Instruction 0011-9026
Page 17
Figure 17. Checking CO
2
of gas
designed
furnace
(sampling
tube
inserted
through
draft
diverter;
fl
ue gas temperature test can
be
made
at
same
point).
5.7 General FYRITE Applications
It is only possible to specify a few general rules for such applications. Where possible,
sample should be obtained at a point where the gases are well mixed to a uniform
composition. Where this is impossible; it will be necessary to average a number of
measurements taken at different locations to obtain representative average. Where
gases being sampled are not saturated with moisture (many non-combustion applica-
tions), it is very important to maintain the wool packing of Filter Saturator Tube in a
moist condition.
NOTE:
The FYRITE is calibrated to analyze gases which are
normally saturated with moisture. Failure to moisten wool
packing in
fi
lter saturator tube with water will cause FYRITE
to indicate slightly lower than actual gas concentration
.
Where special length sampling lines are required, add one more bulb squeeze to the
18 required with standard Sampling Assembly for each additional 3 cubic inches
(50cc) volume of special sampling line.
EXAMPLE:
For each 9 ft. of 3/1 6 inch (I.D.) additional
length of sampling line, add one more bulb squeeze.
If it is necessary to trap a sample over water for later analysis, a minimum of 900 cc of
sample will be required. If sample is trapped over water, it is good practice to use 10
to 15% NaCl (table salt) in the water to minimize absorption of CO
2
or O
2
by water.
Trapping a sample over mercury will eliminate any possible error due to absorption of
CO
2
or O
2
.
5.8 Altitude Correction Table
