AQ EXPERT Instruction & Operations Manual
Version 1.13
Page 54 of 63
CHAPTER 13
BASIC TROUBLESHOOTING
ZERO ERRORS
Channel
Possible Causes
Resolution
(Electrochemical
sensors)
CO
NO
NO
2
SO
2
H
2
S
CH
2
O
O
2
O
3
Sensor has been recently
exposed to gas and has not
yet returned to zero.
Purge for 10 minutes with fresh air,
monitor sensor voltage, and re-zero.
Insufficient Warm Up
Allow the sensors to warm up after
10 minutes
Incorrect ZERO calibration
Repeat ZERO cal in fresh air or with
ZERO AIR cylinder
Pump Failed
Check pump flow, if pump failed
replace
Battery was dead, sensor
has destabilized.
Charge battery, wait up to 24 hours
for sensors to stabilize, and re-zero.
Sensor cell life has expired.
Call E INSTRUMENTS for
replacement.
(PID sensors)
VOC
Sensor has been recently
exposed to gas and has not
yet returned to zero.
Purge for 10 minutes with fresh air,
monitor sensor voltage, and re-zero.
Battery was discharged,
sensor has destabilized.
Charge battery, wait up to 24 hours
for sensors to stabilize, and re-zero.
Sensor cell life has expired.
Call E INSTRUMENTS for
replacement.
Temperature
Thermocouple
Thermocouple is not
connected
Check electrical connections
running to the probe
Infrared CO
2
No response from infrared
system
Zero period must be at least 45
seconds.
Zero the instrument
again with a cylinder ZERO AIR
.
Infrared system is reporting
error code
Infrared system may need
maintenance.
Velocity
Velocity probe/Pitot Tube is
not connected
Check probe and connections.
Bluetooth
connection failure
Connection Failed
Redo connection process
