NOISE SILENCER AND METHOD FOR USE WITH AN ULTRASONIC METER

A silencer for use with ultrasonic meters to reduce stray ultrasonic noise that could cause measurement inaccuracies. The silencer comprises a tubular body having at least two baffles spaced apart from one another. The baffles are preferably formed of an open- cell, reticulated metal foam material that absorbs noise in the ultrasonic range of frequencies under high-pressure operating conditions. The silencer is a reasonable flow conditioner and can be mounted directly to the meter without disturbing the flow. The silencer reduces the level of ultrasonic stray noise by absorption. Ultrasonic noise waves are partially reflected between the baffles and along their length as the waves move between baffles. With each reflection, the baffle material absorbs energy that is lost by friction in the pores of the foam material. Through this process of the ultrasonic waves being reflected and the noise being incrementally absorbed, the energy of the ultrasonic wave is attenuated. El medio optico de grabacion (20) tiene un sustrato (1) y un hacinamiento de capas provistas encima del mismo. Una capa de grabacion de fase de cambio (5), teniendo un punto de fusion Tmp es emparedada entre una primera (3) y una segunda (7) capas dielectricas. Una capa aceleradora de cristalizacion (4, 6) esta siendo interpuesta en contacto con la capa de grabacion (5). Ademas una capa reflexiva (8) esta presente y una capa opcional de cubierta (9), La capa aceleradora de cristalizacion (4.6) consiste de una aleacion binaria de metal o un semiconductor y tiene un punto de fusion Tmg por lo menos 250°C mayor que el punto de fusion Tmp de la capa de grabacion (5) y tiene una estructura de cristal similar al estado cristalino de la capa de grabacion (5).