Fluke 62 MAX Infrared Thermometer 10:1 Spot Ratio

When a transmission is running hot you need numbers, not a hand on the pan. This is Fluke's 62 MAX, a non-contact infrared thermometer that reads surface temperature from a safe distance so you can check a pan, a cooler line, a converter snout or a hot bearing while the vehicle is running and the driveshaft is turning. Range is -22 to 932 degrees F (-30 to 500 C) with accuracy of 1.5 C or 1.5 percent of reading, whichever is greater.

On a transmission job the useful trick is comparing the two cooler lines at the radiator or the auxiliary cooler. Shoot the line going out of the case, then the line coming back. On a healthy system the return line reads meaningfully cooler; if both lines read the same, the cooler is plugged or bypassing and you are about to cook a fresh rebuild. The same check on the pan versus the engine block tells you whether the converter is slipping and dumping heat into the fluid instead of putting it to the wheels. Min, Max, Average and Difference modes hold the readings so you can compare two spots without writing anything down, and adjustable emissivity (0.10 to 1.00) lets you get an honest reading off bare aluminum and polished steel, which fool fixed-emissivity guns.

The 10:1 distance-to-spot ratio means at ten inches away you are measuring a one inch circle, so you can target a single line fitting rather than averaging half the tunnel. Single laser sighting shows where that spot lands. The housing is IP54 rated against dust and splashed fluid and it is drop tested to 3 meters, which is what separates it from the plastic guns that quit after they roll off the bench. Runs on one AA battery, roughly 10 hours with the laser and backlight on, and carries a 3 year warranty. Note this is an industrial instrument and is not for measuring human body temperature.