6-52   |   Model 931S / Model 932S UV Analyzers
  Decimal  Alarm
 Bit  Value  Type  Alarm Condition / Description and Suggested Corrective Action
 6  64  Fault  f: Low ow detected
A low sample gas ow has been detected. This alarm will be delayed by the time 
(seconds) entered in the Flow Switch Alarm Time Delay eld on the Alarm 
Setting and Stream Switch Parameters dialog box.
Note:  This alarm is used only by analyzers equipped with the optional ow 
switch.
  This alarm can be factory-set as a Warning or a Fault from the Alarm 
Type eld in the Alarm Setting and Stream Switch Parameters dialog 
box, based on customer requirements. A Fault indicates a serious failure 
has been detected and the data is not valid – the analyzer will switch 
the sample system to shut-in/o mode. For a description of this alarm 
if congured as a Warning, refer to the w: Low ow detected alarm 
description earlier in this section. 
Corrective Action:
•  Check the probe valves to ensure they are open.
•  Check the sample system to ensure there is adequate ow and there are no 
plugs.
•  If your system uses an aspirator to move the sample gas, adjust the aspirator 
air to ensure a proper ow rate, as indicated on analyzer drawings.
  Also, check the aspirator air line for damage or bends.
•  Check the ow switch for plugs and/or for an open circuit.
Take appropriate safety precautions, open the Upper Enclosure, and:
•  Check the Micro-Interface board by simulating the low ow switch output.
Setup (tab)Alarm/
Stream Switch