The salt spray Test Chamber is based on the principle of "atomize and atomize from salt water, the degree of atomization is uniform, and there is no blocking crystallization phenomenon", which can ensure that the test is carried out continuously, and the compressed air is moistened on the way into the nozzle bubble tower through it, and the air The atomizing nozzle converts the corrosive liquid into a corrosive aerosol, which keeps the heater at the temperature inside the cabinet.
After each test, the pH of the collected spray solution should be adjusted to the specified pH. There are 3 test methods in the salt spray Test Chamber, and the pH value and adjustment method of each test method are different, which will be explained. You detail below:
1. Neutral salt spray test (NSS test) should adjust the pH value of the solution so that the pH value of the spray solution collected in the salt spray box is between 6.5 and 7.2. When measuring, it is also possible to use the accuracy of pH test paper with a measurement accuracy not greater than 0.3 for routine detection. Outside this range, the analytical value can be adjusted by adding pure hydrochloric acid, lv sodium oxide or sodium bicarbonate. Carbon dioxide in the solution during nebulization may cause pH changes. Corresponding measures should be taken, for example, heating the solution above 35°C, heating only into the instrument or heating through a new boiling solution to reduce the carbon content of sulfur dioxide in the solution, and the change of pH value can be avoided.
2. Acetic acid spray test (AASS test) Add acid to the salt solution of the neutral salt spray test to ensure that the pH of the liquid collected in the salt spray Test Chamber is 3.1~3.3. When the pH value is 3.0-3.1, the pH value of the collected solution is generally in the range of 3.1-3.3. The pH value should be measured in a pH meter at 25°C plus or minus 2°C, or you can use pH test paper with low measurement accuracy and a routine test with an accuracy of no more than 0.1. The pH of the solution can be adjusted using ice or sodium oxide.
3. Copper Accelerated Alkali Salt Spray Test (CASS Test) According to the neutral salt spray test, copper lv is added to the salt solution, and its concentration is 0.26g/L to 0.02g/L. The pH of the solution can be adjusted with Suan or NaOH.
Filter the solution before use to prevent solid matter from clogging the nozzle
