Figure 4-3. Water Tank Glass Sight Gage
(a) If necessary, turn meter mechanical screw
adjustment to set indicator needle to zero on meter
New installations and operating
installations with new detectors
(b) Turn power on at control unit and operate
detector for at least five minutes before calibrating.
(c) Using a portable combustible gas indicator,
hours of operation and again after 1
test air at detector. If air is free of combustible gases, go
week of operation.
on to step (4) (a). If air is not free of combustible gases,
(2) Calibrating a System With One Detector
or if portable test instrument is not available, apply Zero
Per Control Unit. Two people and the following special
Gas/Dry Air or 100% Nitrogen Gas to the detector as
tools are required to calibrate the gas alarm system:
(a) Portable Combustible Gas Indicator.
1. Using Gas Calibration Kit 0023-7260,
appropriate sample cup and gas calibration cylinder
(0023-4003 100% Nitrogen or 0023-4004 Zero Gas/Air),
attach regulator assembly, kit to gas cylinder. Close
100% nitrogen or 0023-4004 Zero-gas/dry-air if
regulator valve and attach hose and sample cup to
combustible-gas-free air does not exist at the detector.
2. Open regulator valve to fill cup with sample gas
gas equivalent to that expected at detector location.
and displace air.
(3) Perform sampling and adjustment procedures
(4) Calibrating a System With One Detector
for calibration as follows:
Per Control Unit or Individual Detector of Two-Channel
System will not operate properly
(a) Turn adjustment screw of ZERO potentiometer
unless the remote detector voltage is
first set. Voltage setting should be
(CD800/830;R24;CD802/832: Channel 2 R9, labeled 21;
checked and readjusted, if necessary,
R13, labeled 22) as necessary to set meter indicating
each time a detector element is
needle at zero reading on meter scale.
for specific instructions on voltage
(c) 1 thru 3 above, but with gas cylinder containing gas of
known concentration, expose detec-