thermography

thermography (thûr'mŏg`rəfē), contact photocopying process that produces a direct positive image and in which infrared rays are used to expose the copy paper. In a specially designed machine the original is placed in contact with a copy paper containing a heat-sensitive substance. As the infrared rays produced in the machine impinge on the dark or printed regions of the original, the heat generated is transferred to the adjoining areas of the sensitive paper. These areas become dark as well, creating an image of the original. As infrared rays are difficult to focus, the image formed is lacking in sharpness, resolution, and detail. The copies remain sensitive to heat, so that they may darken further with age. The advantages of this process are that it is low in cost and fast and can be performed with simple equipment.

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thermography [thər′mäg·rə·fē]

(engineering)

A method of measuring surface temperature by using luminescent materials: the two main types are contact thermography and projection thermography.

(graphic arts)

A photocopying process in which the original copy is placed in contact with a transparent sheet and is exposed to infrared rays; heat from carbon or a metallic compound in the text ink then causes a chemical change in a substance laminated between the transparent sheet of paper and a white waxy back.

Photography that uses radiation in the long-wavelength far-infrared region, emitted by objects at temperatures ranging from -170°F (-112°C) to over 300°F (149°C). Also known as thermal photography.

(medicine)

A medical imaging technique based on detection of heat emitted by the body.