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General
The Building Division of
Stockton Infrared Thermographic Services, Inc. (BuildSCAN™) has
performed qualitative infrared thermographic surveys of CMU walls on
thousands of buildings. We bring to our clients experience,
state-of-the-art high-resolution infrared imagers, digital recording
equipment, techniques that have been refined over many years and the
attitude that we are going to obtain the best imagery possible and
produce a professional report in a timely manner. Our deliverable
product is the best in the field of infrared thermography on the market
today.
Understanding Building Infrared Imagery
Infrared imagery is often a grayscale picture whose scales (or shades of
gray) represent the differences in temperature and emissivity (opposite
of reflectivity) of objects in the image. As a general rule, objects in
the image that are lighter in color are warmer, and darker objects are
cooler. No object in the images is detected via visible light
wavelengths (400-700 nanometers) rather, only from infrared wavelengths
in the 3000-5000 nanometers or 3-5 micrometers (microns) range. Lights
and other relatively hot objects are very evident, but as a result of
their heat---not light emissions.
When an image is taken with an infrared camera, it is often recorded
onto videotape and digitally saved to an on-board PCMCIA card. The image
may be then modified in a number of ways to enhance its value to the end
user. In the case of the printout that will be enclosed with this
package, the building images will be digitized, saved and converted to
TIFF images through the use of FLIR Systems Thermotechnix Thermonitor
Pro and Researcher software. The images will then adjusted for color,
contrast and brightness before being scaled and placed in a PowerPoint
file. The file is then printed on photographic paper by using a photo
quality printer. Images are recorded onto a digital videotape via
S-Video direct cabling, then recorded onto any format that is desired by
the client, for example VHS, 8mm, DVD, mini-DV or CD-ROM.
Infrared Testing Methodology
To find out what is inside a wall, we scan them looking for surface
temperature differences. These differences in temperature indicate a
difference in mass, since heat energy is gained and released at
different rates from objects of different densities. Since we scan the
walls with extremely sensitive infrared cameras, we can see the patterns
as a ‘picture’ of the different densities. Wall areas that contain
grout, insulation or are empty are displayed as a different color (or
shade of gray). Since we can “see” all areas of different mass, we can
immediately determine if there is a component misplaced, incomplete or
missing. When deficiencies are found, we make a matching visual image
with a high resolution digital photo camera for reference. The
orientation of the building to the Sun, the weather - as much as 3 days
prior to the survey, the type of surface, status of the HVAC systems and
many other factors make the ‘window’ of uneven heat dissipation
different for each building and building component. For this reason,
surveying must be done day and night, under varying conditions.
Old-fashioned methods of
testing (on-site testing companies, installing Inspection ports,
performing destructive testing and X-raying) are generally ineffective
and expensive. An experienced BuildSCAN™ infrared thermographer can
successfully survey just about any building, given proper thermal
transient conditions. Infrared thermography can be used on the job site
as an effective way to improve the quality of construction and the
accountability of the contractors. This brings benefits to the building
owner, general contractor, structural and thermal engineer and to the
building industry in general.
Advantages of BuildSCAN™ Infrared Testing
- The building owner gets
a permanent record of the building, documenting that it is safe,
code-compliant and built to the architect’s specifications.
- Confident that what he
puts in the specifications will be built and verified, there is no
need to ‘over-design’ the building to compensate for inevitable,
previously unseen faults. This will save the owner time, money and
simplify the construction process.
- General contractors can
reduce the costs of inspections, since the building can be verified to
specifications at any time during the construction. If faults are
discovered, high quality reports can be generated and presented to the
responsible party quickly, so that repairs can be carried out in a
timely manner.
For more information on
this testing method and to download a white paper on the subject...
HTTP:
http://stocktoninfrared.com/thermppr.html
Acrobat:
http://stocktoninfrared.com/PDF/Greg'sSPIE1999.pdf
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