Kipp&Zonen Brewer MkIII - Manual (Page 99)

MKIII OPERATOR'S MANUAL 96
Method:
Send the PDHPHG command sequence to the Brewer, wait for the tests to finish.
The SH command is entered to start the slitmask-motor timing test. The program prompts for the
minimum, maximum, and increment for trial values of the delay constant. Typical values are a
minimum value of 2, a maximum of 30, and an increment of 2. After a five-minute lamp warm-up
period, the program performs a series of intensity measurements for each trial value of the timing
constant, then prints the measurements in tabular format. The following information is contained in
the printout:
DELAY CAL DARK WAVELENGT
H 1
2 838674 162992 52984
4 1737756 32765 91539
6 1761988 15366 92076
8 1738607 10860 92448
10 1737768 7557 92828
12 1738031 480 93450
14 1737408 39 93100
16 1738864 37 93422
18 1738388 44 93318
20 1737191 28 93579
22 1738692 36 93580
24 1742088 40 93713
26 1737650 34 93666
28 1737937 32 93596
Dark Count versus Slitmask Delay should be plotted and compared to the plot shown in the Final
Test Record. The optimum slitmask delay time is that which minimizes the dark count - typically
this delay constant would lie within the range 10 to 16. For the table above the optimum delay
constant is 14.
The new delay constant should agree with the final test record value within an acceptance
tolerance of ±5. If the new constant is significantly different from the final test value then the factory
should be contacted before changing the configuration in the firmware since a complete instrument
re-calibration may be necessary.
HV: HIGH VOLTAGE TEST
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.