Brüel & Kjaer Vibro AC-4704 Instructions D'emploi page 7

© Brüel & Kjaer Vibro │Instruction AC-4704
Application
The AC- 4704 is a sensor interface that connects constant current-supplied acceleration sensors
(CCS-sensors, or CCLD, or ICP) to a VI-6080 device. The sensors operate with 8.5 mA.
The four-channel AC-4704 passes the signals on to the VI-6080 via a network cable
(patch cable Cat ...). It should be noted here that the raw signals from the connected sensors are
routed via the patch cable in parallel lines. It is highly recommended to use high-quality network
cables in order to prevent crosstalk from one channel (sensor) to another occurring (e.g. use Cat.6
S/FTP with PiMF or S/STP). This applies in particular to long cable lengths. B & K Vibro provides
these cables in the delivery range (see ordering code).
Take note of the following note, which is fundamentally applicable.
NOTE!
The frequency response of the signal is influenced by the source's output impedance and
the cable capacitance (first-order low-pass).
In the case of a connection where a patch cable to the signal source (buffer) is used, then
the output resistance (R, Ohm) of the source is crucial as is the cable capacitance (C, pF/m)
- which is a function of the cable length.
The following table shows the limit frequency (Hz), which is still to be measured
approximately, for different source output resistances and two different cable lengths in
metres (e.g. 10 m, 100 m).
Output resistance
[buffer/signal source]
100 Ohm
500 Ohm
1,000 Ohm
*B&K Vibro Cat.6 S/FTP with PiMF (raw cable with Cat.7 quality)
1 approx. range of B&K Vibro Type VC-6000
2
approx. range of B&K Vibro Type VC-8000 (Setpoint), Type VC-4000, Type Classic 2520
and Bently Nevada Type 3500
© Brüel & Kjaer Vibro ● 10/2017 ● C106022001 / V05
Technical alterations reserved!
1
2
NOTE!
These operating instructions are
part of the product. Read the
operating instructions carefully
before using the product and keep
the manual safely for future use.
approx. limit frequency
for 10 m patch cable*
~ 1 MHz
~ 200 KHz
~ 120 KHz
EN
Application
approx. limit frequency
for 100 m patch cable*
~ 100 KHz
~ 25 KHz
~ 12 KHz
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