SSPC PA-2

“Measurement of Dry Coating Thickness with magnetic Gages”

HOW MUCH IS ENOUGH?

Statistical method to determine the minimum number of readings required.

SSPC-PA 2 – Measurement of Dry Paint Thickness with Magnetic Gauges

• Procedures to Measure Dry Film Thickness of Nonmagnetic Coatings over Magnetic Substrates

–Type 1 – Magnetic Pull-Off

–Type 2 – Fixed Probe

• Calibration – Type 1

–Verify accuracy on NIST plates

–Measure  (A) several points on bare, prepared substrate

–Measure (B) the dry film

–Subtract (A) from (B) to obtain dry film thickness

• Calibration – Type 2

–Verify accuracy on nonmagnetic shims over the bare, prepared substrate

• For Structures not exceeding 300 sq ft, take 5 spot readings per 100 sq ft
• For Structures not exceeding 1000 sq ft, Select 3 random 100 sq ft areas to test
• For Structures exceeding 1000 sq ft, Select 3 random 100 sq ft areas to test in the first 1000 sq ft and for each additional 1000 sq ft test one random 100 sq ft area.
• If any area is not in compliance, the non compliant area should be determined.