Ammonia Safe Area Fixed Gas Detector FGD4 Series, Loop Powered 4 To 20mA Transmitter Using Electrochemical Gas Sensor Technology 

 

The FGD4 Safe Area Gas Detector uses electrochemical sensor technology to detect the Ammonia gas level in the atmosphere. The detector uses the industry standard 4-20mA current loop to both power the detector and to convey the gas levels detected to a separate control unit such as the Status Scientific Controls LC Series. This means that under zero gas conditions 4mA is drawn from the supply, and under full scale gas conditions 20mA is drawn from the supply. The current varies linearly for gas levels between zero and full scale. The detector head uses a two-wire connection. 

 

Calibration of the FGD4 can be carried out simply by using ZERO and SPAN buttons inside the instrument provided that the concentration of the calibration gas is the same as that used for factory calibration of the detector (refer to the instrument calibration certificate for details). 

 

Alternatively, the purpose designed plug-in hand held configuration unit shown below may be used together with any appropriate test gas concentration.