PROCEDIMIENTO Y DISPOSITIVO PARA DETERMINAR LA SECCION TRANSVERSAL POR UNIDAD LONGITUDINAL DE PRODUCTOS DE LA IN- DUSTRIA TEXTIL.

摘要

1356957 Acoustic measurement of physical properties ZELLWEGER Ltd 8 June 1971 [16 June 1970] 19390/71 Addition to 1347695 Heading H4D [Also in Division D1] The sensitivity of the parent system to changes in the sound wave transit time is enhanced by using a resonator in the sound field. In the Fig. 4 embodiment the sound generator 10 and pick-up 12 are each associated with a resonance chamber 20, 22, so that a stationary wave sound field is set up. The textile product 15, whose weight per unit length is to be tested, is guided through a nodal or anti-nodal region of the field. To compensate for changes in transit time caused by influences other than the product 15 variations a reference sound path is provided as in the parent system and the reference pick-up output signal is compared with pick-up 12 output. The chambers are tuned to the working frequency or a harmonic thereof. One chamber may be omitted.