Do you know the three key points of shooting infrared thermal image correctly?


As we all know, accuracy is the key when using thermal imaging cameras for detection and data acquisition. Whether you are an experienced infrared thermal imaging engineer or a beginner, Gao Dezhi Sense wants to tell you the secrets of correct detection, let's talk about it in detail below!

Generally, after the thermal image is stored, the following three elements cannot be modified: optical focus, temperature measurement range, and shooting distance. The next time you perform infrared inspections, you must remember these three key points to ensure that the image can be analyzed correctly: the thermal imager must be aimed at the focal plane, taken within the correct temperature range, and taken from the appropriate distance.

Although some parameters such as thermal adjustment and color palette can be adjusted and processed by software, the parameters cannot be changed easily. Therefore, obtaining the correct parameters is the key before saving any infrared image.

Optical focus-"FO"

You need to focus carefully before storing the thermal image, just like with any camera, before taking the image, you must optically focus it to avoid blurring the image. In order to avoid inaccurate temperature measurement values, before taking any infrared images, be sure to carefully check the focus of the thermal imager to get the best focus from the lens to the measured object, because this cannot be corrected after saving the image.

Simply put, accurate focus = better measurement.

Temperature measurement range-"R"

When you want to measure an object with a thermal imaging camera, you must first know whether it is within the temperature measurement range of the thermal imaging camera. Although many thermal imaging cameras claim to be able to detect and measure objects in the temperature range of -20°C to 1500°C, they cannot be done within the temperature range of a single image.

Therefore, most modern infrared thermal imaging cameras decompose the total temperature measurement specification into a number of specified temperature ranges, covering the temperature interval at which the detector can see the image without exceeding the range. When saving an image, all data within a specific range will be captured. Therefore, it is important to stay in the correct temperature range before saving the image.

Shooting distance-"D"

Always make sure you keep a proper distance from the target. In the example above, the distance is 1.5 meters. Through the resolution, the thermal detail area on the object can be distinguished, and enough information can be captured to accurately measure the temperature.

An infrared image is composed of pixels, which are a single detector unit that senses infrared radiation. All thermal imaging cameras are restricted to resolve targets of a certain size at a certain distance. Under certain other conditions, the resolution is a function of the number of detector units in the thermal imager and the lens size or the field of view (FOV) of the thermal imager lens. Make sure you are close enough to the target to use as many detector units as possible to image the target to obtain the best resolution of the target imaging. If you are taking temperature measurements, a good rule of thumb is to completely fill the center ring on the measuring tool with the object to be measured to ensure that you get the most accurate readings at the right distance.

If you work hard, but you still can't completely fill the center ring with the measured object, and you have been as close as possible to a safe distance. At this time, you may wish to switch to a telephoto lens, which is also a good choice to improve accuracy!