The ppmCO2 Slave Analyser Module is used to measure the concentration of carbon dioxide in the sample gas.

The CO2 Slave unit functions in conjunction with an O2 Master unit by means of an RS485 connection (iNET bus).  CO2 data is also output via the O2 Master Ethernet interface.

Like the O2, the CO2 unit features barometrically corrected & normalised gas concentration information.  The main display is of LED type for clear at a glance viewing from a good distance.  The VFD (Vacuum Fluorescent Display) also provides clear from any angle.

The CO2 sensor used inside this module is a non-dispersive infrared (NDIR) type which is highly accurate, responds quickly, and has an indefinite service life.  The NDIR sensor comprises a sample chamber through which the gas to be measured flows.  The adsorption of infrared light is measured inside this chamber by use of a modulated infrared source, an optical bandpass filter and a specially linearised detector system.

Unlike other sensors/analysers available on the market, the Fathom Systems CO2 analyser is fully helium tolerant, as the sensor components are separated from the sample by sapphire optical windows.  The accuracy of the system is also significantly higher than other systems, as the sensor has a 25ppm resolution which meets the specification dictated by DNV & Lloyds at 300m water depth.

The CO2 Slave can also provide two high resolution (16-bit) analogue 4-20mA outputs which are configurable for various outputs such as corrected or uncorrected readings or barometric pressure.  This together with an alarm status contact enables the unit to replace a conventional analyser which provides a 4-20mA output for PLC/SCADA/HMCS system.

Both an O2 & CO2 unit can provide two 4-20mA analogue outputs giving 4 outputs per system.