TM 10-6665-297-13&P
3-2.1
Calibrating a System with One Detector per CD800/832 Control Unit or Individual Detector of
CD802/832 Two-channel Control Unit (continued)
5.
Using J-W Gas Calibration Kit 0023-7260 or Professional Calibration Kit 51-7070, expose detector to
sample gas of known concentration until meter reading stabilizes.
If desired, known concentrations of propane gas may be used to calibrate gas detection systems for
correct response to gases other than propane as follows:
a.
On conversion chart (Figure 3-2) horizontal scale for "% L. E. L. GAS, " find point representing
known percent L. E. L. concentration of propane gas sample applied. For example: The standard J-
W gas cylinder contains 1 percent propane by volume in air, a concentration known to be at 46
percent L. E. L.--for which the 46-percent point on the horizontal scale at the bottom of the chart
would be selected.
b.
Follow up from the selected percent point vertically to diagonal line representing gas for which
calibration is wanted.
c.
From point found on diagonal line, follow horizontally to left and read percent L. E. L. meter reading
on vertical "% L. E. L. METER READING" scale. To continue the example: Following up from the 46
percent pointof the horizontal scale to the diagonal line representing ethylene oxide, and then
following from the point on the diagonal to the vertical scale at left indicates a percent L. E. L. meter
reading of approximately 50 percent for ethylene oxide gas calibration.
For gases that are not represented on the chart of Figure 3-2, the multiplying (K) factors in Table 3-1
may be used to calibrate with propane for gases other than propane. Or the multiplying factors may be
used as a preferred alternate method to use of the chart. For example, to use J-W standard propane gas
cylinder 0023-4009 (1 percent by volume; 46 percent L. E. L.), multiply 46 by the ethylene oxide
multiplying (K) factor of 1.09 as shown in Table 3-1, and get 50 percent as calculated percent L. E. L.
reading for ethylene oxide. If using the Professional Calibration Kit 51-7070, multiply kit percent L. E. L.
output (determined per instructions with kit) by the multiplying factor for the gas for which calibration is
desired.
6.
While continuing exposure of detector to sample gas, adjust GAIN potentio-meter (on CD800/830
circuit board: R10; on CD802/832 circuit board: R7 for Channel 1 and R18 for Channel 2) so that
meter reading matches percent L. E. L. concentration of sample gas or percent equivalent for
another gas.
Recommendation: For safety factor, adjust GAIN potentiometer to obtain meter reading 10 percent
higher than known concentration of applied sample gas.
23-9617
4/4/78
3-4
