Three distinct, patented, systems make Everest Interscience’s infrared thermometers unique for taking accurate temperature measurements outdoors.  These include the following:  a SKY-SPY™ System (U. S. Patent No. 4,420,465), VARIO-ZOOOM™ Field-Variable-Focus System (U. S. Patent No. 7,355,178), and TTL/SLR Intra-Optical Light Sighting System (U. S. Patent No. 4,494,881).  These features combined provide for the most accurate possible infrared thermometers for measurements of outdoor targets. 

SKY-SPY™ System
You may have noticed that some of your outdoor infrared thermometer measurements have been inconsistent and non-repeatable under apparently identical conditions. There is a reason for these errors.  When an infrared thermometer is calibrated indoors, it will be off by 1-2
°C when used outdoors.  This is because the cold sky reflects off of the target’s surface and into the thermometer.  This reflection combines with the target’s radiation signal causing an error.  This error is dynamic and unpredictable and can vary from 0.5°C to 2.0°C in a matter of minutes, making reproducible readings impossible.   

The SKY-SPY™ System “...provides a novel means for sensing the level of infrared radiation received by the vegetation from a skyward direction,” according to U. S. Patent No. 4,420,265.  With this invention, a second wide-angle optical system and detector are utilized wherein the reflection off of the surfaces received from a skyward direction may be taken into account to measure the “true” surface temperature of the target and not the “apparent” temperature, thereby reducing inaccuracies caused by sky radiation. 

 VARIO-ZOOOM™ Field-Variable-Focus Infrared Thermometry System
This new Field-Variable-Focus Infrared Thermometry System provides the first infrared thermometry system capable of both varying the focus and field view of the infrared thermometer to identify the exact target area where a surface temperature measurement is being taken. 

For the life of the infrared industry, it has been necessary to be sure to match the infrared thermometer to the application.  If a person wanted to measure a very minute target, it was necessary to purchase a close-focus instrument.  For targets at a greater distance, an infinity focus infrared thermometer was needed.  With the invention of the VARIO-ZOOOM™, the Field-Variable-Focus Infrared Thermometry System, this is no longer necessary. 

One infrared thermometer can be used for both applications referred to above.  The focus can be easily changed simply by gently pushing the optics of the instrument in or pulling it out.  After finding the optimum focus, the operator can lock it into place on the infrared sensors.  The instrument will remain focused at that distance until it is refocused.  There is no lock on the handheld units, but two rubber gaskets stop the optics from moving after the unit is focused.

When focusing in the laboratory, the next feature, the TTL/SLR Intra-Optical Light Sighting System, assists in adjusting the variable field of view.

TTL/SLR Intra-Optical Light Sighting System
The Through-The-Lens/Single Lens Reflex Intra-Optical Light Sighting System provides a means for the end user of an infrared thermometer to ascertain exactly where a temperature measurement is being taken.   With this system, a light shares the same path as the infrared optics and illuminates the exact target being measured.  The source of this light is a safe Light Emitting Diode. 

This invention arose from a long-time need in the field of infrared thermometry.  Other conventional infrared thermometers have been unable to precisely align the infrared sensor on the target and identify the exact target area being measured.  And, it is well known in the infrared industry that infrared surface temperature measurement reading errors can result from improper alignment of the infrared thermometer with the target.

When the optical system of the infrared thermometer is not pointing directly at the target, the detector collects energy coming from the target and the background, thereby providing an erroneous reading.  What’s more, since the infrared beam is not visible to the human eye, the alignment of the IRT with the target cannot be visually controlled with conventional infrared sensors.

With this system, the exact location and dimensions of the target area under test are precisely identified.  This is true not only under static conditions, but also under variable imaging conditions which may result when re-focusing the Field-Variable-Focus infrared sensor.

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