This instrument detects the low level ultrasonic frequencies emitted by small sparks to enable the user to closely pinpoint insulator faults. It is a robust one piece unit, operated by a single push switch with an audible output through loudspeaker or optional headphones.
Features
Detects low level ultrasonic frequencies emitted by small sparks
Elliptical shaped dish allows for close pin-pointing of fault location
Audio signal through loudspeaker or headphones
Robust one piece unit
Operation by a push switch and pointed at the target. A sight system through the base is used for visually locating which insulator is faulty. A loudspeaker will produce a sound.
A meter is available for signal strength levels, and also to check the battery voltage
Background
Minor electrical insulator faults caused by small sparks can be a significant cause of radio interference. These small sparks causing radio and television interference are so small that they cannot be heard, even when the listener is close to the source.
While a sensitive microphone and high gain amplifier can detect very low level sounds, they also amplify other ambient audio frequencies such as motor vehicles, bird sounds and people talking.
Fortunately, a spark, because of its sharp rise time, also emits much of its noise above the human hearing range where very little natural noise exists. STIL Ultrasonic Detectors use this feature and have an amplifying reflector providing both a very high gain, and sufficient directionality to pick out one faulty insulator in a string of insulators
