Abstract: To measure a wide range of flow rates, and particularly such low flow rates as 0.5 liters per hour, while being able to accurately also measure rates of about 100 liters per hour, fluid is introduced axially into a rotor (14, 36, 40) which has outlet openings (24, 36, 45) positioned at their circumference, the rotor being rotated by reaction on the rotor upon fluid flow from the outlet openings. The rotor operates within a fluid flow chamber (15) from which is conducted outwardly through a duct positioned thereabove. Inflow of fluid may be guided for linear flow by guide ribs (13). The rotor may be a hollow disk-like structure (FIGS. 1-3) with spiral guide vanes therebetween, or a T-shaped tubular structure (FIGS. 4-6).

Abstract: A diaphragm having a plurality of apertures each associated with a title block on the front panel of an indicator unit is provided to cause the various title blocks to be illuminated evenly from a light source positioned behind the diaphragm. The size, number and shape of the apertures is so chosen that all of the title blocks are equally illuminated regardless of their size and regardless of their distance to the light source. Indirect light is used to prevent the formation of shadows and light spots on the title blocks.

Abstract: Two surface electrodes are applied to an insulating substrate. The surface electrodes are totally surrounded by a metallic shield which is electrically floating, one of the electrodes being an emitter electrode emitting ac radiation and the other a receiving electrode. A portion of the emitted field is conducted by the shield. Upon approach, or touching of the shield by a grounded body, for example by the hand of a user, the field distribution within the shield will change and the radiation received by the receiving electrode will likewise change. In accordance with the present invention, an integrated circuit (IC) evaluation circuit is located beneath the metallic shield on the insulating substrate, the surface electrodes as well as external terminals passing through the insulated substrate being connected to the IC. Preferably, the shield is a plastic cap which is metallized, formed with snap tongs to snap over the insulated substrate.

Abstract: A leakage field capacitor has two adjacently located surface electrodes placed on an essentially plane support surface. A signal source is connected to one of the electrodes, so that this electrode, which may then be termed the transmitting electrode, will provide an electrical field which is sensed by the other, receiving electrode, which is connected to an evaluation circuit which evaluates disturbance of the field generated by the transmitting electrode. A metallic shield which is electrically floating i.e.