PT495 Series Detector
(Ultra1000)
Rev 5.11
30
Alarm Conditions
Low Alarm
When the gas concentration displayed reaches the predefined alarm set point
then the low alarm condition exists. The low alarm relay is energized.
High Alarm
The sensor is said to be in high alarm condition if the gas concentration reaches
the high alarm set point. The high alarm relay is energized.
Fault (Sensor Fail)
The transmitter is in Fault (Malfunction) condition when the sensor assembly
malfunctions. In Fault condition the 4-20mA output generated would be less
than 1.0 mA. The Display will show “Sensor Fail”
Note: Fault Alarm relay is normally energized. This is to provide fail safe
operation in the event of power supply failure to the unit.