Carbon Monoxide and Carbon Dioxide Detector Lab Methods Day June 25, 2013 Taylor Myers

2  Carbon Monoxide Concentration % of CO, by volume, in the air Digital readout Analog output 0/2/4 to 20 mA  Carbon Dioxide Concentration % of CO2, by volume, in the air Digital readout Analog output 0/2/4 to 20 mA What does the tool measure?

How does it work?  700 o C Infrared source is split into two beams  A reference beam passes through a reference cell filled with N2, essentially unattenuated and reaches the right side of the detector  The sample beam passes through the Sample Gas and reaches the left side of the detector.  A few other things work together to minimize interference.

How do you use it?  A micro-pump and flow controller allow air into the sensing system  There can be no dust or condensation in the system, so first the sample gas is passed through a desiccant (Drierite)  A digital read out of the measurements is displayed  Analog readouts are possible through voltage measurements

5 How do we post-process?  Voltage measurements must be calibrated to concentrations.  There is a lag time (time before sample reaches the detector)  There is a mixing time (time in which a pulse sample is smeared into an output signal)

What are the limitations? 6  All dust must be removed  All water must be removed  There are finite ranges over which the CO and CO2 concentrations can be measured.  It is broken.

Additional information  Siemens ULTRAMAT 6 (google it)