DGS (Distance Gain Size) Curve | DGS UT Practical | Ultrasonic Testing Level II | Step-by-Step Demo

BS TECHNICAL EDUCATION MUMBAI For NDT LEVEL II TRAINING CONTACT 📱 8076743027 In this practical video, we explain the DGS (Distance Gain Size) technique used in Ultrasonic Testing (UT) for sensitivity setting and evaluation of reflector size. The DGS method relates Distance, Gain and Size and allows the ultrasonic operator to compare the response from an unknown reflector with theoretically derived responses from disk-shaped reflectors. 🔍 Topics Covered What is DGS / AVG method? Principle of Distance Gain Size DGS curve and its interpretation Near Field Length (NFL) Effective probe diameter Reference/back-wall echo Setting DGS reference sensitivity How to select the DGS curve Practical measurement of reflector response Equivalent Reflector Size (ERS) Reading reflector size from the DGS curve DGS vs DAC Practical demonstration using an ultrasonic flaw detector Important precautions and limitations 📐 Basic DGS Concept D = Distance → Sound path distance to the reflector G = Gain → Gain required to obtain a particular echo height S = Size → Equivalent size of a disk-shaped reflector The general DGS diagram normalizes distance using the probe's effective near-field length and reflector size using the effective transducer diameter. 🎯 Practical Objective After completing this demonstration, the learner should be able to: Probe → Calibration → Reference Echo → DGS Curve → Reflector Echo → ERS Evaluation DGS is particularly useful because the instrument can use mathematically derived curves to evaluate reflector responses rather than requiring a separate reference reflector at every distance, although the applicable procedure, probe characteristics, material and reference requirements must always be considered. 📚 Recommended for ✅ NDT Level II Students ✅ UT Level II Technicians ✅ NDT Inspectors ✅ Welding Inspectors ✅ QA/QC Engineers ✅ NDT Trainers ✅ Ultrasonic Testing Practical Training #DGS #DGSUT #DistanceGainSize #UltrasonicTesting #UTLevel2 #NDT #NDTTraining #DGSMethod #AVG #UltrasonicTestingPractical #UTPractical #NDTLevel2 #DAC #ERS