Infrared thermography is the science of detecting thermal energy emitted from an object, converting it to apparent temperature, and displaying the result as an infrared image. With an infrared camera you can capture thermal images without making direct contact with equipment. That means you can capture thermal information from operating equipment at a safe distance and have a better chance of seeing temperature anomalies under normal operating conditions. Most popular infrared cameras capture radiometric thermal images, that contain apparent temperature measurements for each pixel within the image. With that capability, you can identify an anomaly and then drill down to calculate the apparent temperatures of the points in question.
The non-contact nature of infrared thermography makes it ideal for a wide range of applications where components are moving, very hot, dangerous to contact, difficult to reach, impossible to shut off, or could be contaminated or damaged through contact. Infrared cameras are also very helpful in detecting energy or moisture-related problems in a building envelope.