Detcon CX-DM - Manual (Page 31)

Model CX-DM
6. Troubleshooting Guide
If the ITM detects any functional errors the ITM will display the fault. If the sensor is experiencing a fault
condition a momentary swipe of the magnet will cause the ITM to scroll the fault condition(s) across the
display before the "
◄" or "►" prompt will appear.
The Display Error Codes are:
Auto Span Fault
Temperature Fault
Memory Fault
Processor Fault
Clearing Fault
Range Fault
Sensor Fault
Zero Fault
Sensor Fault 2
Some faults are self-explanatory, and if these faults occur and cannot be cleared the ITM should be replaced
first to see if the fault will clear. Other faults may need further investigation. Some of the sensor problems,
associated error codes, and resolutions are listed below.
6.1 Under-Range problems
Probable Cause: Sensor Baseline drifted lower, Interference gases,
• Perform Zero Calibration. Use Zero Air or N
2
source. (Section3.3.1 AutoZero)
• Allow more time for zero stabilization if this is a biased sensor type.
• If using Splashguard with Integral Cal Port, must use Calibration Wind Guard or air movement can
compromise span gas delivery.
• Execute successful Span Calibration. (Section 3.3.2 AutoSpan)
• Replace plug-in toxic sensor if error continues.
6.2 Stability problems
Probable Causes: Failed Sensor, empty or close to empty Cal Gas Cylinder, problems with cal gas
and delivery
• Check validity of span gas using pull tube or other means (check MFG date on cal gas cylinder).
• Use proper cal gas regulators and tubing for highly corrosive gases
• If using Splashguard with Integral Cal Port, must use Calibration Wind Guard or air movement can
compromise span gas delivery.
• Check for obstructions affecting cal gas hitting sensor face (including being wet, blocked, or
corroded). H2S sensors assemblies use CX-DM Series Splashguard Adapter Assembly with integral
filter. Clean or replace if necessary.
• Replace the plug-in toxic sensor.
6.3 Clearing problem
Probable Causes: Failed Sensor, Cal Gas not removed at appropriate time, problems with cal gas and
delivery, Background of Target Gas.
• The sensor must recover to < 5% of range in < 5 min after Span calibration is complete
• Use bottled air (zero air or N
2
) if there is a known continuous background level.
• Check validity of span gas using pull tube or other means (check MFG date on cal gas cylinder).
• Use proper cal gas regulators and tubing for highly corrosive gases
CX-DM Instruction Manual Rev. 1.3 Page 27 of 40