6. Troubleshooting
Symptom
Possible Cause
Fault isolation/Solution
PM values seem
incorrect
Sample flow incorrect
Sample and/or purge filters dirty
Gain factors incorrect
Offset factor incorrect
Check sample flow and adjust to correct
value using flow adjusters
Replace filters
Perform span calibration
Perform zero calibration
Flow cannot be set to
1LPM
Dirty filters
Old/faulty pump
Flow adjusters/fittings leaking
Replace filters
Change pump
Replace flow adjusters and fittings
“NR” or “99999” in
Data table(No
response)
Occasional NR or
“99999” in Data Table
Frequent “99999”
No Response from Sensor module.
Not connected correctly.
Bus cable
Computer too slow
RF noise in environment.
RS485 bus cable is faulty
Module RS485 chip faulty
RF noise in environment.
Check the electrical connector on the
sensor module is firmly connected
Check RS485 bus cable continuity
Test with a faster computer.
Try to reduce RF noise
Replace bus cable
Remove one module at a time to identify
faulty module and then replace.
Try to reduce RF noise
No communication
over RS232
RS232 cable disconnected
Control Module Failed
Reconnect cable
Replace Control Module
PC Data logging
stopped
USB to serial hub not working
Check USB connectors. Check the serial
hub is present on the device hardware
menu in the PC. If not reload driver
software and re-install.
No data on SD card
Card not correctly installed in slot.
Data logging interval set too large.
Data card module fault
Turn off Dust Profiler and install card in slot
correctly.
Set logging interval in configuration to a
lower interval.
Send control module to factory for
replacement module.
