Teledyne 1220 - Multipoint flammable gas and vapor detection system - Manual (Page 43)

Multi-Channel Combustible Monitor Operation 4
4-15 Teledyne Analytical Instruments
amounts (percentages) of methane mixed with air. Table II lists calibration
factors for the TAI Combustible gas sensor which can be used to calibrate
these detectors to indicate the percent LEL of the specific gases. These
calibration factors are based on the use of methane in the air as the calibra-
tion gas and take into account both relative response and LEL of the
specific gases.
To use these calibration factors, multiply the percent volumeric
concentration of methane in the calibration gas by the appropriate calibra-
tion factor. The number thus obtained is the meter reading to which the
instrument should be spanned, in accordance with the calibration proce-
dures, when the sensor is exposed to the calibration gas. When so adjust-
ed, the instrument will be calibrated to indicate the percent LEL of the
selected gas.
Use the following formula to determine the value to enter during the
span calibration procedure:
V = CH4 x CF
Where:
V = Value to enter during span calibration
CH4 = Percent methane in air
CF = Calibration Factor from Table II
EXAMPLE:
CH4 = Certified Calibration Gas = 2.2% methane in air
Gas for which calibration is desired = Ethane
CF = Calibration Factor from Table II = 28
V = Calibration Meter Reading = 62 = 2.2 X 28
Using the calibration procedures in this manual, adjust the span so
that with calibration gas flowing through the calibration adapter, a meter
reading of 62 is obtained. The instrument will then be calibrated to indi-
cate 0 to 100% LEL of Ethane.