ASTM D8331

Introducing ASTM D8331 – Industrial Physics

ASTM D8331 is the standard test method for measuring the film thickness of thin‑film organic coatings using non‑destructive ruggedized optical interference. This method provides a fast, precise, and repeatable way to verify coating thickness on coil‑coated materials during production or in the laboratory.

Accurate coating‑thickness measurement is essential for ensuring product performance, reducing waste, validating supplier specifications, and maintaining consistent quality across coated substrates.

What ASTM D8331 Covers

ASTM D8331 outlines procedures for non‑destructive optical measurement of thin‑film coatings. Key elements include:

• Measuring film thickness on coil‑coated organic layers
• Using ruggedized optical interference technology
• Performing measurements in‑process or in a laboratory setting
• Ensuring consistent calibration and measurement parameters
• Supporting both SI and inch‑pound units

The method applies to:

• Coil‑coated metals
• Organic thin‑film coatings
• Painted and coated industrial substrates
• R&D, QC, and production‑line verification

ASTM D8331 provides a standardized, reliable way to confirm coating thickness without damaging the sample.

Where ASTM D8331 Is Used

This standard is widely used across industries that rely on precise coating control, including:

• Coil coating and metal packaging
• Automotive and appliance manufacturing
• Architectural and industrial coatings
• Specialty coatings and engineered surfaces
• R&D and quality‑control laboratories

It supports both continuous production monitoring and detailed laboratory analysis.

Why Coating Thickness Measurement Matters

Accurate coating‑thickness data is essential for:

• Ensuring product durability and performance
• Reducing material waste and rework
• Validating supplier and customer specifications
• Improving process control and consistency
• Supporting regulatory and industry compliance

Non‑destructive optical measurement allows manufacturers to verify coating quality without interrupting production.

Testing solutions for ASTM D8331

Industrial Physics offers several SpecMetrix systems that align directly with ASTM D8331’s non‑destructive optical‑interference requirements:

SpecMetrix In‑Line Coating Measurement Systems

Designed for real‑time, in‑process coating‑thickness measurement, SpecMetrix in‑line systems use ruggedized optical interference to deliver continuous, high‑resolution data. They help manufacturers maintain tight coating tolerances, reduce waste, and optimize production efficiency — all while meeting ASTM D8331 requirements.

SpecMetrix Enhanced Lab System

A laboratory‑grade system for precise, non‑destructive coating‑thickness measurement. The Enhanced Lab System provides fast, repeatable results for R&D, QC, and material qualification. It’s ideal for validating production‑line performance and ensuring coatings meet ASTM D8331 specifications.

SpecMetrix Advanced Lab System

A high‑performance lab solution offering expanded measurement capabilities, advanced analytics, and superior resolution. The Advanced Lab System is designed for complex coatings, multi‑layer structures, and demanding R&D environments where ASTM D8331 compliance and ultra‑precise measurement are essential.

Together, these SpecMetrix systems give manufacturers a complete toolkit for verifying coating thickness across production lines, laboratories, and specialized applications.

Your Global Test and Measurement Partner for ASTM D8331

Industrial Physics supports manufacturers with the tools and expertise needed to measure coating thickness in line with ASTM D8331. From in‑line optical systems to advanced laboratory analyzers, we help ensure your coatings perform as designed — consistently, accurately, and efficiently.