Fluke Biomedical 943-27 Detector - Manual (Page 13)

Operation
Installation
3
3-3
CAUTION
Remove all power prior to connecting field wiring.
Electrical Interface
Electrical connections from the detector include a high voltage and a signal coaxial cable, with pre-
terminated connectors. The connectors are designed for termination within the associated preamplifier.
The detector high voltage and signal cables enter the preamplifier through “Seal Grip” type penetrations
on the enclosure body. The “Seal Grips” contain a rubber gland that is intended to grip the coaxial cables
to prevent moisture entry into the enclosure. The “Seal Grips” are an integral part of the detector cables.
The “Seal Grip” enclosure nut is removed from the fitting. The insulating washer stays with the fitting.
The detector signal and high voltage cables, with connectors and “Seal Grip” fitting nuts are then inserted
into the holes preamplifier enclosure. The “Seal Grip: end fittings are then re-installed securely against
the wall of the enclosure.
The detector Signal (BNC) and High Voltage (SHV) cables are then terminated on the bulkhead
connectors located on the enclosure inner panel.
NOTE
The electrometer circuitry in the preamplifier is highly sensitive to
moisture and physical damage. Use extreme care when the preamplifier
case is opened as the high impedance electrometer circuitry is easily
damaged. Do not leave the preamplifier enclosure in the open position
for any extended period of time.
3.2 Set-up
Once the detector is installed and electrically connected to the preamplifier, the detector must be
calibrated. This includes exposing the detector to a series of standard radioactive sources and adjusting
the high voltage supplied by the readout device to obtain the same output current (adjusted for
radioactive decay) that was obtained during the factory calibration. This data is provided on the
Calibration Data sheet provided with the detector. To place the system in operation, the following steps
should be performed:
NOTE
Ensure you have read and fully understand
Section 1, 2 and 3 prior to continuing.
1. Adjust the High Voltage. Refer to the applicable preamplifier and readout/controller device manual
prior to powering up the controller and adjusting the high voltage.