What Are the Types of Salt Spray Test Chambers?

Salt spray test chambers come in various types, primarily including Neutral Salt Spray (NSS) Test Chambers, Acetic Acid Salt Spray (ASS) Test Chambers, Copper-Accelerated Acetic Acid Salt Spray (CASS) Test Chambers, and Cyclic Salt Spray Test Chambers. Below is a detailed introduction to each type:

1. Neutral Salt Spray (NSS) Test Chamber

The neutral salt spray test is an accelerated corrosion test used to evaluate the corrosion resistance of protective and decorative coatings.

Features:

• Uses a 5% sodium chloride (NaCl) solution with a pH of 6.5–7.2.

• Operates at 35°C with ≥95% relative humidity.

• Continuous spray cycle (typically 24 hours per test).

Applications:

• Metals & alloys

• Metal coatings (electroplating, conversion coatings)

• Anodized films

• Organic coatings on metal substrates

2. Acetic Acid Salt Spray (ASS) Test Chamber

An evolution of the NSS test, ASS introduces glacial acetic acid to create an acidic environment.

Features:

• Collected solution pH: 3.1–3.3

• 3x faster corrosion rate than NSS

Applications:

• Decorative coatings (Cu/Ni/Cr or Ni/Cr)

• Anodized aluminum

3. Copper-Accelerated Acetic Acid Salt Spray (CASS) Test Chamber

A rapid corrosion test developed internationally, CASS adds copper chloride (CuCl₂) to intensify corrosion.

Features:

• 8x faster corrosion rate vs. NSS

• Test temperature: 50°C

Applications:

• Decorative coatings (Cu/Ni/Cr or Ni/Cr)

• Anodized aluminum

4. Cyclic Salt Spray Test Chamber

A combined corrosion test integrating salt spray + constant humidity/heat cycling.

Features:

• Simulates internal/external corrosion in enclosed products

• Alternates between salt spray & humid environments

• Evaluates electrical/mechanical performance degradation

Applications:

• Sealed electronic devices

• Automotive components

• Aerospace assemblies

Selection Guide

Pro Tip: For automotive parts, CASS + Cyclic tests are often combined to meet GMW 14872 standards.

Need help selecting the right chamber for your materials? Contact our testing experts today!