Fluke Biomedical 943-25 - Manual (Page 18)

Victoreen 943-25, 943-26
Operators Manual
4-6
3. Turn on channel power.
4. Using a pulse generator, inject negative pulses of -0.50 V amplitude, one microsecond pulse
duration, at a frequency of 1 kHz to the node of R13 and C6 (+) and gnd (-).
5. Output pulses should be -1.6 V ± 20% amplitude. If pulses are not present, check Z1 and
associated circuitry.
If the preamplifier and dynode tests are positive, the detector malfunction is probably in the
photomultiplier tube. Remove all power, replace the photomultiplier tube and reassemble the detector
according to the procedure in Section 4.1.2.
4.8 Replacement Parts
Drawing Number Description
943-25 Beta Scintillation Detector, Mylar End Window,
943-26 1:1 Response Ratio
943-25A Beta Scintillation Detector, Mylar End Window,
943-26A 10:1 Response Ratio
943-25B Beta Scintillation Detector, Mylar End Window,
943-26B 100:1 Response Ratio
943-25T Beta Scintillation Detector, Titanium End Window,
943-26T 1:1 Response Ratio
943-25TA Beta Scintillation Detector, Titanium End Window,
943-26TB 10:1 Response Ratio
943-25TB Beta Scintillation Detector, Titanium End Window,
943-26TB 100:1 Response Ratio
Refer to the individual assembly drawings for a
breakdown of individual components.
NOTE