ULTRASONIC RECEPTION APPARATUS FOR PROPAGATION TIME MEASUREMENT OF ULTRASONIC AND ULTRASONIC RECEPTION METHOD FOR PROPAGATION TIME MEASUREMENT OF ULTRASONIC

摘要

PROBLEM TO BE SOLVED: To provide an ultrasonic reception apparatus capable of precisely receiving ultrasonic signals by eliminating noise signals or reflected wave signals without increasing a threshold for determining detection time of an ultrasonic signal.;SOLUTION: An ultrasonic receiver receives an ultrasonic signal transmitted from a sensor unit disposed in a target space of temperature measurement. A processor determines whether the signal level of an envelope of the received signal within a range between a first predetermined value and a second predetermined value larger than the first predetermined value satisfies a predetermined condition for determining that the received signal is the ultrasonic signal transmitted from the sensor units. When the envelope of the received signal satisfies the predetermined condition, the processor determines that received signal is the ultrasonic signal.;COPYRIGHT: (C)2014,JPO&INPIT