| 摘要 |
<p>PURPOSE:To prevent a transmitter receiver coupled with an ultrasonic guide tube from rising in temperature and to prevent the function of the transmitter receiver from decreasing owing to heat as much as possible by constituting the ultrasonic wave guide pipe which constitutes an ultrasonic sensor by using a material which has small heat conductivity. CONSTITUTION:Ultrasonic wave guide pipes 12 and 14 are made of materials which high heat resistance and extremely small heat conductivity. Consequently, the conduction of heat to a transmitter 10 and a receiver 11 is reduced and prevented from rising in temperature as much as possible. Further, the guide pipes 12 and 14 are made of the materials which have high heat resistance and small heat conductivity, so the convection of heat in the guide pipes 12 and 14 is reduced, the temperature gradient in the guide pipes decreases, and the attenuation rate of ultrasonic waves propagated in the guide pipes 12 and 14 decreases, so that the propagation efficiency of the ultrasonic waves in the guide pipes 12 and 14 is improved to the contrary.</p> |
