One can imagine, that there are also other adjustment possibilities. Indeed, in this case, it's clear, that with the temperature gauge, the wheel alignment is being checked. What's more, this was done using a contact- thermometer, which after the respective heat transmission, was in fact, only measuring it's own temperature. This type of measurement takes a bit of time because first of all, a heat transfer must take place.
Before we go into other measuring systems, such as length-, volume- or electric changes, we'll move directly to the non-contact measuring carried out by infrared thermometers, which fall into the category of pyrometers. For an extremely brief measuring period of less than 1 second, one utilises the fact that, depending on the temperature, thermal radiation takes place, even at very low temperatures.
A pyrometer collects thermal radiation through an optical system, which bundles it onto a sensor. Infrared light lies directly next to the red in the chromatic spectrum and represents a spectral range of 1 mm to 780 nm. The temperature can be determined by measuring the radiation either over this entire range, or over a smaller, optically filtered range.
Infrared thermometers are particularly suitable, e.g., immediately after spray-painting where the surface cannot be touched or when the object to be measured is so hot that one can't get near enough to it. In the motor car field of course, it is used more often because the area to be measured is not easily accessible. The effective containment of the area to be measured, is difficult in the field of automobile technology.
The measuring is particularly precise, then when the optical system can take up sufficient thermal radiation, i.e., when it's not dirty or partially covered. On the other hand, it should only pick up the radiation from the area to be measured. 03/14
