Kipp&Zonen Brewer MkIII - Manual (Page 18)

MKIII SERVICE MANUAL 13
to the actual high voltage divided by 409. There may be a variation of a volt or two of the high
voltage, but the voltage at test point should be very close to the final test record value. If it is
significantly different, the high voltage circuit may have failed. This will require a skilled technician
for repair or KIPP & ZONEN should be contacted.
8. Check Light Detection System
If the high voltage appears to be normal from the test point reading, then there is a possibility that
something has failed in the Light Detection System, reference Section 4.7.
4.3 STANDARD LAMP CIRCUIT
The standard lamp current regulator is similar to the Mercury lamp circuit except the resistance
wire is chosen to regulate the supply current with less variation than the mercury lamp. The circuit
maintains the operating current within 3 milliamps over a range of -20 to + 40 degrees C, and is
even more stable in the operating range of 10 to 30 degrees.
4.4 STANDARD LAMP FAILURE
The quartz-halogen (Standard) lamp is the lamp most frequently used in self diagnostics of the
Brewer. With it, calibration can be monitored, and correct operation of many systems can be
inferred.
The software for the standard lamp tests has been designed to give an error message in the event
of a failure. The message is "Lamp not on test terminated". The message may be somewhat
misleading in that there are many conditions which can make it appear that the Lamp is not on.
These conditions include PMT performance, filterwheel positioning, Zenith prism position, photon
counting electronics, and the I/O electronics used to turn the lamp on and off.
4.5 TROUBLE-SHOOTING STANDARD LAMP TEST FAILURE
Error message, "Lamp not on test terminated".
1. Check if Lamp is Burned Out
Retry the test and if the lamp is on, it will be seen through the viewing ports if the Filter Wheels, iris,
and the Zenith Prism have moved into the proper position. Perform an AP (A/D voltages printout)
test and compare results with previous tests, paying particular attention to standard lamp current
and voltage. The current, channel 14, will be approximately zero and the voltage, channel 15, will
exceed 14 volts if the lamp is unplugged or burnt out.
2. Attempt HG Test
If the test continues to fail, a mercury lamp test should be attempted. If the mercury lamp test
operates correctly, then the Light Detection System is probably operating correctly. If so, a
mercury lamp calibration should be done and the Standard Lamp test should be repeated.
4 OPERATING TEST FAILURES