Filter
Top Products
Troubleshooting and Service Teledyne API – Model T700 Dynamic Dilution Calibrator
246
TEST FUNCTION DIAGNOSTIC RELEVANCE AND CAUSES OF FAULT CONDITIONS.
PH STEMP
2
The temperature of the gas in the photometer’s sample chamber is used to calculate the
concentration of O
3
in the gas stream. Incorrect sample temperature can cause inaccurate
readings.
Possible causes of faults are:
- Bad bench lamp heater
- Failed sample temperature sensor
- Failed relay controlling the bench heater
- Failed Relay PCA
- I
2
C Bus malfunction
- Hot Lamp
PH SLOPE
2
Values outside range indicate:
Contamination of the Zero Air or Span Gas supply.
Instrument is miss-calibrated.
Blocked Gas Flow.
Faulty Sample Pressure Sensor or circuitry.
Bad/incorrect Span Gas concentration.
PH OFFST
2
Values outside range indicate:
Contamination of the Zero Air supply.
TIME
Time of Day clock is too fast or slow.
To adjust see Section 4.5.
Battery in cl
ock chip on CPU board may be dead.
1
Only appears when the optional O
3
generator is installed.
2
Only appears when the optional O
3
photometer is installed
9.1.3. USING THE DIAGNOSTIC SIGNAL I/O FUNCTION
The Signal I/O parameters found under the DIAG Menu combined with a thorough
understanding of the instrument’s Theory of Operation (found in Section 10) are useful
for troubleshooting in th
ree ways:
The technician can view the raw, unprocessed signal level of the calibrator’s critical
inputs and outputs.
Many of the components and functions that are normally under algorithmic control
of the CPU can be manually exercised.
The technician can directly control the signal level Analog and Digital Output
signals.
This allows the technician to observe systematically the effect of directly controlling
these signals on the operation of the calibrator. Figure 9-1 is an example of how to use
the Signal I/O menu to view the raw voltage of an input signal o
r to control the state of
an output voltage or control signal. The specific parameter will vary depending on the
situation.
06873B DCN6388