Thermal Infrared Cameras : The Story

Thermal cameras are able to detect for heat patterns in the infrared wavelength spectrum and rely on the emission of thermal or infrared energy by all objects above 0 Kelvin. Thermography is the use of an infrared imaging and measurement camera to "see" and "measure" thermal energy emitted from an object. This is called "Thermal Imaging. Thermal energy is light that is not visible by the human eye. It is the part of the electromagnetic spectrum that we perceive as heat. Unlike visible light, in the infrared world, everything with a temperature above absolute zero emits heat. Even extremely cold objects emit infrared. Infrared allows us to see what our eyes cannot. Thermal infrared cameras are an extremely valuable diagnostic tool in many applications.

Almost everything that uses or transmits power gets hot before it fails. Thermal imagery allows the maintenance and reliability of electrical and mechanical systems. It is one of the most effective and proven predictive maintenance technology. It allows for safe and accurate troubleshooting. Finding a poor electrical connection before a component fails can save a lot of money by protecting against production losses, power outages, fires and catastrophic failures. It is extremely important to also have accurate measurements when using an infrared camera. An infrared survey without a simple fast way to report and analyze inspection results will not assist in locating problems.

There are many potential uses for thermal imagery as the cameras can detect hidden problems and make quick damage assessments. They can help avoid electrical failures, and check for overheating of electrical panels and transformers. These cameras will find problems with motors, fans and bearings, as well as identify faults in heating and cooling systems. Most of the cameras will generate reports, analyze and document findings with easy-to-use software. The widespread application possibilities make this tool extremely important for many working industries.

How do Infrared Cameras Work?
Infrared cameras detect infrared energy and convert it to an electronic signal. This signal is then processed to produce a thermal image on a video monitor and perform temperature calculations. The heat that is sensed by the camera can be measured and quantified, allowing the identification and evaluation of the severity of heat-related problems. Thermal performance can also be monitored. Detector technology and other recent innovations allows extremely cost-effective thermal analysis solutions. The incorporation of built-in visual imaging, automatic functionality, and infrared software development are components of these innovations.

Why measure temperature?
Infrared cameras with temperature measurement allow maintenance professionals to make informed judgments about the operating condition of electrical and mechanical targets. An infrared camera image without having accurate temperature measurements will not give enough information about the electrical connection's condition. Worn mechanical parts will also not be easily identified. An infrared image without accurate measurement can often be misleading because it can indicate a non-existent problem. Using temperature measurements in conjunction with previous operating temperatures can assist in determining if a significant temperature increase will compromise reliability or safety.

History of Infrared Technology and Thermal Imagers
The discovery of the infrared spectrum came in 1800 by Sir William Herschel. He was an astronomer and built his own telescopes. Equipped with knowledge that sunlight was made up of all the colors of the spectrum, and that it was also a source of heat, he wanted to find out which color(s) were responsible for heating objects. Herschel conducted an experiment using thermometers with blackened bulbs, a prism and paperboard. He measured the temperatures of the different colors and observed an increase in temperature as he moved the thermometer from violet to red. He found the hottest temperature occurred beyond red light. The heating caused by this radiation was not visible. Herschel named this invisible radiation "calorific rays" which we now call infrared.