Detailed analysis of eddy current testing (ECT) systems used in rail surface and near-surface defect detection.
Core Components
| Component |
Function |
Range |
Resolution |
| Probe Array |
Detection |
0-10mm |
0.1mm |
| Excitation Unit |
Field Generation |
0-2MHz |
1kHz |
| Signal Processor |
Analysis |
24-bit |
Real-time |
| Position Encoder |
Location |
0.1mm |
Continuous |
| Data Logger |
Recording |
100MB/s |
Synchronized |
Probe Specifications
| Parameter |
Surface |
Sub-surface |
Special |
| Frequency |
100-500kHz |
10-100kHz |
500kHz-2MHz |
| Coil Size |
2-5mm |
5-10mm |
1-2mm |
| Channel Count |
8-32 |
4-16 |
16-64 |
| Lift-off |
0.5-2mm |
1-3mm |
0.1-0.5mm |
| Coverage |
50-150mm |
25-75mm |
10-30mm |
Detection Capabilities
| Defect Type |
Depth |
Min Size |
Reliability |
| Surface Cracks |
0-2mm |
0.3mm |
95% |
| RCF Damage |
0-5mm |
0.5mm |
90% |
| Head Checks |
0-3mm |
0.4mm |
92% |
| Gauge Corner |
0-4mm |
0.5mm |
93% |
| Squats |
0-7mm |
1.0mm |
88% |
Operating Parameters
| Parameter |
Standard |
High-Speed |
Special |
| Speed |
40 km/h |
80 km/h |
20 km/h |
| Sampling Rate |
50kHz |
100kHz |
200kHz |
| Resolution |
0.5mm |
1.0mm |
0.2mm |
| Lift-off |
1.0mm |
1.5mm |
0.5mm |
| Coverage |
100% |
90% |
100% |
Signal Processing
| Stage |
Method |
Output |
Time |
| Filtering |
Digital |
Clean Signal |
Real-time |
| Analysis |
Phase/Amplitude |
Defect Data |
Real-time |
| Classification |
AI/ML |
Defect Type |
<1s |
| Mapping |
Position-based |
Location |
Real-time |
| Recording |
Compressed |
Archive |
Continuous |
Calibration Requirements
| Type |
Frequency |
Method |
Standard |
| Basic |
Daily |
Reference Block |
±5% |
| Full |
Weekly |
Calibration Set |
±2% |
| Phase |
Monthly |
Standard Block |
±1° |
| System |
Quarterly |
Laboratory |
ISO 17025 |
| Annual |
Yearly |
Certification |
National |
Environmental Factors
| Factor |
Impact |
Mitigation |
Limits |
| Temperature |
High |
Compensation |
-10 to +50°C |
| Moisture |
Medium |
Sealing |
IP67 |
| EMI |
High |
Shielding |
<40dB |
| Vibration |
Medium |
Isolation |
<2g |
| Speed |
High |
Adaptive |
<80 km/h |
Data Collection
| Type |
Rate |
Storage |
Format |
| Raw |
100MB/s |
Binary |
Custom |
| Processed |
50MB/s |
Analysis |
HDF5 |
| Position |
1MB/s |
Location |
CSV |
| Defects |
10MB/s |
Database |
SQL |
| Reports |
1MB/s |
Summary |
PDF |
Maintenance Schedule
| Task |
Daily |
Weekly |
Monthly |
| Probe Check |
✓ |
– |
– |
| Calibration |
✓ |
– |
– |
| System Test |
– |
✓ |
– |
| Data Verify |
✓ |
– |
– |
| Full Service |
– |
– |
✓ |
Quality Control
| Check |
Method |
Frequency |
Tolerance |
| Sensitivity |
Standard |
Daily |
±5% |
| Phase Angle |
Vector |
Weekly |
±2° |
| Lift-off |
Gap Block |
Daily |
±0.1mm |
| Position |
Encoder |
Weekly |
±0.5mm |
| System |
Full Test |
Monthly |
±2% |
Analysis Features
| Feature |
Method |
Accuracy |
Update |
| Pattern Recognition |
AI |
95% |
Monthly |
| Depth Sizing |
Neural Net |
±0.5mm |
Quarterly |
| Classification |
Machine Learning |
92% |
Monthly |
| Trending |
Statistical |
90% |
Weekly |
| Prediction |
AI Model |
85% |
Monthly |
Reporting System
| Report Type |
Content |
Timing |
Format |
| Real-time |
Alerts |
Immediate |
Screen |
| Shift |
Summary |
Daily |
PDF |
| Analysis |
Details |
Weekly |
Excel |
| Trending |
Patterns |
Monthly |
Charts |
| Certification |
Results |
Annual |
Official |
