GE Moisture Image 1 Series Service Manual page 86

June 2003
A-24
A: General Case (cont.)
Complete the following steps to determine the moisture content from
the nomograph:
1. Using a straightedge on the two scales on the right of the figure,
connect the known saturation concentration (PPM
measurement temperature (°C).
2. Read the Henry's Law constant (K) on the center scale.
3. Using a straightedge, connect above K value with the dew/frost
point, as measured with the GE Panametrics' hygrometer.
4. Read the moisture content (PPM
crosses the moisture content scale.
Empirical Determination of K and C
If the values of K and C
S
hygrometer can be used to determine these values. In fact, only one of
the values is required to determine PPM
Figure A-2 on page A-32. To perform such an analysis, proceed as
follows:
1. Obtain a sample of the test solution with a known water content;
or perform a Karl Fischer titration on a sample of the test stream
to determine the PPM
Note: The Karl Fischer analysis involves titrating the test sample
against a special Karl Fischer reagent until an endpoint is
reached.
2. Measure the dew point of the known sample with the GE
Panametrics hygrometer.
3. Measure the temperature (°C) of the test solution.
4. Using a straightedge, connect the moisture content (PPM
the measured dew point, and read the K value on the center scale.
5. Using a straightedge, connect the above K value with the
measured temperature (°C) of the test solution, and read the
saturation concentration (PPM
Note: Since the values of K and C
hygrometer measurement and the test sample analysis must be
done at the same temperature. If the moisture probe
temperature is expected to vary, the test should be performed
at more than one temperature.
) where the straight edge
W
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are not known, the GE Panametrics
from the nomograph in
W
of water.
W
).
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vary with temperature, the
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Application of the Hygrometer (900-901D1)
) with the
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) with
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