EDDY CURRENT TRAINING OF NDT TECHNICIANS
Reliability and accuracy apply
to the two basic measurement of the quality of ECT testing.
Reliability applies to detection and accuracy applies to sizing.
Reliability is defined as a product of probability of detection and
(1- false call rate). Reliability is highest when 1) all defects are
detected and 2) no false calls are made. Accuracy is a measure on
how well the defects are sized. Accuracy refers to the error in
sizing a defect. For a high quality ECT test both the reliability
and accuracy are important parameters.
NDE Associates, Inc.
has a very intense program for training ECT technicians. Technicians
are trained on a mockup bundle in the laboratory and historical data
taken during previous inspections. Mockup bundle includes tubes
removed from the heat exchangers with in-service defects and
deposits. Historical data includes ECT dta stored from previous
inspections. In addition, technicians are trained to resolve valid
defect signals from non-defect signals (false call signals). Our
library of ECT training data base includes:
- defects in free span. Defects to include pits, cracks, wall loss and vibration wear
- defects under supports. Defects to include OD vibration wear, OD cracking, OD and ID pits etc.
- defects in U-bends
- tubes with multiple defects. Technicians are trained to detect the deepest among hundreds of defects.
- tubes with defects and metallic
deposits. This tests the ability of the inspector to discriminate
between metallic deposits and real defects.
NDE Associates, Inc.
515 Tristar Drive
Webster, TX 77598
Phone: 281-488-8944 Fax: 281-488-8485
