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“Concrete Moisture Emission Vapor Testing: Different Tests, Different Results – Why is That?”
“The two most popular concrete moisture vapor emission test methods are the ASTM F1869 calcium chloride dome test and the ASTM F2170 in situ relative humidity drill test. These are very different and distinct in methodology and results; they cannot be compared to each other. Both are quantitative result tests, though they measure different things. To compare the results of these two tests is like comparing a person’s blood pressure and temperature. Each one alone has a meaning, but they cannot be compared for any specific result.
The calcium chloride dome test, which takes between 60 and 72 hours, will give a result of an emission rate, as pounds per square foot per a 24-hour timeframe. A gallon of water weighs eight pounds; therefore the measurement is roughly how much moisture vapor changed to a liquid is emitted. With this test, you get an actual weight that can be compared with a physical property.
The relative humidity, drill test (in situ), on the other hand, will give results by inserting a probe into a drilled hole, at 40% depth of the total thickness of the concrete substrate and letting it acclimate for one to two hours. The probe does not measure the weight of condensed vapor, but rather the percentage of humidity in the concrete substrate at that depth.
There are advantages and disadvantages to both types of tests…”
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“Concrete Moisture Emission Vapor Testing: Different Tests, Different Results – Why is That?”
By: Robert Blochinger
Floor Covering Installer
August 12, 2013