optris Xi 400, Operator'S Manual

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HFOV : Horizontal enlargement of the total measuring at object level
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VFOV : Vertical enlargement of the total measuring at object level
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IFOV : Size at the single pixel at object level
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DFOV : Diagonal dimension of the total measuring field at object level
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MFOV : Recommended, smallest measured object size of 3 x 3 pixel
(Xi 400/410) and 2 x 2 pixel (Xi 80)
Geometric resolution for ideal temperature measurement
When designing optics for measuring IR cameras, special attention must be paid to the quality of detail
contrast with which an object can be represented in the image. This is described by the modulation transfer
function (MTF). Since in contrast to visual cameras, with IR cameras the thermal contrast is of more interest,
this is used together with the slit response function (SRF). The result is determined by the number of pixels
an object needs to fill to allow its temperature to be measured exactly. In high-performance infrared optical
systems as used by Optris, this is
3×3 pixels or 2x2 pixels , with lower quality optical systems, in some
circumstances as many as 10×10 pixels may be required, to receive 90 % of the energy. A high-performance