Salt spray test chamber test potion configuration method

Salt spray test chamber, salt spray machine, salt spray testing machine potion how to match? Commonly known as the salt spray machine "viscera" is mainly composed of: chamber, spray device, nozzle, liquid supply pipe, compressed air supply catheter and air humidification, support sample device.

Salt spray machine chamber: The chamber of salt spray testing machine shall be able to be heated and maintain pressure balance, and shall be equipped with measurement and control sensors to control the test temperature. The SS and ASS tests in the closed chamber are (35±2)℃, and the CASS tests are (50±2)℃. The test container needs a small volume of 400 L and can ensure that the spray condensed droplets do not drip off the top or side walls and prevent the sample from reaching the spray. After spraying, the test solution should not be reused. The effective space of the test is limited to the part outside the nozzle in the chamber where there is a uniformly verifiable spray diffusion range.

1. The preparation of salt spray machine test liquid of Farui Instrument: dissolve test grade chloride in distilled water (or water with total dissolved solids less than 200 ppm), and prepare the test liquid with a concentration of 5±1%. After spraying the test liquid at 35℃, the PH value of the collected liquid should be 6.5~7.3. And before spray, the test liquid can not contain floating matter.

Note (1) : Sodium chloride can not contain copper nickel impurity, solid sodium iodide content is less than 0.1%. Because the impurity may contain corrosion inhibitors, the total impurity content must be less than 0.3%.

(2) : The specific gravity of test liquid measured at 33~35℃ should be 1.0258~1.0402, and the specific gravity measured at 25℃ should be 1.0292~1.0443. The concentration of the test solution may also be calibrated by the silver nitrate drop determination method or other methods.

(3) : The pH value of the test solution shall be adjusted with a dilute solution of hydrochloric acid or sodium hydroxide of test grade, and measured by a pH meter or other reliable method. · Since the water in which the test solution is prepared contains carbon dioxide, the solubility of carbon dioxide in the water will affect the pH value of the solution with the change of temperature, the pH value shall be carefully controlled. ·pH value can be adjusted by any of the following methods:

① Prepare the test liquid at room temperature, · spray at 35℃, because of the rise in temperature, some carbon dioxide will escape from the solution and increase the pH value. Therefore, when preparing the test liquid at room temperature, the pH value should be adjusted within 6.5. Only then can the pH value of the collected liquid be between 6.5 and 7.2.

② Before pH value adjustment, the test solution was boiled and then cooled to 35℃, or maintained at 35℃ for 48 hours. The pH value so adjusted will not change much when sprayed at 35℃.

③ First heat the water to 35℃ above, to remove the dissolved carbon dioxide, and then modulate the test solution and adjust the pH value, so at 35℃ spray, the adjusted pH value will not change too much

: In order to avoid blockage of spray nozzle, the test liquid should be filtered or carefully poured into the brine bucket at an Angle, or a glass sieve should be installed at the front of the spray suction pipe for filtration.