infrared thermometer measures the temperature of a target surface by focusing a
spot on the target through an optical field-of-view (telescope) onto a
temperature sensitive detector. Infrared radiation is transmitted through the
optics and impinges on the infrared detector surface, heating it slightly.
major shortcoming of infrared thermometers is that the infrared “light”
(radiation) is invisible to the human eye. Therefore, the position and physical
characteristics of the spot being measured, such as its location, shape, size,
surface texture, etc., cannot be ascertained by the operator. It is very
important for the operator to know where all parts of the target spot are
located, because, if any part of the spot is off the edge of the target surface,
serious reading errors will occur.
Everest TTL/SLR Intra-Optical Light Sighting System (U.S. Patent
solves this problem. An illuminated image of the infrared detector is projected
directly through the infrared optics of the infrared temperature sensor,
illuminating the exact area where a temperature measurement is being taken.
Because this light shares the optical path, it can never be knocked out of
alignment. It will always illuminate the area where the optics is focused.
accurate temperature reading can be made only if the target completely fills the
field of view (FOV) of the instrument. With the VARIO-ZOOOM™
Field-Variable-Focus (U.S. Patent No. 7,355,178) the image of the
square detector is projected directly on the target, giving a three-dimensional
image. When the pattern of the detector is square and clear, the infrared
thermometer is in focus. When the image is round and slightly blurred, the
instrument is afocal, or out of focus. If the square pattern is shown on any
area surrounding the intended target, the instrument will be averaging the
temperature of the target and that of the surrounding area being illuminated.
order to focus on a smaller area, the front of the VARIO-ZOOOM™ infrared
temperature sensor need only be rotated until the target is completely
illuminated and the square image is directly on that target. If the target is
smaller than what is being illuminated, that is, if the surrounding area is also
being measured, the sensor must be brought closer to the target in order to
illuminate only the target. Once the target has been determined, then the
instrument can be locked onto that target by turning the knurled ring close to
All of this is true only if the target’s surface is perpendicular to the
center line of the FOV. If the target’s surface is tilted at an angle to the
FOV Center Line, the resulting spot shape is rectangular or oval. The reading
is still quite accurate, but the longitudinal dimension has increased
considerably (+40% at a 45º tilt). It is critical to know if all parts of the
FOV are still within the target confines in order to get an accurate reading.
That can be done simply by noting where the image of the detector is located.
unique three-dimensional TTL/SLR Intra-Optical Light Sighting System projects a
visible image of the infrared detector onto the target surface being measured.
This sighting system shows the exact location, size, shape, texture and focus of
the measurement, thus taking the guesswork out of infrared thermometry.