The Launch Tech USA Thermal Imager reads thousands of infrared temperature spots over a surface area and combines those colored heat signals with an image of the object to make a thermal image. The Thermal Imager shows high temperature, low temperature, central temperature, and a heat color code. It measures temperatures from -4 to 842 degrees F with a +/- two percent accuracy. The unit can store up to 20,000 pictures and offers auto shut down.