3.3.11 Polarization Voltage - BRUEL & KJAER 5998 Service Manual

3.3.11 Polarization Voltage

1. Set the front panel controls on Type 5998 as follows:
2. Use the DVM to check that there is 0 VDC on:
3. Set both front panel Polarization Voltage switches to 200 V.
Caution: Hazardous Live Voltage. The 200 V terminal may deliver a current of
7 mA and can give an electric shock. Do not touch conductive parts connected to the
200 V terminal. When connecting a voltmeter, make the voltmeter connections be-
fore connecting to Type 5998. When disconnecting, disconnect from Type 5998 first.
4. Connect the
5. Connect DVM Hi input to the 200 V terminal.
6. Measure the polarization voltage and adjust using Adj. until the reading is
7. Taking into account that the output impedance of the polarization voltage sup-
8. Set both front panel Polarization Voltage switches to Ext.
*For example, if your DVM has an input impedance of 10 MΩ, the display would read 154 V when the polarization
voltage is 200 V and the output impedance is 3.0 MΩ (using simple potential divider theory).
BI 5044 –11
Control
Gain
Output
HP Filter
Ref.
Polarization Voltage
pin 3 of the Channel A Receiver BNC socket and
pin 3 of the Channel B Transmitter BNC socket.
terminal to the DVM LO input.
200 VDC.
Note: The Polarization Voltage terminals are low impedance. Therefore, no cor-
rection need be made to the DVM reading.
* , measure the voltages on;
ply is 3.0 MΩ
pin 3 of the Channel A Receiver BNC socket and
pin 3 of the Channel B Transmitter BNC socket.
They should give an equivalent voltage
Reciprocity Calibration Apparatus Type 5998
Setting
0
A
20
Off
0
of 200 V
*
Service Manual
Chapter 3 — Checking Procedure
Checking Procedure
3 − 13