Why Salt chamber?
Salt Spray Chambers is used to perform salt spray test also known as fog test. Salt spray test is an accelerated environmental corrosion test where samples / minerals are either continuously or sporadically exposed to a fine spray of saline solution used to evaluate the corrosion resistance of coatings, coatings or electrical connections.
The duration of the test depends on the corrosion resistance of the coating; the more resistant the paint, the longer the test without showing any signs of corrosion. Or salt spray test is a standard test method used to check the corrosion resistance of coated samples. The coating provides corrosion resistance to metal parts made of steel, zamak or brass.
Conditions for salt spray testing (these conditions are maintained for the duration of the test).
A water solution of 5% by weight is compressed by compressed air into a spray (also known as fog or mist) that is directed to a closed test chamber containing samples to be tested. Samples are located under the oscillating salt spray and therefore are not directly affected by it. This saltpipe created a "write off" on the samples under test at a rate of 1.0 to 2.0 ml / 80 cm² / hour. In general, unless otherwise specified, the pH of this fall must be neutral and controlled between 6.5 to 7.2. The salt spray filtration continues throughout the test. The duration of the test varies depending on the type of test sample and the intended application, but is usually given in multiples of 24 hours.
Generally, unless otherwise specified, the temperature of the test chamber must be controlled at 35 ° C and humidity should be maintained at 95-100% relative humidity.
Advantages of salt spray testing
- Short test duration The duration of the test is short compared to the natural environment, the cost is limited and a standard material is needed.
- Large samples can be checked. In the salt spray test, it is possible to examine very large samples, depending on the size of the salt spray chamber. Some of the rooms are very large in sizes so they allow to test the car.
- Simple to perform; salt spray testing is easy to implement and its results seem to be understandable to everyone immediately. The salt spray test only tests the corrosion resistance of the base material but can also show the effect of surface preparation on stainless steel resistance to atmospheric corrosion.
- Salt spray testing is a multi-material and can also be a common test for finishing materials and surfaces, due to the fact that roughness and wetness play a big role in the end result.