Filter
Top Products
Troubleshooting and Service Teledyne API Model T360/T360M Operation Manual
244
8.4. OTHER PERFORMANCE PROBLEMS
Dynamic problems (i.e. problems which only manifest themselves when the
analyzer is monitoring sample gas) can be the most difficult and time consuming
to isolate and resolve. The following provides an itemized list of the most
common dynamic problems with recommended troubleshooting checks and
corrective actions.
8.4.1. Temperature Problems
Individual control loops are used to maintain the set point of the absorption
bench, filter wheel, and IR photo-detector temperatures. If any of these
temperatures are out of range or are poorly controlled, the T360 will perform
poorly.
8.4.1.1. BOX OR SAMPLE TEMPERATURE
Box Temperature
The box temperature sensor is mounted to the motherboard and cannot be
disconnected to check its resistance. Rather check the BOX TEMP signal using
the SIGNAL I/O function under the DIAG Menu (See Section 8.1.3). This
parame
ter will vary with ambient temperature, but at ~30
o
C (6-7° above room
temperature) the signal should be ~1450 mV.
Sample Temperature
The Sample Temperature should closely track the bench temperature. If it does
not, locate the sensor, which is located at the midpoint of the optical bench in a
brass fitting. Unplug the connector labeled “Sample”, and measure the resistance
of the thermistor; at room temperature (25°C) it should be ~30K Ohms, at
operating temperature, 48°C, it should be ~ 12K Ohms
8.4.1.2. BENCH TEMPERATURE
There are three possible failures that could cause the Bench temperature to be
incorrect.
WARNING:
HAZARDOUS VOLTAGES ARE PRESENT DURING THIS TEST
1. The heater mounted to the bottom of the Absorption bench is electrically
shorted or open. Check the resistance of the two heater elements by
measuring between pin 2 and 4 (~76 Ohms), and pin 3 and 4 (~330 Ohms),
of the white five-pin connector just below the sample temperature sensor on
the Bench (pin 1 is the pointed end).
2. Assuming that the I
2
C bus is working and that there is no other failure with
the relay board, the solid-state relay (K2) on the relay board may have failed.
07272B DCN6552