BRUEL & KJAER 2663, Technical Documentation Manual

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Chapter 2 — Operation
Accelerometer Input Connection
Preamplifiers Types 2663 and 2663 B
User Manual
Brüel & Kjær
8
For many measurement situations, isolating the transducer from the test specimen
may not be a convenient solution. Therefore, the preamplifiers contain a grounded/
floating connection which allows the separation of the input and output grounds.
Shown in
Fig.2.3 is a picture of a preamplifier with the side-cover removed. For ease
of access, the grounded/floating connection is mounted on a stand connected to the
circuit. When you remove the jumper connection, the input is set to 'floating' and the
ground loop is broken.
Fig.2.2 Connection of single-ended accelerometer to Type 2663/2663 B using the Microplug-TNC
socket Adaptor Type JJ 0207 with single-screened, low-noise accelerometer cable
Fig.2.3 A section of Type 2663/2663 B’s circuit board is shown with the side-cover removed. The
Floating-Remove Jumper allows you to choose between a grounded or floating connection
For a Single-ended Floating configuration, remove the connection (jumper) between
the two pins on the stand. Note that the 'floating' facility should only be chosen
when the input ground and output ground are externally connected. If there is no
such connection, the 'grounded' configuration should be used.
For a Single-ended Grounded configuration, ensure that there is a good connection
between the two pins on the stand. Use a solder to make the connection.
Vibration Test Specimen
Preamplifier
2663
Single Ended
Accelerometer
plus
Isolating Stud
and Mica Washer
E
D
B
C
A
F
890748e
Input