Salt water spray tests are often used to evaluate the corrosion resistance performances of metal materials and inorganic and organic plate coatings applied on metal materials. Neutral salt water spray test methods are explained here.

(1) Test equipment

The system is comprised of Salt water spray device, Specimen holder, temperature controllable spray chamber, Air saturator that saturates the test environment air with water. Required conditions for the test equipment are as follows.

	1.	The spray equipment is to be of Spray tower or Nozzle type.
	2.	The spray chamber is to be 0.2m3 or more.
	3.	The chamber ceiling or the cover is designed not to drip the test solution on the specimen.
	4.	The equipment is to be corrosion resistant.
	5.	The chamber environment is not to be affected by the external air, and the solution dripped from the specimen is not to be re-deposited on the specimen.
	6.	The test specimen can be held in prescribed angles.
	7.	Two or more spray liquid collectors with horizontal collection area of 80cm2 are to be provided.

(2) Test specimen

	1.	To be 70×150×1.0 or 60×80×1.0 flat plates, but they can also be of materials agreed upon by the parties involved.
	2.	The metal or plated metal specimens are to be properly cleaned.
	3.	Cut sections of the specimen are to be protected with tape, paint, paraffin, etc.
	4.	The specimen during the test is to be held at 20±5° in relation to the vertical line.
	5.	The positioning and spacing of the test specimens are not to prevent free falling of the spray, and the solution dripped from the specimen is not to fall on other specimen.

(3) Testing salt water solution

The solution is to be adjusted to salt concentration of 40g/L by dissolving class1 sodium chloride reagent in deionized water, with a specific gravity of 1.0250~1.026 at 25℃.

(4) Air supply

The compressed air used to spray the salt water solution is to be kept at 0.098±0.01Mpa.

(5) Spray chamber condition

	1.	Spray chamber and test solution reservoir is to be at 35±2℃.
	2.	The spray is to be of free fall, and not to be directly sprayed on the test specimen.

(6) Post testing handling of test specimen

	1.	Test specimen is to be removed carefully.
	2.	Immediately water wash at a room temperature and dry in order to remove the salt from surfaces.
	3.	Corrosion born products are removed by mechanical means such as brushing or chemical means.

(7) Judgment method (Listed elsewhere)

	1.	Area method: By Rating Number Evaluation.
	2.	Weight method: Weight variations before and after the test.