What type of instrument performs SFRA testing, and what features should an engineer look for?
An SFRA test set is a specialized two-port network analyzer. The RBX-H tester measures the windings' characteristic parameters inside the transformer, utilizing a sound internal fault frequency response analysis (FRA) method developed in world-leading countries, enabling accurate judgment of internal transformer faults. The SFRA tester has the laptop and chip microprocessor precision measurement systems, compact, easy to operate, with a comprehensive test analysis function.
|
Parameter |
Recommended Range |
Why It Matters |
|
Frequency range |
10 Hz – 2 MHz (min) |
Covers core, winding, and lead regions |
|
Dynamic range |
> 100 dB |
Ensures sensitivity across all bands |
|
Output impedance |
50 Ω (coaxial) |
Standard for repeatable connections |
|
Sweep points |
≥ 1000 (log spacing) |
Adequate resolution for peak detection |
|
Measurement accuracy |
± 0.5 dB mag, ± 1° phase |
Reliable inter-phase comparison |
|
Port configuration |
2-port (transmission + reflection) |
Full characterization capability |
Practical accessories checklist:
• Coaxial test leads (10 m, 15 m, 20 m sets)
• Alligator-to-BNC adapters for bushing terminals
• Earth ground connection kit
• Temperature/humidity logging (for record traceability)
• Software for correlation coefficient analysis and report generation
Pro tip: Always verify that the input impedance of the instrument matches the impedance of the coaxial cables. A 50 Ω mismatch introduces standing-wave artifacts above 500 kHz, leading to false "deformation" indications.