Chuck, with all due respect, you are just using semantics. You could have been just as accurate to say that a moisture meter doesn't measure moisture- it measures electrical continuity (typically) which can be interpreted by an experienced user to determine moisture content.
You wrote:
Thermography does not detect moisture, Infrared Thermography measures temperature. Variances in temperature may indicate the presence of moisture. A Thermography photograph would show the pattern of differential temperature.
Allow me to add a little something to the end of what you wrote:
A Thermography photograph would show the pattern of differential temperature, which might reveal a pattern of moisture when there is one.
I have seen a thermography machine used and it seemed pretty good to me at showing a very different color where water was thrown on a carpet. Granted, I knew it was water because I saw it thrown there as a test. But in a real situation I could imagine that if one spot on a ceiling was known to be wet (from touching it or testing with a moisture meter etc), and the thermography machine showed that specific spot and the area all around 12 feet in every direction to be the same color that would be a pretty good clue that there was a 24 ft diameter wet spot.
If I was looking at the windows of your house I would know I was looking at the windows of your house. If the thermography camera was pointed at a hot exhaust pipe I would know that the color difference had nothing to do with moisture.
But to be honest I have never paid anyone to use one of those machines so maybe I am totally wrong. In the scenario described about the EPDM roof if I knew there was a dispute about interior water intrusion being from a wind created opening or not I would just have the roofer do an interior inspection together with the roof inspection. That usually increases the cost of a professional roof inspection by $100.00 and its usually exactly what the carrier likes done.
found on the web:
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AMERICAN LEAK DETECTION EMPLOYS INFRARED THERMOGRAPHY TO DETECT WATER LEAKS
Infrared Technology Eliminates Costly Destructive Probing Methods
Dallas, Texas – American Leak Detection (
http://www.alddfw.com), introduces Infrared Thermography as another piece of cutting edge technology that allows hidden water leaks to be detected. With Infrared Thermography, American Leak Detection can identify problem areas that can’t be seen by the naked eye - eliminating destructive probing methods. The infrared inspection can detect not only hidden water leaks and their origin, but also moisture that cannot be physically reached with moisture meters and even detects unseen pests.
“The benefit to consumers is that we are able to see things the naked eye cannot, which eliminates the old methods of finding these types of leaks – such as cutting holes in walls, ceilings, and through floors. This of course, saves the home owner remodeling expenses.” says Will Knell, Director of Operations. “In the past, these hidden leaks often went undetected until they were very obvious, and therefore made repairs more costly”
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RoofScanIR™ Service www.roofscanir.com [check out the photo on their website]
During the day, the sun radiates energy onto the roof and into the roof substrate, and then at night, the roof radiates the heat back into outer space. This is called radiational cooling. Areas of the roof that are of a higher mass (wet) retain this heat longer than that of the lower mass (dry) areas. Infrared imagers can detect this heat and “see” the warmer, higher mass areas, during the “window” of uneven heat dissipation. Heat loss and other IR services can be performed at the same time.
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http://www.oandsassociates.com/infr...raphy.html O&S Associates, Inc. is a diversified and multi-disciplined Consulting Engineering firm.
Infrared and Roofing
Infrared cameras enable roofing professionals to measure and compare the temperatures of roofing substrate materials that are wet—presumably from leaks, and roofing substrate that is dry. The dry roof areas cool faster after sunset and warm up faster than the wet areas after sunrise. This causes a temperature difference that can be imaged.
The Practice is addressed by the American Society for Testing & Materials (ASTM) in measurement standard C1153, "Location of Wet Insulation in Roofing Systems Using Infrared Imaging."
Water enters the roof system by means of splits, holes or faulty flashing, causing the roofing components (i.e. insulation, felts, decking) to become wet. The wetter areas store more heat from daytime solar loading and remain warmer at night. Reduced thermal value of water damaged insulation and/or decking materials also allows for heat transfer of interior energy through the wet components during the colder months. It is this thermal radiation of water present in the roof that the infrared camera records. The hot spots are visible on the surface of the roof when viewed through the infrared camera. Buildings with concrete decks rely mainly on solar loading to heat the roof system, therefore scanning concrete decked roof systems during the winter and roof sections that remain in shadow during the day (below units, overhangs, under gratings, etc.) provide negligible thermal profiles.
Moisture entering the roof system at penetrations and base flashings that does not affect the insulation will not be detected by the infrared camera because the moisture can flow directly into the building interior, leaving the insulation unaffected. This can typically occur at pipe penetrations, pitch boxes, ventilators, mechanical units, skylights and masonry walls.
The roof top is scanned during the evening- shortly after sundown in the winter, and one to two hours after sundown in the summer (these conditions may vary due to the type of roof membrane). Scanning at night allows for sufficient cooling of the roof surface and eliminates solar reflection resulting in a more accurate scan.
The information can now be presented as colorized thermograms, with different colors or shades representing different surface temperatures. Variables that can affect the thermal radiation include wind velocity, cloud coverage, and material density. A color bar along the side of the thermograms indicates temperatures in ascending degrees with warmer areas at the right of the bar (typically the wettest areas in roofing and driest areas in the masonry scan). Corresponding visible light photographs help to orientate the thermograms, as well as give clues to water entry points.
Why use Infrared Thermography on Flat Roofs? Infrared imaging is a proven method for identifying and defining moisture problems in your roof. This will enable you to develop a more sophisticated roof asset management program, make more informed decisions regarding roof budgets and will help you plan repairs.
By using infrared thermography, we find the trapped moisture and mark the wet areas on the roof with marking paint, so that roof repairs can be
made surgically - without the tremendous expense of replacing the entire roof.
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and for something different, the Colombia Missouri utility gives free IR thermography inspections to find electrical HOT spots instead of moisture:
How can an Infrared Thermography Inspection help?
Columbia Water and Light business customers can receive a free infrared thermography inspection to find problematic equipment before it causes downtime. An infrared inspection can reveal hot spots in a number of areas:
low voltage switch gear
power distribution
motor control centers
control panels
packaging/assembly lines
distribution conveyers
palletizers/unitizers/stretch wrap equipment
facility wiring and breaker panels