The MA40S4S and MA40S4R from Murata provide an ultrasonic transducer system which may be used for remote detection of objects and for distance measurement using the time-of-flight principle. The MA40S4S is an ultrasonic transmitter offering a maximum sound pressure level of 120dB. The MA40S4R is an ultrasonic receiver which provides sensitivity of -63dB.
This pair of devices is optimized to provide long range and accurate detection of objects when operating at a sound frequency of 40kHz. The MA40S4S and MA40S4R consist of piezoelectric ceramic sounders, a metal plate, a resonator, and a resin case. The resonator has a funnel shape to transmit ultrasonic waves efficiently in the transmitter, and to concentrate waves at the center of the resonator in the receiver.
Because the MA40S4S and MA40S4R have an open structure, they are only suitable for use indoors.