Metrohm 791 VA Detector - Manual (Page 42)

4 Maintenance – Malfunctions
791 VA Detector
36
4 Set selector 20 on the rear panel to –.
5 Set selector 21 on the rear panel to 0 … 1 V.
0...10 mV
0...1 V
6 Set recorder sensitivity to 1000 mV.
7 Set commutator 3 "meas" to "on" position
(depressed position).
meas
8 Set potentiometer 9 I
comp
abs. to 0.
0.02 nA
Icomp
9 Bring recorder of voltmeter to 0 using potenti-
ometer 10 I
comp
rel..
Icomp
. I 0.01
10 Alter the settings of digital switch 11 U
pol
in
steps of 100 mV and 10 mV: The settings
shown on the digital switch should be repro-
duced on the recorder or voltmeter within a
tolerance of <12.5 mV and <1.25 mV respec-
tively.
1 4 0 +
11 Set digital switch 11 U
pol
to – and alter the
settings in steps of 100 mV and 10 mV: The
settings shown on the digital switch should be
reproduced on the recorder or voltmeter within
a tolerance of <12.5 mV and <1.25 mV respec-
tively.
2 5 0
4.4.3 Check of current compensation
1 Set digital switch 11 U
pol
to 0 mV.
0 0 0 +
2 Set adjusting knob 8 to 0.1 µ A.
4
5
1
10
50
1
5
0,1
0,5 100
10
0,5
0,1