Caltech Engineering Services manufactures salt spray testing instrument. Salt spray test is also called as Fog Test. This is an accelerated environmental corrosion test in which metal specimens are exposed either continuously or intermittently to a fine mist of salt-water solution used to evaluate the resistance to corrosion of paints, coatings, or electrical connections. The appearance of corrosion products (oxides) is evaluated after a period of time. Test duration depends of the corrosion resistance of the coating; the more corrosion resistant the coating is, the longer the period in testing without showing signs of corrosion.