Working principle of salt spray test machine

The operating principles of a salt spray tester primarily include the following:

I. Salt Spray System

1. Salt Water Preparation: A sodium chloride solution of a certain concentration (usually around 5%) is injected into a salt water tank. This concentration simulates the composition of salt spray found in marine atmosphere or industrial environments.
2. Spray Generation: Compressed air draws salt water from the tank and atomizes it through a nozzle into fine salt spray particles. The nozzle design and pressure control adjust the particle size and spray volume of the salt spray, ensuring uniform application of the salt spray to the test specimen.

II. Temperature Control System

1. Heating: Salt spray testers typically feature a heating device to increase the temperature within the test chamber. The temperature is typically controlled between 35°C and 50°C. This temperature range accelerates the corrosive effects of salt spray on the specimen, simulating the high temperature and high humidity conditions found in real-world environments.
2. Refrigeration (Optional): Some high-end salt spray testers are also equipped with a refrigeration unit, enabling low-temperature salt spray testing. By lowering the temperature within the test chamber, the corrosion resistance of the specimen can be studied at low temperatures.

III. Humidity Control System

1. Saturated Air Preparation: Air is heated and passed through deionized or distilled water to achieve saturation. The relative humidity of saturated air approaches 100%, providing a high-humidity environment for salt spray testing.
2. Humidity Control: The flow rate and temperature of the saturated air can be adjusted according to test requirements to control the humidity within the test chamber. High humidity can accelerate the corrosive effects of salt spray on samples, particularly for metals, where humidity promotes electrochemical corrosion.

IV. Circulation System

1. Salt Spray Circulation: Salt spray particles are continuously circulated within the test chamber to ensure that all parts of the sample are exposed to the salt spray. The circulation system typically includes components such as fans, air ducts, and deflectors. The fans distribute the salt spray evenly within the test chamber.
2. Air Circulation: To maintain uniform temperature and humidity within the test chamber, an air circulation system is also provided. Air circulates between the heating or cooling unit, the saturated air drum, and the test chamber, maintaining stable environmental conditions within the chamber.

V. Sample Placement and Observation

1. Sample Placement: Place the test sample on a rack within the test chamber. The angle and position of the sample can be adjusted according to test requirements. The rack is typically made of corrosion-resistant materials such as tempered glass or PVC to prevent chemical reactions between the sample and the rack.
2. Observation Window: The test chamber is typically equipped with an observation window to allow observation of sample changes during the test. The observation window is typically made of transparent materials such as glass or acrylic, which offer excellent corrosion resistance and transparency.

In summary, a salt spray tester utilizes a salt spray system, temperature control system, humidity control system, and circulation system to simulate various harsh salt spray environments and test the corrosion resistance of test samples. This testing method helps companies assess the reliability and durability of their products in actual use environments, providing important evidence for product design, manufacturing, and quality control.

For more details, please contact Dongguan Zhongzhi Times Testing Equipment Co., Ltd.

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