Teledyne t320, t320u 11.2. PREDICTING FAILURES USING THE TEST FUNCTIONS

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11.2. 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 11-3 can be used as a basis for taking action
as these values change with time. The internal data acquisition system (DAS) is a
convenient way to record and track these changes. Use APICOM to download and
review this data from a remote location.
Table 11-3: Predictive uses for Test Functions
FUNCTION CONDITION BEHAVIOR INTERPRETATION
STABILITY Zero Cal Increasing  Pneumatic Leaks – instrument & sample system
 Detector deteriorating
CO MEAS Zero Cal Decreasing
 Source Aging
 Detector deteriorating
 Optics getting dirty or contaminated
Increasing
 Source Aging
 Detector deteriorating
 Contaminated zero gas (H2O)
Zero Cal
Decreasing
 Source Aging
 Detector deteriorating
 GFC Wheel Leaking
 Pneumatic Leaks
 Contaminated zero gas (CO)
Increasing
 Source Aging
 Pneumatic Leaks – instrument & sample system
 Calibration system deteriorating
 GFC Wheel Leaking
MR RATIO
Span Cal
Decreasing  Source Aging
 Calibration system deteriorating
Increasing > 1”  Pneumatic Leak between sample inlet and Sample Cell
 Change in sampling manifold
PRES Sample
Decreasing > 1”
 Dirty particulate filter
 Pneumatic obstruction between sample inlet and
Sample Cell
 Obstruction in sampling manifold
PHT DRIVE
Any, but with
Bench Temp at
48°C
Increasing
 Mechanical Connection between IR-Detector and
Sample Cell deteriorating
 IR-Photodetector deteriorating
Increasing  See MR Ratio - Zero Cal Decreasing above
OFFSET Zero Cal
Decreasing  See MR Ratio - Zero Cal Increasing above
Increasing  See MR Ratio - Span Cal Decreasing above
SLOPE Span Cal
Decreasing  See MR Ratio – Span Cal Increasing above
06864B DCN6314