Ultrasonic detector
Updated 2026-10-27
Data records
- Airborne sensors, among them flexible-tube, close-range and parabolic long-range types with a viewfinder and laser pointer, receive ultrasound through the air, as distinct from contact sensors that pick up structure-borne ultrasound from a machine casing.
- Because the detection is acoustic, enclosed switchgear and cabinets can be scanned at any voltage level before they are opened, and a scan of the closed gear precedes further inspection.
- An ultrasonic detector senses the high-frequency sound that corona, tracking and arcing emit at an electrical fault, sound above the range of hearing, and the same instrument detects mechanical vibration.
- Discharges emit ultrasound in their earliest stages, long before they generate heat, so an ultrasonic detector finds a fault at a stage infrared thermography cannot see; the two methods are combined, each having its own strengths.
- The instrument translates the ultrasound into the audible range by heterodyning, so that the inspector hears the discharge through headphones, and the sound can be recorded and analyzed to help judge its severity.
- A data-collecting detector shows a decibel level and a temperature reading, stores sound recordings and photographs of the test point from an on-board camera, and carries an on-board spectrum analyzer, with stored history for trending.
- The same detectors locate compressed air and other leaks and faulty steam traps from the ultrasound they emit, which is a separate application from electrical inspection.
- The instrument pinpoints the location of an electrical discharge, and spectral analysis software identifies sound patterns that relate to the severity of the discharge.
- A permanently mounted airborne sensor monitors the condition of an electrical cabinet continuously through a standard measurement system.
Elsewhere in the family
- Partial Discharge Online related entry on Electrical Testing Reference
- Partial Discharge Online related entry on Switchgear Testing Reference
- Partial Discharge Online related entry on Transformer Testing Reference
Sources
- SDT application page, Electrical Fault Detection with Ultrasound, web page edition, SDT Ultrasound Solutions. Held as: Public page. Publisher page
- SDT product page, Airborne Ultrasound Sensors, web page edition, SDT Ultrasound Solutions. Held as: Public page. Publisher page
- UE Systems application page, Electrical Inspection with Ultrasound, web page edition, UE Systems. Held as: Public page. Publisher page
- UE Systems product page, Ultraprobe 15,000, web page edition, UE Systems. Held as: Public page. Publisher page
Changelog (24 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (instr.ultrasonic-detector.airborne-vs-structure-borne) | |
| 2026-10-27 | revised (instr.ultrasonic-detector.airborne-vs-structure-borne) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.airborne-vs-structure-borne) | |
| 2026-10-27 | created (instr.ultrasonic-detector.closed-cabinet) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.closed-cabinet) | |
| 2026-10-27 | created (instr.ultrasonic-detector.definition) | |
| 2026-10-27 | revised (instr.ultrasonic-detector.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.definition) | |
| 2026-10-27 | created (instr.ultrasonic-detector.early-detection) | |
| 2026-10-27 | revised (instr.ultrasonic-detector.early-detection) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.early-detection) | |
| 2026-10-27 | created (instr.ultrasonic-detector.heterodyning) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.heterodyning) | |
| 2026-10-27 | created (instr.ultrasonic-detector.instrument-features) | |
| 2026-10-27 | revised (instr.ultrasonic-detector.instrument-features) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.instrument-features) | |
| 2026-10-27 | created (instr.ultrasonic-detector.leak-detection) | |
| 2026-10-27 | revised (instr.ultrasonic-detector.leak-detection) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.leak-detection) | |
| 2026-10-27 | created (instr.ultrasonic-detector.localization-spectral) | |
| 2026-10-27 | revised (instr.ultrasonic-detector.localization-spectral) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.localization-spectral) | |
| 2026-10-27 | created (instr.ultrasonic-detector.permanent-sensor) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (instr.ultrasonic-detector.permanent-sensor) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Ultrasonic detector." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/instruments/ultrasonic-detector/.
Test Instrument Reference, Ultrasonic detector (Oct. 27, 2026), https://www.testinstrumentreference.com/instruments/ultrasonic-detector/.
@misc{etr-instruments-ultrasonic-detector,
title = {Ultrasonic detector},
howpublished = {\url{https://www.testinstrumentreference.com/instruments/ultrasonic-detector/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=Ultrasonic detector |website=Test Instrument Reference |publisher=Test Instrument Reference |url=https://www.testinstrumentreference.com/instruments/ultrasonic-detector/ |date=2026-10-27 |access-date=}}