TEL-FAST thermometers are hand-held, battery-operated devices that safely and accurately measure temperature using non-contact infrared technology. Infrared sensors consist of optics, detector, display, and output. Special optics gather infrared energy from a target and focus this energy onto a custom detector. The detector converts the infrared energy into an electrical signal proportionate to the temperature of the target surface being measured and is displayed as a digital temperature measurement in °F or °C within milliseconds. Tel-Fast non-contact infrared thermometers are ideal for food preparation, automotive, science, electronics, plant maintenance, construction, and HVAC markets.