Detection of ultrasonic waves

Ultrasonic waves can be detected by various methods as listed below:

(a)Using radiometer: Ultrasonic waves can be detected using Radiometer. In this method ultrasonic beam is made to fall on a thin mica fan suspended by a thin wire carrying a small mirror from one end of a light rod. Due to pressure exerted by ultrasonic waves the fan gets detected along with the mirror. The deflection can be noted by a lamp and scale arrangement. A beam of light is made incident on the mirror and reflected beam falls back on the origin of scale attached to lamp. When mirror shows deflection by angle 0, then reflected beam on the scale defects by angle 20. Since 20 can be noted from scale, hence deflection of mirror can be found. The deflection is directly proportional to the intensity of ultrasonic waves. Hence we can calculate the intensity of ultrasonic waves with this method. Continue reading “Detection of ultrasonic waves”