Salt spray testing is also referred to as salt fog testing, salt corrosion testing, or simply salt spray chamber. It is one of the most common methods used to test materials and coatings for corrosion resistance. In salt spray testing, samples are placed in a salt environment to mimic the corrosive action of salt-rich air or water. The main purpose of salt spray test chambers is to determine the durability and resistance to corrosion of materials, especially metals and coatings. Several materials are frequently used in salt spray test setups.

1. Test Chamber Material:
The main component of a salt spray test chambers apparatus is the test chamber, where specimens are exposed to the corrosive environment. The chamber is typically made of materials that resist corrosion themselves. Common choices include non-reactive plastics, such as polypropylene or PVC (polyvinyl chloride), which do not degrade when exposed to salt spray.

2. Spray Nozzles and Piping:
The nozzles and piping through which the salt spray is delivered are typically made of materials that are resistant to corrosion. Stainless steel is a popular choice for these components due to its corrosion resistance, durability, and suitability for use in harsh environments.

3. Specimen Holders and Racks:
The specimens undergoing testing need to be securely held in the test chamber. Materials like stainless steel or other corrosion-resistant alloys are commonly used for specimen holders and racks. These materials ensure that the test setup itself does not introduce unwanted variables into the experiment.

4. Temperature and Humidity Controls:
The components responsible for maintaining the test chamber's temperature and humidity levels also need to resist corrosion. Materials like stainless steel are often employed for these components to ensure their longevity and reliability.

5. Seals and Gaskets:
To prevent leakage and maintain the controlled environment inside the test chamber, seals and gaskets play a crucial role. Materials with good resistance to corrosion, such as fluorocarbon elastomers (e.g., Viton), are commonly used for seals and gaskets in salt spray testing equipment.

6. Control Panel and Electronics:
The control panel and electronic components of the testing apparatus need protection from the corrosive environment. Enclosures made of materials like stainless steel or other corrosion-resistant alloys are used to shield these sensitive parts.

In summary, materials selected for salt spray test chamber equipment are chosen based on their resistance to corrosion, durability, and suitability for maintaining a controlled testing environment. Stainless steel and corrosion-resistant plastics are prevalent choices due to their ability to withstand the harsh conditions of salt spray testing over extended periods. These materials ensure that the testing apparatus itself does not introduce artifacts into the corrosion resistance evaluation of the specimens under examination.