Salt spray test chamber is through the principle of "nuit from brine and atomization, uniform atomization degree, no phenomenon of blocking crystallization, can ensure the test continuous, compressed air through it on their way to the nozzle bubble column was wet, and air atomizing nozzle will corrosion solution into corrosive aerosol, the heater to keep the temperature in the cabinet in the cabinet.
After each test, the pH value of the collected spray solution should be adjusted to the specified pH value.There are three test methods for salt spray test chamber, and the pH value and adjustment method of each test method are different, OTS will explain for you in detail below:
1.Neutral salt spray test (NSS test)Test the pH of the solution should be adjusted to make the salt fog box to collect the spray solution pH value between 6.5 ~ 7.2, the pH measurement should be in 25 ℃ plus or minus 2 ℃ with suan meter measurement, also can use measuring accuracy is not greater than 0.3 the precision of the pH test paper for routine detection.Beyond the range, the analysis can be adjusted by adding pure hydrochloric acid, lv sodium oxide or sodium bicarbonate.Loss of carbon dioxide in solution during spray may result in pH changes.Corresponding measures should be taken, for example, heat the solution to more than 35 ℃, only into the instrument or by the new boiling water solutions, in order to reduce the amount of carbon dioxide in the solution, can avoid the change of pH value.
2.Acetate spray test (AASS test)Suan was added to the salt solution of the neutral salt spray test to ensure the pH value of the collected liquid in the salt spray test chamber was 3.1~3.3.If the pH value of the prepared solution is 3.0-3.1, the pH value of the collected solution is generally within the range of 3.1-3.3.PH value measurement should be in 25 ℃ plus or minus 2 ℃ acidity meter was used to measure, also can use measuring accuracy is not greater than 0.1 the precision of the pH test paper for routine detection.The pH of the solution can be adjusted using either ice or sodium oxide.
3.Copper accelerated b suan salt spray test (CASS test)According to the neutral salt spray test, copper lv was added to the salt solution, and its concentration was 0.26g/L 0.02g/L. The pH value of the solution could be adjusted by suan or sodium hydroxide.
The solution is filtered before use to prevent solid matter from clogging the nozzle