Detcon DM-700 - Manual (Page 36)

Model DM-700
DM-700 Instruction Manual Rev. 4.0 Page 32 of 48
6. Troubleshooting Guide
Refer to the list of Failsafe Diagnostic features listed in Section 3.6.2 for additional reference in
troubleshooting activities. Listed below are some typical trouble conditions and their probable cause and
resolution path.
ITM
Bottom View
Display
Window
Plug in Sensor
Bottom view
Locking
Setscrew
Locking
Setscrew
Place programming
connector towards
back away from
display window
PLUG-IN O
ALIGN AR
WITH LED
ntents on skin
MODEL
DM-700
detcon inc.
H 2 S Sensor
detcon inc.
Figure 16 Sensor Cell and ITM Mating
Under-Range Fault
Probable Cause: Sensor Baseline drifted lower, Interference gasses.
 Repeat AutoZero. Use Zero Air or N
2
source.
 Allow more time for zero stabilization if this is a biased sensor type.
 Execute successful AutoSpan and verify adequate Sensor Life.
 Check Raw counts in View Sensor Status. Should be close to 33,000 counts when normal.
 Replace plug-in sensor if fault continues.
Missing Sensor Fault
Probable Cause: Sensor is Missing, Failed Plug-in Sensor Electronics, or ITM I.S. Barrier Failure.
 Make sure plug-in sensor is plugged in properly with correct orientation.
 Swap plug-in sensor into another ITM to determine if plug-in sensor problem or ITM problem
 Replace the plug-in sensor if proven faulty
 Replace the ITM if proven faulty
AutoSpan Calibration Faults – (Range, Stability and Clearing)
To clear any AutoSpan Calibration fault, the AutoSpan process must be completed successfully (Section3.4).
Range Fault
Probable Causes: Failed Sensor, Cal Gas not applied or not applied at appropriate time, problems w/ cal gas
and delivery.