Teledyne GFC 7001E Predicting Failures Using the Test Functions, Function Condition Behavior

Maintenance Model GFC7001E Carbon Dioxide Analyzer

12.2.PREDICTING FAILURES USING THE TEST FUNCTIONS

The Test Functions can be used to predict failures by looking at how their values change over time. Initially it may be useful to compare the state of these Test Functions to the values recorded on the printed record of the final calibration performed on your instrument at the factory, P/N 04307. Table 12-3 can be used as a basis for taking action as these values change with time. The internal data acquisition system (iDAS) is a convenient way to record and track these changes. Use APICOM to download and review this data from a remote location.

Table 12-3: Predictive uses for Test Functions

FUNCTION	CONDITION	BEHAVIOR
STABILITY	Zero Cal	Increasing
CO MEAS	Zero Cal	Decreasing
		Increasing
	Zero Cal
		Decreasing
MR RATIO
		Increasing
	Span Cal
		Decreasing
		Increasing > 1”
PRES	Sample
		Decreasing > 1”
PHT DRIVE	Any, but with
	Bench Temp at	Increasing
	48°C
OFFSET	Zero Cal	Increasing
		Decreasing
SLOPE	Span Cal	Increasing
		Decreasing

INTERPRETATION

Pneumatic Leaks – instrument & sample system

Detector deteriorating

Source Aging

Detector deteriorating

Optics getting dirty or contaminated

Source Aging

Detector deteriorating

Contaminated zero gas (H2O)

Source Aging

Detector deteriorating

GFC Wheel Leaking

Pneumatic Leaks

Contaminated zero gas (CO)

Source Aging

Pneumatic Leaks – instrument & sample system

Calibration system deteriorating

GFC Wheel Leaking

Source Aging

Calibration system deteriorating

Pneumatic Leak between sample inlet and Sample Cell

Change in sampling manifold

Dirty particulate filter

Pneumatic obstruction between sample inlet and Sample Cell

Obstruction in sampling manifold

Mechanical Connection between IR-Detector and Sample Cell deteriorating

IR-Photodetector deteriorating

See MR Ratio - Zero Cal Decreasing above

See MR Ratio - Zero Cal Increasing above

See MR Ratio - Span Cal Decreasing above

See MR Ratio – Span Cal Increasing above

Teledyne Analytical Instruments 263