Eddy Current Testing (ET) Level I & II Certification Course

Unlike Visual Testing (observe the surface), Penetrant Testing (apply, remove, observe), or even Magnetic Particle Testing (apply field, observe indications), Eddy Current Testing requires the technician to interpret abstract impedance plane signals — not visible indications on the test material. The shape, phase angle, amplitude, and trajectory of a signal on an impedance plane display must be correctly interpreted to distinguish a crack from liftoff, a pit from a support plate, or alloy variation from wall thinning. This requires deep theoretical understanding and significant hands-on practice. Trinity NDT’s ET course spends more time on impedance plane interpretation than any other subject — because this is where ET competence is actually built or lost.

Conventional Eddy Current Testing works well on non-ferromagnetic materials (copper alloys, stainless steel, titanium, aluminium) but cannot inspect through the full wall of ferromagnetic materials like carbon steel or low-alloy steel tubes because the high magnetic permeability confines the eddy currents to a very thin surface layer. Remote Field ET (RFET) uses a different physical principle — an exciter coil and receiver coil spaced approximately two tube diameters apart — that allows full-wall penetration of ferromagnetic tubes. RFET is used for carbon steel boiler tubes and cast iron water mains that conventional ET cannot inspect effectively.

The Level II certification course (40–80 hours classroom + practical) teaches you the principles and gives initial hands-on tube inspection experience. However, proficiency in tube inspection data interpretation typically develops over 3–6 months of on-the-job experience with actual heat exchanger data — dealing with real-world signals from corroded, pitted, and worn tubes in production environments. Trinity NDT’s course is specifically designed to give you the theoretical depth and practical foundation that makes this learning curve as short as possible. We use actual refinery-grade tube specimens with real defect profiles — not artificial classroom specimens.

The ASNT SNT-TC-1A ET Level II theory component is fully available in our live virtual online format via Zoom. The written general and specific examinations are also conducted online under supervision. The resulting certification is the same as for offline participants. However, the practical component — actual operation of an EC instrument, tube probe insertion, and signal interpretation on a live display — is only possible in the offline Bangalore course. For online graduates who need to demonstrate practical competence to their employer, a separate practical add-on session at our Bangalore laboratory can be arranged.

As per ASNT SNT-TC-1A (2024 edition) Table 6.3, the minimum on-the-job training hours for ET Level II (direct entry) are 630 hours. If the candidate completes Level I first (200 OJT hours), and then upgrades to Level II, an additional 430 hours of OJT is required. OJT hours are accumulated at the workplace under supervision and must be documented and signed by the employer’s Level III before the final certification examination. Attending Trinity NDT’s training course counts toward the classroom training requirement — the OJT hours are accumulated separately at your workplace.

The highest demand for ET Level II in India is in petroleum refinery heat exchanger inspection — every IOCL, HPCL, BPCL, Reliance, and ONGC refinery conducts annual or biennial turnaround inspections requiring ET teams. Power generation companies (NTPC, BHEL, Tata Power) need ET for boiler and condenser tube inspection. Aerospace companies (HAL, ISRO, DRDO) require NAS 410 ET Level II for surface crack detection. Salaries: ₹3.5–5 LPA for freshers in India, rising to ₹8–15 LPA with 5 years of heat exchanger and aerospace experience. Gulf market: USD 3,000–6,000/month for experienced ET tube inspectors on refinery turnaround contracts.