Overview
ISO 2361:1982 specifies a non-destructive magnetic method for measuring the thickness of electrodeposited nickel coatings on both magnetic (type A) and non‑magnetic (type B) substrates. It defines the measurement principle (magnetic attraction or magnetic reluctance), effective instrument ranges, calibration practice, factors affecting accuracy, and procedural precautions. The standard excludes-or flags as potentially inapplicable-autocatalytic (electroless) nickel coatings depending on their chemistry.
Key topics and requirements
- Measurement principle: Instruments either detect magnetic attraction between a permanent magnet and the coated surface or measure reluctance of a magnetic flux path through coating and substrate.
- Coating types: Distinguishes type A (nickel on magnetic substrates) and type B (nickel on non‑magnetic substrates).
- Typical measuring ranges:
- Magnetic‑attraction instruments: up to ~50 µm for type A, up to ~25 µm for type B.
- Reluctance instruments: much greater ranges-measurements up to ~1 mm or more.
- Calibration:
- Calibrate prior to use and check after warm‑up and at least once per day.
- Use coated calibration standards with similar substrate magnetic properties and surface roughness; thickness of calibration standard must be determined by coulometric or microscopical methods where appropriate.
- For thin substrates, match basis‑metal thickness of standard and specimen or use a back‑up method.
- Factors affecting accuracy:
- Substrate magnetic properties, residual magnetism, strong external magnetic fields.
- Surface roughness, foreign particles, probe cleanliness and pressure, probe orientation, curvature and edge effects (influence can extend up to ~20 mm from discontinuities).
- Magnetic properties of the nickel deposit (composition, brightness vs. dull, heat treatment effects).
- Procedure & sampling:
- Clean surfaces without removing coating; avoid defects and edges; place probe generally perpendicular to surface.
- Take multiple readings per measurement point (local variability and instrument repeatability-at least five readings where indicated).
- Accuracy requirement: The method should determine coating thickness to within 10% of true thickness or 1.5 µm, whichever is greater.
Applications and users
ISO 2361 is used for routine, non‑destructive thickness control in:
- Electroplating and surface‑finishing shops
- Quality control labs in automotive, aerospace, electronics and hardware manufacturing
- NDT technicians, metallurgists, and coating inspectors
- Suppliers and purchasers requiring contractual verification of electrodeposited nickel thickness
Keywords: ISO 2361, electrodeposited nickel, coating thickness measurement, magnetic method, non‑destructive testing, calibration standards, magnetic substrates, non‑magnetic substrates.
Related standards
- ISO 1463 - Microscopical method for coating thickness (reference for calibration)
- ISO 2177 - Coulometric (anodic dissolution) method for thickness determination
- ISO 2064 - Definitions and conventions for metallic and other non‑organic coatings
This summary focuses on practical application, calibration and accuracy considerations for reliable magnetic measurement of electrodeposited nickel coatings as defined in ISO 2361:1982.
Open preview (PDF)Electrodeposited nickel coatings on magnetic and non-magnetic substrates — Measurement of coating thickness — Magnetic method