Metrohm 791 VA Detector - Manual (Page 43)

4.4 Instrument test with the dummy cell
791 VA Detector
37
3 Set selector 20 on the rear panel to –.
4 Set selector 21 on the rear panel to 0 … 1 V.
0...10 mV
0...1 V
5 Set commutator 3 "meas" to "on" position
(depressed position).
meas
6 Set potentiometer 9 I
comp
abs. to 0.
0.02 nA
Icomp
7 Bring recorder of voltmeter to 0 using potenti-
ometer 10 I
comp
rel..
Icomp
. I 0.01
8 If potentiometer 10 I
comp
rel. is now moved
counterclockwise by 100 divisions (= 1 turn)
then this should correspond to 1000 mV on the
recording instrument or voltmeter.
Icomp
. I 0.01
9 If potentiometer 9 I
comp
abs. is now moved
clockwise by 100 divisions (= 1 turn) then this
should correspond to the following values on
the recording instrument or voltmeter:
direct: +20 mV
× 5 button 5 depressed: +100 mV
× 50 button 6 depressed: +1000 mV
0.02 nA
Icomp
10 Set commutator 7 (+) to "on" position
(depressed position).
+
11 Similarly check the functioning of potentiometer
10 I
comp
rel. according to items 7 … 9.
Icomp
. I 0.01