Corona Discharge Checker

MK-720 Corona Discharge Checker

MK-720 enables finding of insulation deterioration on insulators, disconnectors, and circuit breakers, at hot-line condition!

• Non-contact checking at hot-line condition is enabled by ultrasonic discharge sound detection.
• MK-720 distinguishes discharge from other noises by frequency analysis.
• Precise detection in ±8° area.
• MK-720 records measurement data. And the data is easily transferable to PC via USB cable.
• MK-720 generates audible sound from Corona discharge and transmits through an earphone.

Principle

Corona discharge induced by insulation deterioration of AC power facility generates ultrasonic wave on wide band.
Twice-frequency is clearly observed by frequency analysis of enveloped ultrasound because this ultrasonic wave changes its intensity synchronizing with phase of electric power.
MK-720 can detect discharge without influence of sounds occurred from other source by detecting strength of twice-frequency.

Specification