# SSPC-PA 9

Source: https://coatmentor.com/standards/sspc-pa-9/ · Updated 2026-10-14

How many ultrasonic thickness readings to take on non-metal substrates, and how to judge them.

**Publisher**: AMPP (SSPC)

**Area**: Application and film thickness

SSPC-PA 9 does for coatings on concrete and other non-metal substrates what SSPC-PA 2 does on steel: it says how many readings to take with an ultrasonic gauge and how to judge them. The gauge itself is operated to ASTM D6132.

## The sampling

A spot is the average of at least three readings, as in PA 2, but taken within a larger circle, about 15 cm (6 in.) across. Five spots make an area of about 10 m², and the number of areas follows the size of the coated surface.

## The trap

The spot circle is the difference to remember: 4 cm (1.5 in.) in SSPC-PA 2 on metal, about 15 cm (6 in.) in SSPC-PA 9. Older editions covered only cementitious substrates.

**1** practice item in the members area mentions SSPC-PA 9 (CIP 2: 1).

## Related

- **Concepts:** [Dry film thickness measurement](https://coatmentor.com/learn/dft-measurement/) · [Reference (control) areas](https://coatmentor.com/learn/reference-areas/)
- **Standards:** [ASTM D6132](https://coatmentor.com/standards/astm-d6132/) · [SSPC-PA 2](https://coatmentor.com/standards/sspc-pa-2/)

## About this page

This page describes the subject of SSPC-PA 9 in our own words; it does not reproduce the standard. For the full text, buy the current edition from AMPP. Checked on 2026-10-14; errors go in the [corrections log](https://coatmentor.com/method/). CoatMentor is an independent study aid. It is not affiliated with ISO, AMPP, SSPC, NACE International, ASTM or FROSIO.