Basic Knowledge

Measurement accuracy indicates the difference between the measured temperature and actual temperature. The smaller the value, the better the performance of infrared thermal imager.

IFOV also called as spatial resolution. It indicates the actual size of the corresponding objects for each pixel, expressed in radian. The smaller the IFOV, the higher the imaging resolution.

In the case of optical devices, set optical instrument’s lens as vertex, the angle formed by two edges of the maximum range that the image of the measured objects can pass through called FOV (Filed of view). With the same resolution, the larger the FOV, the wider the range of observed objects, but more blurred the images.

Temperature compensation technology is used to weaken or eliminate the measurement error caused by ambient temperature changes. Its principle is calculating the changes of sensor’s temperature emissivity, ambient temperature, etc. values to correct the measurement data.

Technology that converting object surface’s temperature distribution into a visible image through the special electronic equipment and displaying the temperature distribution in different colors called thermal imaging technology.

All objects above absolute zero (-273℃) emit infrared radiation. Find and recognize targets by using infrared radiation images formed by radiation differences between objects.

Infrared thermal imagers are usually composed of infrared detector/refrigerator unit, infrared optical lens, optical unit, focusing/magnifying unit, internal non-uniformity correction unit, imaging circuit unit, etc.

Infrared thermal cameras are one of the devices that support to collect infrared radiation (heat energy) and convert them into a visual image with temperature data.

Infrared Detector is the heart of thermal camera devices. Its main feature is to convert infrared radiation into electrical signal. Infrared detector can be divided into cooled and uncooled detectors.

Cooled detector: Based on photovoltaic detector and photon detection, integrated cryogenic cooler is used to cool down the detector. Its purpose is to make the thermal noise signal lower than the imaging signal. Cooled detectors are commonly used in military applications (e.g., Space equipment, Warships, etc.).

• Advantages: High sensitivity, high accuracy, long detection distance, fast response time, and stable performance.
• Disadvantages: Large power consumption, high-cost, low flexibility.

Uncooled detector: Based on microbolometer & thermal detection, uncooled detector mainly includes polysilicon and vanadium oxide, which is usually used in civilian field (e.g., Circuit inspection, equipment maintenance, etc.)

• Advantages: Low power consumption, low-cost, high flexibility.
• Disadvantages: Low sensitivity, slow response time, short detection distance.