You can connect your Series 900 or 930 monitor to a PLC or current sensing device via the 4-20mA output to provide gas concentration information.
The full scale (20mA) value is factory set but you can change the output scale in the fixed monitor configuration software.
If the sensor fails, the output will be 20mA. We recommended you use the DIAG output to alert a sensor fault condition.
The 4-20mA output loop is opto-isolated from the monitor and we recommend a separate power supply with a voltage in the range 12-24V applied with the correct polarity. This produces the most reliable connection method. If opto-isolation isn’t important, the 4-20 mA loop can be powered by the same power supply as the unit.