HML and HML-N carbon monoxide transmitters are designed for detecting carbon monoxide in underground parking garages and parking halls. The measuring cell is an environmentally friendly electrochemical cell with a long life, good long term stability and high accuracy. As the sensor is heated, the transmitter is working also in low temperatures down to -30°C.

The output of 0…10 V or 4…20 mA is available on the settable ranges of 0…100 or 0…300 ppm CO concentration for controlling ventilation. Please note during the warm-up time at the commissioning; output is 0V or 4mA and the display of HML-N is blinking.

The function of the transmitter is recommended to be checked regularly e.g. once a year. Checking can be made by using a reference gas of 150 ppm CO.

Note! The reference gas must contain also oxygen O2, because of the measuring principal of the sensor cell. If necessary the transmitter can be calibrated by using
HML-C tool. We recommend using of HMV exchange kit to ensure the function of the transmitter. By changing the sensor module, values corresponding values of the new
transmitter, can be guaranteed. Plug-in connection makes changing very easy.

Each transmitter and HMV has its own identified calibration certificate.