Ultrasonic Sensor Handheld Partial Discharge Tester

A: It detects the ultrasonic waves​ (high-frequency sound waves) produced by partial discharge (PD)​ activity. PD includes electrical arcing, tracking, and corona discharge that are inaudible to the human ear but are early warning signs of insulation breakdown.

A: The primary advantage is the ability to pinpoint the exact location​ of the discharge. Ultrasound is highly directional, allowing you to "follow the sound" to its source, even on complex equipment like switchgear. It is also excellent for scanning energized equipment from a safe distance.

A: Use the Directional Dish (Parabolic Sensor):​ For scanning equipment from a distance (inches to several feet) to locate the general area of PD. Ideal for overhead busbars, insulators, and external components.

Use the Contact Probe (Stethoscope Module):​ For zeroing in on the exact source by placing it directly on the equipment surface. It listens to vibrations transmitted through solid materials and is essential for identifying internal faults in transformers or behind metal panels.

A: Not necessarily. A steady 50/60 Hz hum is typically magnetostriction​ from transformer cores or coil vibration, which is normal. PD usually sounds like erratic crackling, sizzling, or popping. The key is to distinguish random, irregular noises from steady mechanical hums.

A: Yes, but it can be challenging. The headphones help isolate the sound. For best results:

Use the contact probe to minimize airborne noise.

Touch the probe to different points; the sound will be loudest at the source.

Some models have a frequency tuning feature to help filter out background noise.