The Dwyer IR3 / IR4 Infrared Temperature Thermometers utilize infrared technology for precise, non-contact temperature measurement. For standard applications, the 12:1 distance to target ratio on the IR3 provides accurate measurements within 2% of reading. When measuring smaller objects or at greater distances, the 20:1 distance to target ratio of the IR4 can provide measurements within 1% of reading. Both models have single point laser sighting for aligning the beam to the target. In addition, both models can display maximum, minimum, differential and average temperature measurements. Adjustable emissivity allows the thermometers to measure the temperature of most surfaces without any external calculations. A K-type thermocouple can plug into the handle of the thermometers in order to take surface and internal temperatures simultaneously. Audible alarms can be used to for safety checks.