Sir William Herschel, an astronomer, discovered infrared in 1800. He built his own telescopes and was therefore very familiar with lenses and mirrors. Knowing that sunlight was made up of all the colors of the spectrum, and that it was also a source of heat, Herschel wanted to find out which color(s) were responsible for heating objects. He devised an experiment using a prism, paperboard, and thermometers with blackened bulbs where he measured the temperatures of the different colors.
Herschel observed an increase in temperature as he moved the thermometer from violet to red in the rainbow created by sunlight passing through the prism. He found that the hottest temperature was actually beyond red light. The radiation causing this heating was not visible; Herschel termed this invisible radiation "calorific rays." Today, we know it as infrared.
Infrared Thermography is the technique that uses an infrared imaging and measurement camera to "see" and "measure" invisible infrared energy being emitted from an object.
Thermal, or infrared energy, is energy not visible because its wavelength is too long for the sensors in our eyes to detect. It is the part of the electromagnetic spectrum that we perceive as heat. Unlike visible light, in the infrared spectrum, everything with a temperature above absolute zero emits infrared electromagnetic energy. Even cold objects such as ice cubes, emit infrared radiation. The higher the temperature of the object, the greater the infrared radiation emitted. An Infrared camera allows us to see what our eyes cannot!
In the industrial/commercial environment, almost everything gets hotter or cooler before it fails, making infrared technology an extremely valuable diagnostic tool with many diverse applications. And as industries strive to improve manufacturing efficiencies, manage energy, improve product quality, and enhance worker safety, new applications for infrared technology continually emerge.
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How Does an Infrared Camera “See” Heat?
All objects, cold or hot, radiate heat in the form of infrared energy. As an object increases in temperature, it radiates more energy, and the wavelength gets shorter. Infrared radiation, visible light and ultraviolet light are all forms of energy in the electromagnetic spectrum. The only difference is their wavelength or frequency.
The human eye can only see a narrow range of wavelength in the electromagnetic spectrum. These wavelengths range in length from 0.4 to 0.7 microns, a micron is one millionth of a meter. Most of what the eye sees is reflections from objects that high energy from the sun or an incandescent light bulb is striking. If the temperature of an object gets hot enough however, above 525°C, the energy from that object will radiate energy in the visible spectrum and we will see it. This is when we see an object like the burner on an electric stove “glowing” red. In fact, any time an object will emit or reflect energy in the same frequency of our eyes we will see it. Mostly, however we see reflections!
The Electromagnetic Spectrum
Infrared Inspections are Simple, Right?
Taking thermal images and gathering thermal information is quite easy these days, just push the auto button and there is an image! However, this may seem simple on the surface, but it is not as easy as it sounds. The real work — and value — is what the Thermographer understands about the object of interest, how it operates, the heat transfer within and to the surface of the object, how to adjust the camera to enhance the thermal details necessary to evaluate the image once it is stored and downloaded onto the computer. Then prepare a report that is accurate, clearly presented and is easy to read by the end user, who generally does not know anything about infrared Thermography. As in any method of nondestructive testing, the interpretation of the information gathered takes both education and experience. Richardson Building Diagnostics has the experience to provide you with the “solutions” you’re looking for.
WHY USE INFRARED?
A picture says a thousand words; infrared Thermography is the only diagnostic technology that lets you instantly visualize and verify thermal performance. Our infrared camera can show you thermal problems, quantify them with precise non-contact temperature measurement, and document them automatically in seconds with professional easy-to-create IR reports. Nearly everything that uses or transmits power gets hot before it fails. Cost effective power management is critical to maintaining the reliability of your electrical and mechanical systems. And today, no one would argue that infrared Thermography is the most effective proven predictive maintenance (PM) technology available to quickly, accurately and safely locate problems prior to failure.
In June 2005, Maintenance Technology magazine reported a $4 return on investment in for every $1 spent on infrared inspection. Finding and fixing a poor electrical connection before a component fails can save you the much greater costs associated with manufacturing downtime, production losses, power outages, fires and catastrophic failures.
But using infrared images to find a problem is sometimes not enough. In fact, an infrared camera image without an accurate measurement says very little about the condition of an electrical connection or worn mechanical part. And, an IR survey without a simple, fast way to report and analyze inspection results provides no ability to make timely repair decisions or locate and separate those 'hot spots' that can cause problems from those associated with equipment operating normally. Our infrared camera not only quickly locate problems, but coupled with Reporter software, its non-contact precision temperature measurement and analysis capabilities instantly deliver the answers you need to understand what repair action to take, and when.
