What is infrared thermal imager?

Infrared thermal imager is a device that uses
infrared thermal imaging technology to convert the image of the temperature distribution of the subject into a visual image by detecting the infrared radiation of the subject and converting it to signal processing, photoelectric conversion, and other means.
Infrared thermal imaging camera will detect the heat for accurate quantification, in the form of surface imaging of the subject matter in real-time as a whole, so it can accurately identify the suspected fault areas that are heating up. The operator uses the image color displayed on the screen and the hot spot tracking display function to initially identify heat generation and fault areas while performing rigorous analysis, thus demonstrating high efficiency and accuracy in identifying problems.
Thermal imaging cameras, which were earlier used in the military field, have been expanding into civilian and industrial applications over the years. Some developed countries in Europe and America have started to explore the use of thermal imaging cameras in various fields since the 1970s. After decades of continuous development, the thermal imaging camera has evolved from a bulky machine to a lightweight and portable device for field testing.
Working principle of infrared thermal imager
Infrared thermal imager is the science of using optoelectronic devices to detect and measure radiation and to establish a correlation between radiation and surface temperature. Radiation is the movement of heat that occurs when radiant energy (electromagnetic waves) moves without a direct conduction medium.
Modern thermal imaging cameras are practical instruments that use optoelectronic devices to detect and measure radiation and to establish a correlation between radiation and surface temperature since all objects above absolute zero (-273°C) emit infrared radiation.
Infrared thermal imaging camera uses an infrared detector and optical imaging objective lens to accept the infrared radiation energy distribution pattern of the measured target reflected by the infrared detector's photosensitive element, to obtain an infrared
thermal image map. This thermal image corresponds to the heat distribution field of the object’s surface. In layman's terms, an infrared camera is a camera that transforms the invisible infrared energy emitted by an object into a visible thermal image. The different colors on the thermal image represent the different temperatures of the object being measured. By viewing the thermal images, the overall temperature distribution of the target under test and the heat generation of the target under study can be observed to make a judgment on the next step.
Thermal imaging advantages
a.
Infrared thermography is a technology for passive, non-contact detection and identification of targets. It has the characteristics of good concealment and is not easy to be discovered, thus making the infrared thermal imager operator safer and more effective.
b.
Infrared thermal imaging technology has a high detection capability and a long range of action.
c.
Infrared thermal imaging technology truly does 24h all-weather monitoring. As infrared radiation is the most widespread radiation in nature, the atmosphere and smoke clouds can absorb visible light and near-infrared light, but they cannot absorb the infrared radiation of 3~5μm and 8~14μ because they are transparent. These two transparent wavelengths are called the "atmospheric window" of infrared. Therefore, using these two windows, you can observe the target you need to monitor at night when there is no light at all, or in a harsh environment of rain, snow, and other dense smoke and clouds. It is because of this feature that infrared thermal imaging technology can truly do 24 hours day surveillance.
d. Infrared thermal imaging technology can visually display the temperature field on the surface of an object without being affected by bright light and can be monitored in the presence of obstructions such as trees and grass. Infrared thermometer can only display the temperature value of a small area or a point on the surface of the object, while
infrared thermal imager can simultaneously measure the temperature level of each point on the surface of the object, visually display the temperature field of the object surface and display it in the form of an image. Infrared thermal imager is an instrument that detects the magnitude of infrared thermal radiation energy of the target object, unlike a micro-light-like intensifier that will appear as a halo or turn off when in a bright light environment, so it is not affected by bright light.
Application of infrared thermal imager
a. Monitor the generator and motor for unbalanced load, high bearing temperature, carbon brush, slip ring and collector ring heating, short circuit or open circuit of winding, blocked cooling line, overload overheating and other problems.
b. It can be used for maintenance and inspection of electrical equipment. And it is also more helpful for safety and theft prevention, roof leak detection, environmental protection inspection, energy-saving inspection, non-destructive testing, forest fire prevention, medical inspection, quality control, etc.
c. It can monitor sudden natural environmental changes like volcanic eruptions, landslides, etc.
d. Monitor the transformer for bushing overheating, overload, loose joints, poor cooling tube blockage, poor contact, unbalanced three-phase load, etc.
e. Monitor electrical devices for poor contact, overload, loose joints, overheating, unbalanced loads, and other hidden dangers.
The application of infrared thermal imagers is becoming more and more extensive, it plays a pivotal role in the field of scientific research, medical field, electronics, and other industries.
Performance parameters of infrared thermal imager
Thermal camera
A. Detector resolution
Detector resolution is the number of pixel points in a thermal image. Higher resolution means more temperature measurement points, smaller targets that can be measured and longer distances that can be observed. Usually, thermal imaging cameras can provide the conventional resolution of 160 * 120, 400 * 300, 640 * 480, 800 * 600.
The advantages of using a larger resolution of the thermal imaging camera with a larger surface array are as follows.
a. Increase the effective pixel count, allowing for more detail.
b. Obtain wider field of view for more coverage area with the same focal length lens.
c. Make the video output present better visual effect.

B. Focal length/field of view/spatial resolution
According to the observed target object size, and distance, the need to observe the range and details to select a different lens configuration, so as to obtain different spatial resolutions.
C. Thermal sensitivity
Thermal sensitivity is also known as NETD (Noise Equivalent Temperature Difference). The noise equivalent temperature difference of thermal sensitivity is the smallest temperature that the thermal imaging camera can distinguish. The smaller the NETD, the higher the thermal sensitivity. This indicates that the less noise in the output IR image, the finer the thermal imaging camera can detect temperature changes.
The advantages of using a smaller NETD detector are as follows.
a. Better target background recognition.
b. Clearer and more legible target details.
c. More flexible choice of matching optics: F/1.0, F/1.2, F/1.4.
d. Smaller system size.
e. Better overall system cost.
D. Temperature range/accuracy
The user can choose the appropriate thermal imaging camera temperature range and accuracy according to the temperature range of the object to be measured. Temperature measurement accuracy is the error between the measured temperature value and the absolute temperature. General industrial-grade thermal imaging camera temperature measurement accuracy is ± 2 degrees Celsius or ± 2% (the greater of the two values).
E. Frame Rate
Frame rate is the number of frames per second that a thermal imaging camera produces a complete image. If the object to be measured is moving very fast or the temperature is changing quickly, an infrared camera with a higher frame rate should be used. Otherwise, the measurement accuracy will be affected. The frame rate of some products may be set to 9 Hz due to export restrictions. And the domestic thermal imaging camera can reach there are 50 hertz or even higher.
Use of infrared thermal imager

Infrared thermography
A. Adjust the focal length
Thermal imaging camera applications affect the accuracy of the target temperature measurement if the background temperature around the measured target is too cold or too hot. And in general, the thermal imaging camera application can be adjusted after the thermal image is stored on its curve, but it cannot change the focal length after the image is stored, and there is no way to eliminate other heat reflections. Therefore, the focus or measurement orientation needs to be adjusted to reduce or eliminate these effects.
B. Choose the right temperature range
The temperature range is one of the most important performance indicators for thermal imaging camera applications because thermal imaging cameras are used to detect images by measuring the temperature of the target, which means that the temperature range should be neither too narrow nor too wide. It is important to note that the temperature range of the camera should be slightly adjusted to match the measured target temperature as closely as possible before applying the temperature measurement in order to obtain the best image quality.
C. Knowing the maximum detection distance
In fact, the maximum detectable distance is not a fixed figure but is related to the size of the target and the performance of the infrared detector. If you use the same thermal imaging camera to measure a relatively large area of the target, then the detectable distance is farther, and vice versa. Therefore, when detecting certain smaller targets, it is important to choose the right thermal imaging camera to ensure that the temperature is detected at an effective distance to prevent inaccurate data. And in the detection, thermal imaging camera applications need to maintain a moderate distance from the target.
D. Keep the instrument smooth
When pressing the store button, you should be careful not to shake the thermal camera too much to ensure that the images are accurate and not blurred. Or you can support the instrument with a tripod to make the instrument more stable.
E. Single detection environment
Due to the distribution of the measured target, the working environment of the thermal imaging camera application is often outdoors, and then it is easily affected by weather factors. Of course, the atmospheric environment is unchangeable, so you can also make moderate adjustments in advance according to the environmental characteristics to ensure the accuracy of the measurement data. In addition, you can also try to choose no rain, no fog, no sunlight or in the night, no wind or low wind environment, so that there are no impurities or few impurities around to avoid excess reflection.
How to buy infrared thermal imager?
ANTITECK provide lab equipment, lab consumable, manufacturing equipment in life sciences sector. If you are interested in our infrared thermal imager or have any questions, please write an e-mail to info@antiteck.com, we will reply to you as soon as possible.