Teledyne 200AU instruction manual Test Functions, Test Function Factory Set-Up Comment

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

Table 9-1: Test Functions

Test Function	Factory Set-Up	Comment
RANGE	500 PPB	This is the Range of the instrument. In standard configuration all 3
		outputs have the same range.
		Independent range option allows different ranges for each output.
		When enabled, there will be 3 range values displayed.
		Auto range option allows 2 different ranges for all outputs, and
		will automatically switch to the other range dynamically as
		concentration values require. The TEST values will show the
		range the instrument is currently operating in, and will
		dynamically display the alternate range as the range changes
		occur.
STABIL	Check value in	The instrument stability is the Std. Deviation of the last 50 min of
	Final Test Values	NOx conc data. It is computed for the NOx channel only. The noise
	Table 2-1	value only becomes meaningful if sampling a constant
		concentration for more than 50 minutes. The noise value should be
		compared to the value observed in the factory check-out.
		Faults that cause high noise values are:
		1. Gas leaks
		2. Light leak
		3. Faulty HVPS
		4. Defective Preamp board
		5. Outgassing Moly converter
		6. PMT recently exposed to room light
		7. Dirty/contaminated reaction cell
		8. Mis-calibrated (slope - offset outside of limits)
SAMPLE FLW	1000 cc/min	This is the instrument flow. It is computed using the up stream and
	± 100	down stream pressures across the sample flow orifice. This
		method can give a false flow indication if the orifice is plugged
		and the sample pump is creating a pressure drop. It should be
		taken into account when diagnosing instrument faults.
		- A rapid method of determining if the orifice is plugged is to
		disconnect the sample and ozone tubes from the reaction cell, then
		briefly put your finger over the fittings on the cell. You should
		feel the vacuum build up. Also note the difference between the
		high sample flow and the low ozone flow rate.
		- Another reliable method is to attach a rotameter or soap bubble
		flowmeter to the fittings to measure the flows.
		Flow rate will change ± a few cc/min due to changes in ambient
		air pressure such as cycling of air conditioning, or passing weather
		fronts. Changing altitude changes the ambient air pressure and
		therefore the sample flowrate. This effect is about 15-20 cc/min
		per 1000 feet of altitude change. If required, the output of the
		instrument can be compensated for pressure. See Section 5.3.9,
		Table 9-5.

(table continued)

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