Fluke Biomedical 956A-201-M2 - Manual (Page 19)

2-1
Section 2
OPERATION
2.1 INSTALLATION
Installation consists of selecting suitable mounting sites for the detector and ratemeter, mounting the
equipment, making the required electrical connections, and entering the desired setpoints. Installation
drawings are provided in Appendix B of this manual.
Remove all power prior to installing the UDR or detector.
2.2 G-M DETECTOR MOUNTING
The 897A Series G-M detectors can be mounted to any suitable structure e.g. a wall or post, using the
mounting bracket (P/N 843-6-26) included with the detector. The maximum distance between the
detector and ratemeter is 2000 feet (610 meters). The detector should be mounted above normal head
height with the detector connector facing away from the area being monitored. For additional information
refer to the applicable engineering drawings, provided in Appendix B, for detector mounting dimensions.
To protect the monitor from EMI/RFI transients, the detector must be earth grounded through its wall-
mounting bracket.
2.3 G-M DETECTOR SETUP
The low voltage power supply input for the preamplifier is jumper selectable. This allows the use of either
a +10 Vdc or +15 Vdc supply for detector power. If the detector is used with a 956A-201 Series UDR, the
standard +15 Vdc position is used. If the detector is used in an analog radiation monitoring system, the
+10 Vdc position is used. Jumper configurations are listed in Table 2-1.
Table 2-1
Input Voltage Jumper Position
Jumper Position Input Voltage
J3 AB + 15 Vdc (factory set), digital readout
J3 BC + 10 Vdc, analog readout
The G-M tube output pulse is conditioned with a divide by 2 pulse shaping circuit to transmit a square
wave from the detector. The conditioning also permits use of the detector with analog readouts, using a
diode pump counting circuit. For use with fast rise time scalers, a jumper is provided to output the
detector pulse directly. Jumper configurations are listed in Table 2-2.
CAUTION