Sper Scientific IR thermometer can quickly and accurately determine the (surface) temperature of the target by measuring the infrared energy radiated by the surface. This 12:1 D/S ratio unit is suitable for non-contact temperature measurement and has a range of -58°F ~ +932°F. Simply hold the IR gun, air the laser guide at the target and press the trigger to read temperature in °F/°C. Emissivity is set to 0.95 but can be adjusted (0.1 to 1.0) based on target surface ratings. Other functions include temperature alarm (high/low) and auto power off (15 seconds).