TM 10-6665-297-13&P
SECTION 3
CALIBRATION AND ADJUSTMENTS
3-1
GENERAL OBJECTIVES
In general, CD800/830 and CD802/832 calibration consists of setting ZERO and GAIN adjustments on
the control module so that 0 to 100% L. E. L. gas-air mixtures at the detector drive the control module
meter indicator between 0 to 100% readings. Because each specific combustible gas releases energy
upon oxidation at a different rate than another, different gases require different calibrations. After
calibration has been completed, control module WARN and ALARM potentiometers may be adjusted to
switch warning and alarm relays in response to designated % L. E. L. gas-air mixture levels at the
detector. Then a RANGE potentiometer is set to drive the meter indicator full-scale when the TEST
pushbutton is depressed, and a RECORD potentiometer may be adjusted to operate a recorder at
desired voltage levels.
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CALIBRATION
Calibration procedures are required for three different alarm system applications:
1.
Individual detectors (CD800/830 or CD802/832).
2.
Detectors paired with one CD800/830 control unit.
3.
One or two detectors per control unit sampling volatile hydrocarbons with flash points below 700 F.
Select and follow the procedure appropriate to the existing system.
NOTE: New installations and operating installations with new detectors should be rezeroed with no
combustible gas at detectors after 24 hours of operation and again after 1 week of operation.
3-2.1
CALIBRATING A SYSTEM WITH ONE DETECTOR PER CD800/830 CONTROL UNIT OR
INDIVIDUAL DETECTOR OF CD802/832 TWO-CHANNEL CONTROL UNIT. Two people and the
following special tools are required to calibrate the gas alarm system:
Portable Combustible Gas Indicator
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