| The most common automotive use for an infrared pyrometer is probably measuring tire temperatures when setting up a chassis, which is one of the necessary pieces of information that allows an enthusiast to see the effects of alignment and tire pressure changes, and to know quickly which way to go. Here, we are using the MiniTemp MT4 to set tire pressures while skidpadding a tuner car. Thanks to this tool, we found out these tires tend to want a lot of pressure, and their traction falls off significantly when they get hot. That is also useful information when driving, because we now know they are intolerant of being overdriven, whereas other tires may take more sliding around.
When pushing the limits of performance of any component, an essential piece of information is temperature. In the good old days, real sports cars came with coolant temperature gauges that read in actual units. My Fiat indicated both Celsius and Fahrenheit, as well as carrying English and Italian labeling. Race cars monitor temperatures everywhere. Differential, transmission, engine oil, sometimes even dampers--basically, anything that gets hot and matters. Systems which monitor many temperatures continuously can be costly, but there are still many times that we, as enthusiasts, would like to check the temperature of a part on our cars.
This month's tool is one of the easiest and fastest ways ec's editors have found to do just that. The Raytek MiniTemp MT4 is an affordable, handheld, infrared pyrometer. It requires no physical contact with a surface and registers the temperature essentially immediately upon triggering. The MiniTemp MT4 has a laser sight, and costs only a little more than the non-laser-equipped MiniTemp MT2.
One fine point to recognize in using the MiniTemp MT4 is that its temperature reading pattern spreads at a 6:1 ratio with sighting distance, i.e., it is an oval 4-in. long when the MiniTemp MT4 is held 24 in. from the target. It is important to remember that even though the laser sight has "laser beam precision," the area of which the surface temperature is being measured is much, much larger. It can be tricky to sight onto a small object deep within an engine compartment.
Other details to keep in mind are that the MiniTemp MT4 measures surface temperature, not bulk temperature, and it can't be used while a car is in motion. The operating temperature of a part such as a brake disc is better determined by another method, such as temperature sensing paint. Given that, we've thought of a ton of uses, and there are certainly thousands more we haven't thought of. Do you want to know how hot that glowing turbo is? How about finding a rich cylinder, or determining the effect of an unbalanced, restricted exhaust manifold design? Shock absorbers can get hot and their performance fall off. There are many things that one might not want to touch on a car. Electrical items are an obvious safety issue, while curing paint and bodywork will be damaged by putting a probe on them. This short list includes just a few uses. We have found the MiniTemp MT4 to be a versatile, easy-to-use, low-cost tool that does what it does very well.