How to Choose a Partial Discharge Detector: A Practical Guide for Utility Engineers
Compare TEV, ultrasonic, HFCT, and UHF partial discharge detection methods. Find the right PD detector for switchgear, transformers, and cables from the Unitech Tools range.
Table of Contents
Choosing the right partial discharge detector depends on the type of equipment you inspect, the environment, and your budget. Each detection method has strengths for specific applications:
| Method | Detects | Best For | Equipment Cost |
|---|---|---|---|
| TEV (Transient Earth Voltage) | Surface PD pulses | Air-insulated switchgear, panels | Low–Medium |
| Ultrasonic (AE) | Acoustic PD energy | Transformers, GIS, cable terminations | Low–Medium |
| HFCT (High-Frequency CT) | Cable PD pulses | Power cables, cable terminations | Medium |
| UHF (Ultra-High Frequency) | Electromagnetic PD | GIS, transformers (internal PD) | High |
The SC Series PD Detector from Unitech Tools combines TEV, ultrasonic, and HFCT methods in a single handheld instrument — giving you three complementary detection methods without carrying separate devices.
Key features of the SC Series:
- TEV sensor (built-in): Measure PD magnitude in dBmV on switchgear panels — place the sensor on the panel surface, get instant reading
- Ultrasonic sensor (contact): Detect airborne and structure-borne PD in transformers, GIS, and cable boxes
- HFCT clamp: Connect around cable earth straps or ground conductors to measure PD in cable systems
- Phase-resolved pattern display: Classify PD type — distinguish corona, surface discharge, and internal voids
- Threshold alarm: Programmable thresholds for green/yellow/red PD severity levels
The SC Series is the most popular PD detector for utilities in Latin America and Africa because it covers the three most common PD detection methods in a single device at a competitive price point.
For simpler inspection workflows or budget-constrained applications, the HPD200 and HPD500 handheld PD detectors offer focused TEV + ultrasonic detection in an even more compact form.
| Model | Methods | Best For |
|---|---|---|
| HPD200 | TEV + Ultrasonic | Switchgear PD screening, basic TEV surveys |
| HPD500 | TEV + Ultrasonic + HFCT | Comprehensive switchgear + cable inspection |
| SC Series | TEV + US + HFCT + Pattern | Advanced PD analysis, classification, trending |
Use this decision process to select the right partial discharge detector for your needs:
- What equipment do you inspect? Switchgear only → HPD200 or SC Series. Switchgear + cables → HPD500 or SC Series. Transformers + GIS → SC Series with ultrasonic capability.
- Do you need PD classification? For distinguishing corona from surface discharge, choose the SC Series with PRPD pattern display.
- What's your budget? Entry-level → HPD200. Mid-range → HPD500. Professional → SC Series.
- Do you also need acoustic camera capability? Consider adding the GSW acoustic camera for rapid substation PD screening before detailed TEV analysis.
Browse the full PD detector range from Unitech Tools for specifications and OEM/ODM inquiries.
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