Teledyne 300 10.6.2Troubleshooting temperature problems, Low Flow, High Flow, Sample Temperature

Low Flow:

1.Check for leaks as described in Section 11.2. Repair and re-check.

2.Check for dirty sample filter or dirty orifice filter(s).

3.Check for partially plugged pneumatic lines, orifices, or valves.

High Flow:

1.The most common cause of high flow is a leak around an orifice. To correct, remove the orifice as described in Section 11.5, replace O-rings, and re-assemble.

10.6.2Troubleshooting temperature problems

The Model 300 has been designed to operate at ambient temperatures between 5oC and

40oC. As a first step in troubleshooting temperature problems, confirm the ambient temperature is within this range and that the air inlet slots on the sides of the cover and the fan exhaust on the rear panel are not obstructed.

The instrument monitors four temperatures:

•Sample Temperature

•Inside Chassis Temperature

•Optical Bench Temperature

•Gas Filter Wheel Temperature

and controls the temperatures of two components by heating:

•Optical Bench

•Gas Filter Wheel

If any of the temperature readings appear to be incorrect, check for proper thermistor operation by measuring the resistance of the thermistor(s). This resistance should be in the range of 7.6K ohms to 95 ohms. If it is not, the thermistor is defective and should be replaced. Points for measuring thermistor resistance are as follows:

Sample Temperature:

Unplug the connector at Motherboard J2 and measure across the leads.

Optical Bench Temperature:

Unplug the connector at Motherboard J4 and measure across the leads.

Gas Filter Wheel Temperature:

Unplug the connector at Motherboard J5 and measure across the leads.

Chassis Temperature:

Turn the analyzer off and remove the DC Power Supply Board. Measure across Motherboard J21 pins A30 and C30.

P/N 02163G1 Teledyne API Model 300 CO Analyzer Instruction Manual - Page 91