New from Pacific Sensor Technologies the Model 6130.4ZH an 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.
A 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, cannot be ascertained by the operator.
It is 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 (Thru-The-Lens) Intra-Optical Light Sighting System 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.
An accurate temperature reading can be made only if the target completely fills the field of view (FOV) of the instrument. With the Vario-Zooom Focus, 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.
In 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 can 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 the connector.
All of this is true only if the target’s surface is perpendicular to the centre line of the FOV. If the target’s surface is tilted at an angle to the FOV Centre 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.
This three-dimensional TTL/SLR 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.
Key features include:
- Vario-zooom focus
- TTL/SLR intra-optical light sighting using LED (US Patent No. 4,477,814)
- Field of view continuously variable from 2 degrees to 15 degrees
- Select to measure the IR temperature, the ambient air temperature or the differential between the two (US Patent No. 4,301,682)