Hey badmusttang, I look at the volt meter, great price, only thing, do a I still need to buy the magnetic thermocouple, I couldn't tell if it came with the meter, and if not, where can I get one.
IR Guns are difficult to get accurate readings. They work on the principle of emisstivity - or a measuring of the wave length of the hot part. They are calibrated against a perfect, flat, black body. Therefore many things can affect the readings, like, shiny parts, color, round surfaces, etc.
Very true, if you plan to use one to, lets say double check your tranny or rear diff. you should paint a location with flat black paint, and hold the gun a right angle.
I forgot to mention also the material will affect the reading. . Try and measure ir on steel or cast iron. Not aluminum.