Oldham OLCT 200 User Manual page 70

9.2.1 IR-Methane Sensor
The methane IR sensor is only intended to monitor methane gas. As seen in Figure
9.1, the cross-sensitivity of the methane IR sensor does not permit accurate measure
of other combustible gases. It should be noted however, that the Methane-IR sensor
WILL respond to other combustible gases and is not Methane specific.
Figure 9-1 Cross-sensitivity chart for OLCT 200Methane IR Sensor.
The output of the IR sensor can be disrupted by sudden changes in temperature. If
there is an excessive change in the ambient temperature, gas sample temperature or
flow rate, then the output signal will be monmentarily frozen. Correct operation is
restored when the effects of the transient have settled. Rates of change in the ambient
temperature should be restricted to 2C/minute and gas flow rates kept below 0.6
L/minute.
Extreme pressure variations will cause errors in readings. The unit should be
recalibrated if the atmospheric pressure change is greater than 10% from the orignial
pressure.
Do not expose the sensor to corrosive gases such as Hydrogen Sulphide.
Do not allow condenseation to occur inside the sensor.
OLCT 200 User Manual | 70