Mäntämittari

Mäntämittari is a Finnish term that translates to "piston gauge" or "plunger gauge" in English. It refers to a measuring instrument used to determine the dimensions or tolerances of cylindrical components, particularly pistons, and their corresponding cylinders. This type of gauge is essential in precision engineering and manufacturing, especially in industries like automotive and aerospace, where tight tolerances are critical for optimal performance and longevity.

The mäntämittari typically consists of a frame or body that holds adjustable measuring anvils or contacts. These contacts are designed to be brought into contact with the surface of the piston or the inner diameter of the cylinder. The gauge often incorporates a dial indicator or a digital readout to display the precise measurement. Variations exist, including go/no-go gauges for quick checks and more sophisticated instruments capable of measuring taper, ovality, and other geometric deviations.

The primary function of a mäntämittari is to ensure that the fit between a piston and its cylinder is within specified limits. An excessively loose fit can lead to reduced compression, increased oil consumption, and engine noise. Conversely, a fit that is too tight can cause friction, overheating, and premature wear. Therefore, using a mäntämittari is a crucial step in quality control during the manufacturing process and for maintenance and repair operations.