Fluke Biomedical 943-35 - Manual (Page 11)

Operation
Installation
2
2-1
Section 2
Operation
2.1 Installation
Ensure all power is removed prior to installing the
943 Series Detector.
If the detector is used in a process monitoring
system, refer to the applicable system manual for
all applicable system drawings and special
mounting instructions. Electrical and mechanical
drawings for the detector are provided in Appendix
A.
The detector is designed for use in a number of process monitoring configurations in a number of
Victoreen sampler assemblies. Installation is system dependent. Installation will generally consist of
mounting the detector in the desired configuration, performing electrical interconnections, and performing
any system testing which may be required. Refer to the applicable system manual for installation
instructions for the sampler assembly supplied.
1. Install the detector into the desired mounting location (refer to the Appendix A, the readout manual,
or the system manual for specific mounting details).
2. Set the high voltage potentiometer to its lowest setting (not required if the detector and readout
were factory calibrated prior to shipment).
3. Connect the appropriate cables between the detector and the readout.
Do not exceed 1200 VDC @ 500 μA to the detector
under any circumstances. Failure to comply will
result in damage to the detector.
4. If the detector is part of a radiation monitoring system, turn on channel power and verify the high
voltage is set to the value indicated on the factory calibration sheet. If the detector is a replacement
part, turn on channel power and slowly increase the high voltage until a count rate of approximately
3000 CPM is achieve (this count rate assumes that the detector is in open air and that the
discriminator threshold is set at 0.2 VDC in the readout). If the detector is placed within a lead
shield, the high voltage should be increased until a count rate of approximately 100 CPM is
achieved.
5. Allow a one-hour warm-up before proceeding to calibration.
CAUTION
NOTE
CAUTION