Estimation of corrosion resistance of a metallic surface is very important. It helps in setting the quality standards and shelf life of the surface with respect to usage of the product and passage of time. Salt spray test is widely used to check corrosion resistance properties of the surface. In this test, the sample is placed in a chamber filled with salty fog. The salty fog initiates corrosion on the surface. The coating tends to protect the surface and resist corrosion. The test duration can vary from 24 hours to 72 hours to few days. The surface resistance will vary due to thickness, quality and technique of coating.

The salt spray chamber is maintained at a uniform temperature throughout the test process. The test procedure is defined in the testing standards. It advised to not disturb the conditions simulated for precise test results.

  • NaCl solution is used to create the salty fog. The fog has approximately 5% of salt content which is more than seawater. An atomiser is placed to in the centre of the chamber to create the fog and distribute uniformly.
  • The pH level of NaCl solution is to be maintained at 6.5 to 7 and spray rate is standardised as 1.0 to 2.0/ 80cm2/ / hour.
  • The chamber is protected with glass wool insulation to maintain the conditions and avoid any heat loss.
  • The test period is set in multiples of 24 hours. The severity of the test depends on the intended use of the sample.
  • The more critical an application, the more stringently test is performed.

Internal temperature of the chamber is maintained at 37°C. On the other hand, the humidity is 95%. Depending upon the internal standards and testing standards, the values can be varied.


Advantages of Using Fog Spray Chamber

  • Both treated and untreated samples can be tested. The test can be performed on ferrous and non-ferrous materials. Anything which is prone to corrosion in longer run can be tested.
  • The test is performed at a fast pace. Thus, years’ long behaviour of an object can be determined in few days. This is why it is called accelerated test.
  • Presto’s Salt Spray Chamberare available in multiple sizes. Apart from that, custom-made sizes can be procured as per the test requirements.
  • The test results are totally visual based. Thus, you do not require skilled workforce to perform the test. A sample can be tested on a pass / fail criterion.

For more information about salt spray chamber, you may contact our experts.