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Model 400E Ozone Analyzer
Instruction Manual
MAINTENANCE SCHEDULE & PROCEDURES
P/N 04316 Rev: B
207
9.2.
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 04314. Table 9-2 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 9-2: Predictive Uses for Test Functions
Function
Mode
Behavior
Interpretation
Stability
Zero Cal
Increasing
§
Pneumatic leaks – instrument &
sample system
§
Malfunctioning UV lamp (Bench)
O3 Ref
Sample
Decreasing
§
UV lamp ageing
§
Mercury contamination
O3 Drive
CALS
Increasing
§
Ageing IZS UV lamp (only if
reference detector option is
installed)
Increasing > 1”
§
Pneumatic Leak between sample
inlet and optical bench
Pres
Sample
Decreasing > 1”
§
Dirty particulate filter
§
Pneumatic obstruction between
sample inlet and optical bench
§
Obstruction in sampling manifold
Samp Fl
Sample
Decreasing
§
Pump diaphragm deteriorating
§
Sample flow orifice
plugged/obstructed
§
Pneumatic obstruction between
sample inlet and optical bench
§
Obstruction in sampling manifold
Increasing
§
Pneumatics becoming
contaminated/dirty
§
Dirty particulate filter
§
Pneumatic leaks – instrument &
sample system
Slope
Span Cal
Decreasing
§
Contaminated calibration gas
Increasing
§
Obstructed/leaking Meas/Ref Valve
§
Pneumatic leaks – instrument &
sample system
Offset
Zero Cal
Decreasing
§
Contaminated zero calibration gas
§
Obstructed Meas/Ref Valve
§
Pneumatic leaks – instrument &
sample system