Wet Particle Method
The wet particle method uses fine ferromagnetic particles suspended in a low-viscosity oil or water carrier, sprayed or flooded over the magnetized surface to achieve higher sensitivity than the dry method.
Definition
Wet particles (typically 1–25 μm) flow easily into tiny defects and produce sharp indications. The carrier may be oil-based or water-based with surfactants and corrosion inhibitors. Wet method is the standard for production inspection.
Related terms
- Dry Particle Method — The dry particle method applies dry ferromagnetic powder to a magnetized surface using a hand bulb or shaker, used primarily for field inspection of rough welds and castings where wet method is impractical.
- Fluorescent Particles — Fluorescent particles are magnetic particles coated with a fluorescent pigment that emits visible light under UV-A (black light) illumination, providing higher sensitivity than visible particles by yielding bright indications against a dark background.
- Visible Particles — Visible particles are dark-colored ferromagnetic particles (typically black or red) used against a contrasting white background, inspected under white light without UV illumination.
- Magnetic Particle Testing (MT) — Magnetic Particle Testing (MT) is a surface and near-surface NDT method for ferromagnetic materials that detects discontinuities by applying a magnetic field and observing the leakage flux attract magnetic particles to the flaw indication.
More procedure terms
Contact Coupling · Immersion Testing · Source-to-Film Distance · Exposure Chart · Demagnetization · Multi-Directional Magnetization · Solvent-Removable Penetrant · Water-Washable Penetrant · Post-Emulsifiable Penetrant · Dwell Time
Where this comes up in practice
Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.
Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.