Teledyne 9110T Fault Diagnosis with Test Functions, OUT of Range reading, Pressure

Model 9110T NOx Analyzer Troubleshooting & Service

12.1.2. FAULT DIAGNOSIS WITH TEST FUNCTIONS

In addition to being useful as predictive diagnostic tools, the test functions viewable from the analyzers front panel can be used to isolate and identify many operational problems when combined with a thorough understanding of the analyzer’s principles of operation (see Section 13).

The acceptable ranges for these test functions are listed in the “Nominal Range” column of the analyzer Final Test and Validation Data Sheet (P/N 04490) shipped with the instrument. Values outside these acceptable ranges indicate a failure of one or more of the analyzer’s subsystems. Functions whose values are still within acceptable ranges but have significantly changed from the measurement recorded on the factory data sheet may also indicate a failure.

A worksheet has been provided in Appendix C to assist in recording the value of these test functions.

Note	A value of “XXXX” displayed for any of these TEST functions indicates an
	OUT OF RANGE reading.

Note	Sample Pressure measurements are represented in terms of ABSOLUTE
	pressure because this is the least ambiguous method reporting gas
	pressure.
	Absolute atmospheric pressure is about 29.92 in-Hg-A at sea level. It
	decreases about 1 in-Hg per 1000 ft gain in altitude. A variety of factors
	such as air conditioning systems, passing storms, and air temperature,
	can also cause changes in the absolute atmospheric pressure.

TEST FUNCTION

NOX STB

SAMP FlW

OZONE FL

PMT

NORM PMT

AZERO

HVPS

RCELL TEMP

BOX TEMP

PMT TEMP

IZS TEMP (option)

MOLY TEMP

RCEL (pressure)

SAMP (pressure)

NOX SLOPE

Table 12-2: Test Functions - Indicated Failures

INDICATED FAILURE(S) Unstable concentrations; leaks

Leaks; clogged critical flow orifice Leaks; clogged critical flow orifice Calibration off; HVPS problem; no flow (leaks) Auto Zero too high

Leaks; malfunctioning NO, NOx or Auto Zero valve; O3 air filter cartridge exhausted Calibration off; preamp board circuit problems

Malfunctioning heater; relay board communication (I2C bus); relay burnt out Environment out of temperature operating range; broken thermistor

TEC cooling circuit broken; relay board communication (I2C bus); 12 V power supply Malfunctioning heater; relay board communication (I2C bus); relay burnt out

Malfunctioning heater; disconnected or broken thermocouple; relay board communication (I2C bus); relay burnt out; incorrect AC voltage configuration

Leak; malfunctioning valve; malfunctioning pump; clogged flow orifices

Leak; malfunctioning valve; malfunctioning pump; clogged flow orifices; sample inlet overpressure

HVPS out of range; low-level (hardware) calibration needs adjustment; span gas

Teledyne Analytical Instruments 266