Chapter 8 | Troubleshooting
Introduction
This chapter provides troubleshooting information for the gas
monitor.
Diagnosing Common Problems
LED display does not
light up.
Input voltage is too
low
Electronics module
has failed
Check for presence of input
voltage.
Output outside
4-20 mA range
Unit in calibration
mode
Electronics module
has failed
Exit calibration mode.
Replace electronics module.
Output does not
change when gas
concentration
changes
Electronics module
has failed
Replace electronics module.
Sensor has failed
Electronics module
has failed
Replace sensor and calibrate.
Replace electronics module and
calibrate.
Reading drifts by 10
counts over a short
time period (in a
stable temperature
environment)
Sensor has failed
Electronics module
has failed
Replace sensor and calibrate.
Replace electronics module and
calibrate.
In calibration, LED
displays wrong value.
Sensor has failed
Electronics module
has failed
Replace sensor and calibrate.
Replace electronics module and
calibrate.
Reed Switch does not
work
Electronics module
has failed
Reed Switch is
damaged
Replace electronics module and
calibrate.
Replace the reed switch.
“P” appears on the
display
Open loop on a 4-20
mA channel
Place a 100-Ohm load resistor
from the mA output pin to