Advantages of Thermal Imaging | disadvantages of Thermal Imaging
This page covers advantages and disadvantages of Thermal Imaging. It mentions Thermal Imaging advantages or benefits and Thermal Imaging disadvantages or drawbacks. It is useful for thermal imaging camera and other products. The page describes working of thermal imaging camara.
What is Thermal Imaging?
Thermal imaging is non-contact technology which measures infrared wavelengths emitted from objects and converts these temperature information into image. The image features color palette which represents temperature range of different parts of the image displayed. Figure-1 depicts thermal image of machine.
Hot spots or rise in temperature indicates possible problems or failures. Thermal imaging camera and other products work based on the fact that all objects that have a temperature above absolute zero emit heat. These wavelengths are very long and can not be detected by human eye. These parts of electro-magentic spectrum can be perceived as heat and are known as infrared wavelengths. The hotter the object, more is its infrared energy radiation.
How thermal imaging camera works
Let us understand working of thermal imaging camera.
• Infrared energy coming from object is focused by optics onto an infrared detector.
• The detector sends this received information to sensor for image processing using complex algorithms.
• The sensor translates this data into an image which can be viewed on LCD screen of the thermal imaging camera.
• Each pixel of image is measure of temperature at different points. For example if resolution of image by camera is 60 x 60 pixels, then it is equivalent to use of about 3600 Infrared thermometers used simultaneously.
Following specifications are critical in selecting thermal imaging products.
• Temperature range
• Thermal sensitivity or NETD (Noise Equivalent Temperature Difference)
Benefits or advantages of Thermal Imaging
Following are the benefits or advantages of Thermal Imaging:
➨This technology has created more efficient and safer method of measurement.
➨Regular predictive maintenance using thermal imaging products help in saving money and consecutively lower the costs. This is due to less downtime, power outages, production losses, fires etc.
➨Thermal imaging products provide fast and accurate measurements of objects which are difficult to touch/to reach such as high altitude power lines.
➨Thermal imaging allows very accurate temperature measurements of machines from distance and in running condition as shown in the figure-2. This running machines are very hot and dangerous to contact. Moreover it can not be turned off until production is completed.
➨It can help in identifying air leakages, documenting irregular heat dispersion and identifying possible irregularities in insulation.
Drawbacks or disadvantages of Thermal Imaging
Following are the drawbacks or disadvantages of Thermal Imaging:
➨Thermal imaging products require high initial investment cost.
➨Images are difficult to interpret in specific objects having erratic temperatures.
➨Accurate temperature measurements are hindered by differing emissivities and reflections from surfaces.
➨Thermal imaging cameras are not used for study of under water objects.
➨Most of the thermal imaging cameras have +/-2% accuracy or worse for temperature measurement and are not as accurate as contact methods.
➨Thermal imaging cameras can not see through glass as thermal energy can be reflected off shiny surfaces. Moreover these cameras can not see through walls.