The vortex flow meter provides a surface which is simple but nevertheless resistant to the substances to be measured. Adjustment of the gain is performed by determining a peak voltage between a gain stage and a dummy gain stage amplifier that does not amplify the input voltage. A weld region, where the ground electrode is joined to the metal shell, has an undulating shape. One element of the front mounted gearset is secured to a gearbox housing. By carefully choosing the design parameters of a liquid crystal display, it is possible to obtain vivid colors from the display as a function of the operating voltage.