Start Up
After installation apply power to the unit. Allow the sensor to warm up for at least
15 minutes. For Ammonia sensors allow at least 2 hours for warm up time. Upon
power up the unit will display 00 on the LED display. If the LED display does not
indicate 00 then check to see if the ribbon cable connector is properly inserted. If
necessary unplug the ribbon cable and plug it back again. The connector is keyed
and can be inserted only one way.
During the warm up time the sensor may display reading other than 00. However,
the 4-20mA analog output will remain at 4mA (0 reading) and the alarm relay is
inhibited. The reading will slowly goes down to zero. After warm up time the
sensor will return to its normal operation. Refer to section “Adjust Alarm Set Points”
to modify alarm parameters. Change the alarm levels if different set-point is
desired.
The sensors are calibrated at the factory before they are shipped. However, it is a
good practice to check the accuracy by simply applying the calibration gas after the
warm up time and check to see if the concentration displayed is as desired. If
calibration is required then follow the steps in the Calibration procedure.
PT295 Series Toxic Sensor Rev 5.1
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