Form d Developer (Nonaqueous Wet)
Form d is a nonaqueous wet developer in which fine powder is suspended in a quick-evaporating solvent and applied by aerosol spray, producing the highest sensitivity of any developer form.
Definition
Nonaqueous developers are the field standard for both visible and fluorescent PT, providing a uniform white contrast background that lifts penetrant from very tight defects.
Related terms
- Developer — A developer is a powdered or suspended absorbent material applied after penetrant removal that draws trapped penetrant out of surface defects by reverse capillary action, producing visible indications.
- Form c Developer (Water-Suspendable) — Form c developer is a water-suspendable powder that must be agitated continuously and applied by spray or immersion, forming a chalky coating that absorbs penetrant from defects.
- Solvent-Removable Penetrant — Solvent-removable penetrant is a Type I or II PT system in which excess penetrant is removed by wiping with a solvent-dampened cloth, used in field inspection where water rinsing is impractical.
More procedure terms
Contact Coupling · Immersion Testing · Source-to-Film Distance · Exposure Chart · Wet Particle Method · Dry Particle Method · Fluorescent Particles · Visible Particles · Demagnetization · Multi-Directional Magnetization
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.