MEASUREMENT OF PHYSICAL OR TECHNICAL VALUES OF VISCOUS MEDIA BY MEANS OF RAYLEIGH WAVES

摘要

The invention relates to a method for measuring physical or technical values of liquids by means of an acoustic transmission system for Rayleigh waves according to a wave guide principle. The inventive device comprises at least one measured section (100-106) formed by a solid surface made of nonpiezo-electric material. Said measured section can be brought into contact with the medium to be measured or with a transmission system, wherein at least one part of the acoustic wave emanating from the transmitter (1, 1') passes through at least one mode converter (3, 4, 34, 34', 34'', 34''', 34'''') on its way to the receiver (2, 2') and this part of the wave energy mode is converted at least partially by a Rayleigh wave (RW) into a volumetric sound wave (VW) or vice-versa. The device has a measured section made from a nonpiezo-electric material and the elements for exciting Rayleigh waves and/or for sensing Rayleigh waves and the measured section form separate components. When the principle of mode conversion is applied, at least one mode converter (3, 4, 34, 34', 34'', 34''', 34'''') is arranged, interacting with the measured section (5') or with an area connected to said measured section (5'). Said converter converts a volumetric sound wave (VW) running from the transmitter (1, 12) to the measured section (5') into a Rayleigh wave (RW) and/or converts a Rayleigh wave (RW) returning from said measured section (5') to the receiver into a volumetric sound wave (VW).