A salt spray test chamber can perform three types of tests: Neutral Salt Spray (NSS), Acetic Acid Salt Spray (ASS), and Copper-Accelerated Acetic Acid Salt Spray (CASS). Since each test has different performance requirements, their respective standards also vary. Below, we explain the three test standards for this equipment:
1. Neutral Salt Spray (NSS) Test Standard
- Dissolve chemically pure sodium chloride in distilled water at a concentration of 50±5 g/L.
- Measure the pH of the solution using a pH meter or precision pH test paper (calibrated with a pH meter for routine checks).
- Adjust the pH of the solution (if necessary) using chemically pure hydrochloric acid or sodium hydroxide to maintain the collected salt spray pH between 6.2–7.2.
- Filter the solution before use to prevent nozzle clogging.
2. Acetic Acid Salt Spray (ASS) Test Standard
- Dissolve chemically pure sodium chloride in distilled water at a concentration of 50±5 g/L.
- Adjust the pH of the solution using acetic acid to a range of 3.1–3.3.
- Measure the pH at 25°C.
- Filter the prepared solution before use.
3. Copper-Accelerated Acetic Acid Salt Spray (CASS) Test Standard
- This is a rapid corrosion test recently developed abroad, conducted at 50°C.
- Dissolve chemically pure sodium chloride in distilled water at a concentration of 50±5 g/L.
- Add copper(II) chloride to the prepared saline solution in the specified ratio per liter, then mix thoroughly.
- Adjust the pH of the solution using acetic acid to a range of 3.1–3.3.
- Measure the pH at 25°C.
- Filter the prepared solution before use.
These standards ensure the reliability and accuracy of salt spray corrosion testing for evaluating material durability under harsh environmental conditions.
