JP2648358B

In the use of an apparatus for measuring air masses in the intake pipe of internal combustion engines, which apparatus as a rule has a plate-shaped carrier body with at least one resistance layer arranged thereon, the problem of dirt deposits on the carrier body end face facing the flow arises, which results in undesired changes in the characteristic line as compared with the calibrated new state of the air mass-measuring instrument. The new design of the air mass-measuring instruments is intended to allow a calibration more suitable in practice. In order to produce the effect of long-term fouling arising in operation on the carrier body (18) of an air mass-measuring instrument even in the new state, a front body (23), which can, for example, have a U-shaped form, is provided on the end face (19), facing the flow (2), of the carrier body (18). A fouling effect, which is also taken into account in the calibration, is simulated by the front body (23) even in the new state of the air mass-measuring instrument. The front body (23) can consist of an electrically conductive plastic or paint and be connected to an earth line (15). The air mass-measuring instrument is quite generally suitable for the measurement of flowing media.