Understanding Infrared Thermography Reading 3

The equipment necessary to perform infrared materials discontinuity detection
must include thermographic scanning instrumentation and the means to
handle the test samples and to generate and control the injection or extraction
of thermal energy to or from the samples. These can include hot and cold air
blowers, liquid immersion baths. heat lamps. controlled refrigerants. electric
current, scanned lasers and induction heating. The goal is to maximize the
normal thermal flow, minimize the lateral thermal now (along the material
surface), cause no permanent damage to the test samples, minimize and
carefully meter the test time and generate the most uniform thermal pattern
possible across the surface of the test sample. Because the source of energy
is finite in dimension, the generation of a uniform thermal pattern on the
sample surface is often difficult to accomplish. Using a personal computer
with appropriate diagnostic software. a thermographer has access to
numerous image manipulation routines including keyboard controlled image
manipulation and subtraction. This image subtraction capability can be quite
effective in compensating for limitations in heating pattern uniformity.
Charlie Chong/ Fion Zhang