User Manual

cGas Ammonia Vent Line Transmitter - Addendum Rev. B | 2022.09

5.6.1 Calibration Adapter Plug Doesn’t Fit

Use a slight twisting motion as you gently push the calibration adapter plug (p/n: CET-7000-

CAP) into the sensor opening. If it is hard to insert, moisten the O-ring seal slightly then try

re-inserting it.

5.6.2 Zero Fault

If the zeroing process fails, the cGas Detector will show a Zero fault. This will happen if the

ambient gas readings are at an unacceptable level due to not enough clean air - there is

enough residual target gas in the environment or other gases that are interfering with the

sensor seeing oxygen.

5.6.3 Span Fault

If the cGas shows a Span fault after trying to calibrate, it is possible that the sensor is dead

or the device isn’t seeing the gas (cylinder is empty, regulator or adapter plug is not attached

properly, tube is blocked, kinked, etc.).

Span Fault

197 AD 1

Check all connections and possible interferences and try a complete calibration procedure

from the beginning again to see if this corrects the fault. If a second calibration does not

resolve the fault then the sensor needs to be replaced. Over time, a sensor degrades and

when it has gone beyond an acceptable level, it has reached its end of life and will no longer

pass a calibration. If replacing the sensor does not correct the fault, please contact Technical

Service at help@cetci.com.

5.6.4 Zero Override

If the gas level (possible residual gas) is too high, but still within the override range, the

display will indicate that an override is required.

Override?

-?????

To override the value use the UP button to select Y and press ENTER. To keep the original

zero value, leave the indicator on N and press ENTER.

5.6.5 Span Override

During the Span calibration, readings are taken and from the results sensitivity is calculated

and compared to the original sensitivity of the sensor at the time of installation. If this

sensitivity is below the override range, but above the fault limit, the display will indicate that

an override is required. To override the value use the UP button to select Y and press ENTER.

To keep the original value, leave the indicator on N and press ENTER.

Override?

1953 AD 19

6 SENSOR REPLACEMENT

p/n: VLT-NH3-SEN

The catalytic ammonia sensor has a lifespan of approximately 2 to 3 years under normal

air conditions. The sensor may need replacing sooner if is is poisoned by exposure to a very

high concentration of ammonia.