Posted February 27 2015 in Science and 0 comments

Development of thermal imaging in Ukraine

 

Development of thermal imaging in Ukraine

Throughout the history of man has sought to perfect: fly like a bird to sink into the abyss of the ocean like a fish and see in the dark like a cat.

The history of the thermal imagers with a sensitivity in the infrared region of the spectrum based on pyroelectric materials through the study of electric fields in crystals at the change in temperature. The first mention of the pyroelectric effect is contained in the notes Teofrastusa dating from 314 BC. e., who noted that when heated tourmaline crystals attract straws and ash particles. The study of these properties of tourmaline were extended in 1707 by Johann Georg Schmidt Epinusom continue in 1756.

However, some authors considered the beginning of thermal imaging discovery in 1800 by William Herschel thermal radiation outside the visible radiation. By passing visible light through the prism dysperhyruyuchu, Herschel discovered a thermometer invisible heat radiation performance. But only in 1881 by William Abneyem first introduced the concept of "infrared" and it took almost 50 years to use the said infrared light outside research laboratories.

In addition, despite the fact that the phenomenon of the photoelectric effect was known in the late 19th century, intensive work in the field of photovoltaic optical instruments relating to 1920-1930.

The first imager find evaporohraf (1920), which is a thin piece of paper with an alcohol (oil, camphor), one side of which is covered with soot, given the thermal image of the object. Due to uneven evaporation of the alcohol formed visible thermal image. During the Second World War in Germany and the US were created evaporohrafiv improved variants that are attributed to the class neskaniruyuchyh thermal imagers with thermal separation ΔT = 1 о and frame rate f = 0,01 ... 0,1 Hz.

Does not include scanning thermal imagers and edzheohrafy, the operation of which is the shift of the spectral boundary absorption coefficient depending on the temperature. If selenium pass through the film monochromatic radiation, which corresponds to the limits absorption intensity of light passed will depend on the temperature of the film. These edzheohrafy had the following characteristics: ΔТ = 10 оС, the spatial separation of 2 mm-1 and frame rate f = 50 Hz.


By: prof. Bogorosh A.T. (21.12.14)

 




Post Comment

Please Login to Post a Comment.
No Comments have been Posted.
Rating is available to Members only. Please visit page Login or Register to vote.
Awesome! ()0 %
Very Good ()0 %
Good ()0 %
Average ()0 %
Poor ()0 %