Fluke Biomedical 942A-200L-M4 - Manual (Page 5)

General Information
General Description
1
1-1
Section 1
General Information
1.1 General Description
The Victoreen® Model 942A-200L-M4 or 942A-200L-M5 Universal Digital Ratemeters (UDR), when
connected to a beta or gamma sensitive scintillation detector, comprises a monitoring system which
operates in the range of 10 to 10
7 counts per minute (CPM). The UDR provides display, control, and
enunciator functions for the monitoring system.
Standard features for the 942A-200L-M4 and 942A-200L-M5 instrument include a five-digit display of the
CPM value and a multicolored bargraph indicator that covers the entire range of the UDR. The bargraph
will change color in the event of an alarm condition. Front panel alarm indicators and rear panel output
relays for alarm annunciation are also included. Front panel push-buttons are provided to display alarm
limit set points and high voltage value, for alarm acknowledgment, activation of a check source function
and activation of a trip test function. In addition, the 942A-200L-M4 includes a Model 942-200-90-M1
Single Channel Analyzer (SCA) option board, a front panel mounted SCA or Gross mode select switch
and a Model 942-200-95-M1 Dual Analog Output option board that provides additional 0-10 mV and 0-5
VDC analog outputs. The Model 942A-200L-M4 and 942A-200L-M5 are designed to be used with the
Model 943-25TL or 943-36L series scintillation detectors and a Model 844-211L series Junction Box to
provide an interface for a light emitting diode (LED) check source. The 942A-200L-M4 and 942A-200L-
M5 are internally wired to provide a +15v DC signal to operate the LED pulse circuit board mounted in the
844-211L series Junction Box. The +15v DC signal is available on rear panel connector P2. Refer to
Figures 1-1 and 1-2 for a general view of the UDR front panel.
The Model 942A-200L-M4 UDR is equipped with the following modifications:
- Model 942-200-95-M1 Analog output option board, with 0-10 mV and 0-5 VDC analog outputs
- Model 942-200-90-M1 Single Channel Analyzer Option Board with front panel mounted SCA/ Gross
Counting Mode select switch
- Front panel mounted trip test switch to verify display, bargraph, front panel LEDS and alarm relay
operation
- LED check source option: When the check source pushbutton is depressed, a +15 V dc signal is
sent to energize the pulser board in the 844-211L Junction Box. The pulser board then energizes a
LED in the detector to provide a check of the photomultiplier tube, preamplifier, counting circuits
and UDR.
The Model 942A-200L-M5 UDR is equipped with the following modifications:
- Front panel mounted trip test switch to verify display, bargraph, front panel LEDS and alarm relay
operation
- LED check source option: When the check source pushbutton is depressed, a +15 V dc signal is
sent to energize the pulser board in the 844-211L Junction Box. The pulser board then energizes a
LED in the detector to provide a check of the photomultiplier tube, preamplifier, counting circuits
and UDR.
NOTE
The Electrical Loop Drawings S174014D-102,
S174014E1003, S27860A-102 and S321299A-104,
provided in Appendix B, are intended to provide specific
project information on the UDR.