(EN)
An ultrasonic detector (10) suitable for mounting in a position for surveying
an area for a source of airborne
ultra-sound, which detector comprises a sensor (20) for detecting an
ultrasonic sound signal, characterised by a transducer (64)
config-ured to produce a broadband ultrasonic sound signal for reception by
said sensor (20) enabling said ultrasonic detector to perform
a self-test.