Abstract: Described is a suction device for cleaning the skin, the device having a suction nozzle with several openings, plus a gap. The skin is drawn by a pulsating suction force into the openings where it closes off the gap in which a pulsating compression force synchronized with the suction force is generated. Comedones are thus squeezed out of the pores by short, variable compressive thrusts.

Abstract: A suction device for cleaning skin having a suction nozzle with a plurality of openings that are covered by an elastic diaphragm which is drawn into the openings by a pulsating drive force so that the diaphragm forms a plurality of pulsating secondary vacuum pumps in contact with the skin, thus, the vacuum action on the skin is divided into short variable suction pulses and the covering elastic diaphragm offers an easily exchangeable disposable hygienic protection.

Abstract: A laser beam is directed onto a light detector along a path passing close to the spray orifice(s) of a fuel-injector spray nozzle. The photoelectric signal produced by the light detector is fed to an automatic signal-content evaluating unit. To test the nozzle for proper buzzing, fuel is applied to the nozzle at a predetermined pressure and volumetric flow rate preferably corresponding to those for which the nozzle is designed. If the nozzle buzzes properly the photoelectric signal is pulsating, otherwise continuous. To test the nozzle for seal-tightness, fuel is applied to the nozzle for a limited testing interval at a pressure lower by a predetermined amount than the opening pressure of the spray nozzle. If the nozzle is insufficiently seal-tight, drops of fuel are discharged from the spray orifice(s) resulting in corresponding alteration of the photoelectric signal.