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Calculated Values at 5V:
Vout @0%=0.868 @75.3%=3.050 Vout = Vsupply * (0.1736 to 0.7533)
NaCl solution is 75.3%, the measured relative humidity is
MgCl
solution is 32.8%, the measured relative humidity is
2
LiCl solution is 11.3%, the measured relative humidity using is
Dry nitrogen solution is 0%, the measured relative humidity is
The HV test determines the optimum high-voltage setting for the PMT.
This test requires access to the High voltage module and the front of the Main Electronics Circuit
Board.
Measurements of the apparent light intensity of the quartz-halogen (standard) lamp are taken
through slitmask positions 1 and 2 (dark count, and wavelength 1) for a range of high voltages.
Prior to starting the test, locate shorting plug J2 on the High Voltage Module.
Method:
1.
Turn off Brewer power
2.
On the High Voltage module change jumper J2 from Pins 2-3 to Pins 1-2, and restore Brewer
power.
3.
Enter the HV command, and at the prompts, enter the PMT number, the preamp
discriminator level, the minimum, maximum and incremental voltages for the test. For the
PMT serno. and voltage settings see the Final Test Record.
WARNING:
4.
The Standard Lamp is turned ON, FW#1 is put to Position 1, FW#2 to Position 0, the Iris is
opened, and the zenith prism turned to the lamp housing.
5.
Following a 5 minute lamp warmup, the test runs, and data is written to the DJJJYY.nnn file
and to a HVJJJYY.nnn file.
Table F-2
: Typical photomultiplier response output
Photomultiplier S/N 10256
Control voltage
750
761
771
782
792
803
813
824
834
845
855
98
Radiometric response for 0 to 100%RH:
A photomultiplier, which is subjected to a too high voltage, may lead to
irreversible damage of the PMT and/or can decrease its lifetime.
The maximum allowable voltage is PMT specific. It is therefore recommended
not to exceed the voltages for your PMT as mentioned in the Final Test
Record.
Preamp voltage level:10
Dark Count
9
4
4
5
6
3
2
3
4
4
8
MKIV OPERATOR'S MANUAL
APPENDIX F FACTORY TESTS
%
%
Wavelength 1
10
10
15
25
49
79
238
648
1814
4466
9244
%
%
Ratio
Actual voltage
3
747.2
5
757.3
8
769.3
11
781.3
20
791.3
46
803.4
168
813.4
374
825.4
907
837.4
2233
847.5
3268
857.5
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