Teledyne 200AU instruction manual Prereact

Teledyne API Model 200AU NOX Analyzer Instruction Manual, 02293, Rev. F

Table 9-1: Test Functions (Continued)

Test Function	Factory Set-Up	Comment
PREREACT	Check value in	PREREACT is the current value of the Pre-reactor circuit reading.
	Final Test Values	The number typically should be
	Table 2-1	0 mV -15/+35 if the instrument is sampling zero air. When the
		M200AU is in SAMPLE mode readings may be higher if sample
		gas contains hydrocarbons. If a problem is suspected, check the
		Pre-reactor and NO/NOx valves for cross port leaks. Use
		Diagnostic mode to manually switch the valves while checking for
		leaks and correct operation.
HVPS	450 – 900 VDC	This represents the scaled-up HVPS programming voltage to the
		HVPS. The design of the HVPS precludes taking a single reading
		that indicates the health of the supply. Refer to the HVPS
		Troubleshooting Section 9.3.8.5 for a procedure for testing the
		HVPS. This TEST function is used primarily to set the HVPS
		voltage value. A value not in the 450 to 900 volt range indicates
		problems with the HVPS supply.
DCPS	2500 ± 200 mV	DCPS is a composite of the +5 and ± 15 VDC supplies. It has
		been arbitrarily set at 2500 ± 200 mV. If it is not in this range one
		of the voltages in the supply is not working. Check the procedures
		for diagnosing the Power Supply Module in Section 9.3.5.
RCELL TEMP	40 ± 1° C	The reaction cell temperature is controlled to 40° C ± 1° C by the
		computer. It should only read other values when the instrument is
		warming up. If the value is outside the acceptable range, go to the
		procedure for diagnosing the Reaction cell temp supply in Section
		9.3.8.2. The alarm limits are less than 35° C and greater than
		45° C.
BOX TEMP	8 - 48° C	The Box Temp is read from a thermistor on the Status/Temp
		board. It should usually read about 5° C above room temp. The
		M200AU is designed to operate from 20 to 30° C ambient.
		Therefore the box temperature should be in the range of about 10
		to 50° C. Temperatures outside this range will cause premature
		failures of components, and poor data quality. Warning limits are
		< 8° C and > 48° C.
PMT TEMP	-5 ± 1° C	The PMT detector is very temperature sensitive. The PMT
		temperature should always be –5°C, except at power-up.
		Temperatures more than ± 1° C from the set point indicate
		problems with the cooler circuit. See Section 9.3.8.4 for PMT
		cooler diagnostic and troubleshooting. Warning limits are < -8°C
		and > -2°C.
BLOCK TEMP	40 ± 2o C	Reports the temperature of the sample flow and ozone flow
		control orifices. Variations in these temperatures will cause span
		concentration drift.

(table continued)

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