Rosemount 755, Инструкция по эксплуатации

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M
ODEL
755 O
XYGEN
A
NALYZER
7-12
748183-H
Rosemount Analytical December 1997
This resistance should be approximately 89 ohms. If resistance was correct, and yet
the combined resistance was incorrect, heater HR1 may be open. To reach the leads
of HR1. remove the printed circuit board on the heater assembly. Resistance of HR1
should be approximately 21 ohms.
To check operation of the heater circuit, connect a voltmeter across R61 on the case
circuit board . Normally the voltage will be 4 VDC when cold, and will drop to
approximately 0.4 VDC at control temperature. Temperature sensor RT1 is mounted in
the detector with leads accessible at pins 10 and 11 of detector connector J12. The
sensor resistance, as measured at these pins, should be 1M ohms at 25
°
C and
approximately 149K ohms at operating temperature of 65
°
C.