Surge testing and Error Area Ratio (EAR) basics
Most service centers perform some form of surge comparison testing, though terminology and methodology may vary. In simple terms, two winding responses or waveforms from a fast rise-time surge are compared and if there is an excessive difference, the unit under test may have a defect. The waveform that is produced by the pulse is unique to the unit under test, which for example, could be a stator winding. The waveform will be a function of the resistance, capacitance and inductance of the test circuit and quite a few variables can affect those characteristics.
- What is EAR?
- Pulse-to-Pulse (P-P EAR)
- Line-to-Line (L-L EAR)