Digital thermometer for measuring temperature in heating, ventilation, and air conditioning applications, including refrigeration and heating systems, supply and return registers, circuit breaker panels, motors and bearings, transformers, and ducts * Measures temperature from -33 to 220 degrees C (-27 to 428 degrees F), with an accuracy of + or - 2 degrees C (4 degrees F) * Infrared sensor measures temperature from a distance * 1:1 distance-to-spot ratio * Adjustable emissivity helps improve measurement accuracy on a range of surface types