GE Moisture Image 1 Series Service Manual page 88

June 2003
A-26
B: Special Case (cont.)
Note: If the saturation concentration at the desired ambient
temperature can not be found for any of these special case
hydrocarbons, the value at any other temperature may be
used, because K is constant over a large temperature range.
3. Find the moisture content in hexane, at an ambient temperature of
10°C, if a dew point of 0°C is measured with the GE Panametrics
hygrometer.
a. From the literature, it is found that C
temperature of 20°C is 101 PPM
b. Using a straightedge on Figure A-2 on page A-32, connect the
101 PPM saturation concentration with the 20°C ambient
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temperature and read the Henry's Law Constant of 5.75 on the
center scale.
c. Using the straightedge, connect the above K value of 5.75 with
the measured dew point of 0°C, and read the correct moisture
content of 26 PPM
moisture content scale.
4. Find the moisture content in an unknown organic liquid, at an
ambient temperature of 50°C, if a dew point of 10°C is measured
with the GE Panametrics hygrometer.
a. Either perform a Karl Fischer analysis on a sample of the liquid
or obtain a dry sample of the liquid.
b. Either use the PPM
or add a known amount of water (i.e. 10 PPM
sample.
c. Measure the dew point of the known test sample with the GE
Panametrics hygrometer. For purposes of this example, assume
the measured dew point to be -10°C.
d. Using a straightedge on the nomograph in Figure A-2 on page
A-32, connect the known 10 PPM
measured dew point of -10°C, and read a K value of 5.1 on the
center scale.
e. Using the straightedge, connect the above K value of 5.1 with
the measured 10°C dew point of the original liquid, and read
the actual moisture content of 47 PPM
for hexane at a
S
.
W
where the straightedge crosses the
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determined by the Karl Fischer analysis
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moisture content with the
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on the left scale.
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Application of the Hygrometer (900-901D1)
) to the dry
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