Ametek 900

5-70 | Model 900 ADA / Model 930 Sulfur Pit Analyzers
MS Code MStatus Alarm Type Condition / Description and Suggested Corrective Action
4 3 Fault f On-Chip ADC
Two possible errors may be occurring, either:
• The Microcontroller board’s internal analog-to-digital (ADC)
converter is not responding.
and/or
• One or more of the RTDs has failed, causing its temperature
zone to read “181.4 °C”.
Upon detection of this fault, the analyzer will automatically switch
to Backpurge mode until the alarm has been corrected.
Note: A temperature zone can indicate “181.4ºC” but not trigger
this alarm if its Set Point is set to ‘0’ (typical for a spare
temperature zone).
Corrective Action:
Take appropriate safety precautions, open the Electronics Enclo-
sure, and:
• Replace the Microcontroller board.
and/or
• Check the current temperature (Show MAI screen) for each
temperature zone and compare it to its Set Point temperature
(TStPt screen).
To check the ASR900 Sample Probe Set Point temperature,
view the PrbTPara screen.
• Using an Ohm meter, measure the resistance of the RTD for
the zone which caused the alarm (view the TType screen to
determine sensor type). Test it for an open circuit. If the RTD is
faulty, contact AMETEK for assistance.
• Replace the Temperature Daughter board. Contact AMETEK
to verify operation before removing this board.
• Replace the Termination board. Contact AMETEK to verify
operation before removing this board.
(Show MAI)
RUNF6 81..8
(TStPt) RUNF4 01..4
(PrbTPara) RUNF1 71
(TType) RUNF4 41..4