Anemometer

Claim 1

An anemometer for flow measuring, in particular for determining an air quantity flowing through a passage of an internal combustion engine, having a block-shaped substrate consisting of glass material of low thermal conductivity arranged in the passage, and said substrate having at least one edge area having a side face parallel with a flow direction facing a holding device for the substrate, having on at least one surface of the substrate a temperature-dependent resistor material covering substantially the entire area of the substrate as well as connecting means for conducting electricity to said surface resistor material, wherein the resistor material forming an area of square resistance is divided into a meander shaped area with surface F w and into said edge area with surface F Rges , said meander shaped area comprising essentially the whole resistance value of said square resistance being heated and supplying a temperature-dependent signal enabling conclusions about the flow measurement, said edge area running parallel with said flow direction having essentially no contribution to square resistance value to be measured, the proportion of the surface F w to the surface F Rges is approximately 1/1<F w /F Rges <3/1, and wherein the length L and the width B are considerably greater than the thickness D of the substrate.