpose and application
Seite 8
3.
PURPOSE AND APPLICATION
The electro-dynamic transducers
PR 9268/60
and
PR 9268/70
serve the measurement of
absolute vibrations. They operate on the seismic measurement principle. A measuring coil,
suspended on membrane springs, is the seismic mass of the transducer. On operating
above the resonance frequency, the seismic mass will remain at rest. The relative motion be-
tween the transducer housing and the voice coil generates a voltage signal proportional to
the vibration velocity.
Robust construction and a splash-proof housing of stainless steel permit the use of the trans-
ducer in hostile environments with temperatures up to 200°C. As part of the
epro
- Machine
Monitoring System the transducers are particularly suitable for vibration measurement and
monitoring at machines. The sensitivity of 22.0 mV/(mm/s) enables the transducer to be con-
nected to the
epro
- Machine Monitoring Systems MMS 6000 and MMS 3000 as well as to
devices of the RMS 700 system.
An electric adaption circuitry in the connector offers another sensitivity of 16.7mV/(mm/s)
thus enabling the use of the transducers
PR 9268/60
and
PR 9268/70
as replacement for the
MMG 033 / 1033 sensors and for the use with measuring amplifiers of the MMG family such
as MMG 500, MMG 1000 and of the LM-series of the AEG Kanis product range. The selec-
tion of the electric sensitivity is made by using different connection points in the Harting con-
nector (refer also Fig. 4).
The transducer
PR 9268/60
is specified for vertical mounting (
±
60°) and the
PR 9268/70
for
horizontal direction (
±
30°). If the transducer is to be mounted in a direction different to the
set measuring direction, it is recommended using a lifting current according to the angle de-
viation. This lifting current, adjusted correctly regarding value and polarity, lifts resp. drops the
seismic mass to provide symmetrical motion of the measuring coil between the stops.
An adapter plate for the mechanical adaption to holders of MMG 033 / MMG 1033 transduc-
ers is available as standard accessory (see fig. 3).
