Transcript Carbon Monoxide and Carbon Dioxide Detector

Carbon Monoxide and Carbon Dioxide Detector
Lab Methods Day
June 25, 2013
Taylor Myers
What does the tool measure?
 Carbon Monoxide Concentration
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% of CO, by volume, in the air
Digital readout
Analog output 0/2/4 to 20 mA
 Carbon Dioxide Concentration
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% of CO2, by volume, in the air
Digital readout
Analog output 0/2/4 to 20 mA
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How does it work?
 700o 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
How do we post-process?
 Voltage
measurements
concentrations.
must
be
calibrated
to
 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)
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What are the limitations?
 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.
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Additional information
 Siemens ULTRAMAT 6 (google it)