A two-in-one partial discharge sensor combines transient earth voltage and ultrasonic detection in a single unit for switchgear and ring main units. This article explains why the combination covers more defects and how the HMJ1010-AT is installed.
Two-in-One TEV and Ultrasonic PD Sensor for Switchgear and RMU Monitoring Read More »
Oscillating wave testing (OWTS, or damped AC – DAC) stresses a cable with a damped alternating wave and measures partial discharge while the cable stays in serviceable condition. This article explains the method and the HMJ9031 cable oscillating wave tester.
Non-dispersive infrared (NDIR) SF6 detectors measure gas concentration with dual-beam dual-wavelength optics and no consumable sensors. This article explains the technology and the HMJ-9051-S infrared quantitative leak detector for GIS substations.
NDIR SF6 Leak Detection: Dual-Beam Infrared Measurement for Substation Surveys Read More »
Inter-turn short circuits in generator rotors are common and dangerous if missed. Recurrent Surge Oscilloscope (RSO) testing detects them during overhauls without disassembling the rotor. This article explains the method and the HMJ7001 RSO detector.
SF6 leaks are expensive and environmentally significant, and they must be found and quantified. The negative ion capture principle gives a sensitive, stable and fast way to locate leaks on circuit breakers and GIS. This article explains how the HMJ-9051-SJ detector works.
A multi-channel partial discharge diagnosis system acquires many sensors at the same time and locates defects by comparing arrival times across channels. This article explains how the HMJ9041 works and when a multi-channel system is the right investment.
A portable integrated cable tester verifies cable length, cross-sectional area and material type on site, without laboratory equipment. This article explains how the HMJ9030 works and how field teams use it for acceptance and troubleshooting.
Metal-oxide surge arresters age slowly and fail suddenly. Monitoring the leakage current and its resistive component reveals varistor degradation early, and a lightning strike counter records every event. This article explains how the HMJ1011-WB leakage current sensor works.
Acoustic imaging locates partial discharge and pressurised gas leaks by overlaying the sound source on a live image. This article explains how the technology works and how a handheld detector with a digital microphone array shortens inspection time in substations and on overhead lines.
Oil-filled and cross-linked polyethylene cables degrade before they fail, releasing hydrogen, acetylene, methane and carbon monoxide into cable tunnels and ducts. This article explains why cable gas monitoring works, which gases matter, and how the HMJ1012-WLQ sensor detects them with ±1 ppm accuracy.