Incorporates laser pointer for maximum accuracy. Can be used in Celsius or Fahrenheit scale. The distance / diameter measurement ratio is 12:1. The measurement response time is ≤0.5 seconds. Its temperature range is from 34°C to 43°C. The instrument incorporates a backlit LCD display and "auto power off" functions to maximize the life of the 9-volt battery. It is recommended for storage and use at ambient temperatures in the range of 0 to 40°C and a relative humidity of 10 to 95%RH. The emissivity of this instrument is adjustable ensuring accurate measurements on any type of surface.