Teledyne First Responder CG User Handbook Manual page 47

OPERATION
'SAMPLE FAULT'
This indicates a problem with the instrument's flow due to
the sample path being blocked, water ingress, a blocked
filter or pump failure.
The pump will switch off. The sample path should be checked
and Button One pressed to clear sample fault and re-start
the pump.
'CHECK ZERO'
This indicates that there may have been a zero shift due to
the presence of gas. Switch off the instrument and switch
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