A.W.T.'s Hot Spot Temperature Sensor Gun is a low cost electronic device used for verifying and monitoring dryer temperature. Use it to locate and control heat buildup in the substrate, potential electrical system failures or possible overheating. Excellent for use in critical heat sensitive applications, such as textile and UV curing, or wherever maintaining temperature is important. Powered by a universal 9 volt battery, it measures from 0 to 780° F ( or 18 to 400° C ) in less than one second.