Fluke Biomedical 945A - Manual (Page 30)

CAUTION
Do not actuate the check source when the reading is above 1 R/h.
The radiation measurement is additive to the check source signal
resulting in improper values from the check source. This may
result in the UDR indicating a failure when the instrument is
operating correctly.
NOTE
The Check Source relay, though energized in the Check Source
Mode, Does not have an active function in the 945A Area Monitoring
System.
The bargraph operates normally during Check Source operation.
The analog outputs are set to zero ( i.e. 0 Vdc or 4 mA) during Check Source operation.
Maintenance Mode
The Maintenance Mode is designed to allow adjustments to be made on the electrometer board in the
preamplifier without tripping the FAIL alarm. Maintenance Mode is selected by setting SW3-3 on the 977
interface board, in the preamplifier, to the ON position.
The bargraph works the same as in Rate Mode. The units on the numeric digital display flash as long as
data is being received from the preamplifier. If communication with the preamplifier fails, the flashing
stops.
The FAIL alarm and all failure error codes except E0007 (communications failure) are inhibited. The
UDR analog outputs are active. The local preamplifier analog output may be checked at this time. SW3-
4 in the OFF position forces the output to zero; SW3-4 in the ON position forces the output to full (refer to
Table
4-3).
The HIGH, WARN, and RANGE alarms may be inhibited during Maintenance Mode by setting SW3-2 on
the 977 interface board to the OFF position. These alarms are enabled when SW3-2 is in the ON
position.
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