Model 2302-V001
RESISTOMAT
®
Page 23
Brief guide
Operation
Calibration
Test and offset
instructions
RS232 data
output
Introduction &
applications
Description of functions
Accessories and Circuit diagram
These instructions cover the entire procedure of re-calibration. If only small measurement
deviations occur, it is sufficient to just check individual items.
The digital voltmeter can be demounted (by removing the two screws on each side) to allow
easier access to the printed circuit boards. However, the voltmeter must remain connected
to the two plugs otherwise the current circuit will not function.
Required accessories:
Suitable calibration resistances
for the individual ranges, e.g. series
1240.
If possible, a mV generator Cl. 0.03 or
better, e.g. Model 6705.
1.
Test the feed voltages
±
15 V:
1.1
Connect points 17 and 21 on the voltage amplification board
2302/401 (next to the switch board) respectively to point 6
on the connector strip.
1.2
Connect the 2 soldering eyes located at the front between
the electrolytic capacitors 220/40 on the current generation
board to points 5/6/7 on the connector strip (applies as a
reference point for all voltage ratings on the current generation
board).
2.
Test the voltage on reference diode D 1 (current generation board).
Setpoint value of 6.2 V
±
5 %, but stable on 10 ppm. A sticker indicates
the setpoint value.
3.
The voltage at the output of V 1 must be twice the D 1 voltage (soldering eye
eye at R 3).
4.
Set the "Compensation" switch to OFF.
The output of V 2 (soldering eye above V 2) must indicate - 10 V
±
0.05 % if
P 1 is correctly connected/see item 13).
5.
The voltage at the emitter of T 1 (soldering eye next to P 4) must be below 4, but
positive.
6.
With the U terminals short-circuited, set the zero display of the device over the
smallest range using the lockable potentiometer on the front panel once V 5 has
warmed up (10 min.). The deviation must be less than
±
1 in all ranges. If not, see
item 9.
Test and offset instructions
Test and offset
instructions
