We’ve spent the past several weeks discussing heat transfer. Radiation is a special mode of transfer because that is the mode by which energy is transferred from surfaces to our imagers.
All of what we see in the thermal image is nearly always based on the amount of radiation emitted from or reflected by the surface. [...]
For young children and pets, the first look in a mirror can be very confusing! They may be asking themselves. “Is that real or…?” Most thermographers share a similar exasperation the first time they see a thermal reflection, most commonly from a bright piece of metal. Many go on to understand that reflections are not [...]
For the past several weeks, we’ve been reviewing heat transfer. Thermographers must understand the basics if they are to successfully interpret their images. Over the next two weeks, we’ll wrap up the review with a discussion of radiation.
Electromagnetic radiation is not only a powerful mode of heat transfer, it is also the way energy moves [...]
As we continue the discussion about convective heat transfer, it is useful to define two types of convection, natural and forced. When quantities of fluids are moved in either way, we also use the term “bulk energy transfer” because it is really the movement of the fluid itself, and the energy inherent in it, that [...]
When heat transfer occurs in fluids—defined simply as non-solids—the rate and total transfer are governed by several factors, two of which are easily known: temperature difference and area. More challenging to define precisely is “h” or the Convective Heat Transfer Coefficient. This all-important variable is the amalgamation of a number of influences on heat transfer [...]