MIL- STD 202 Salt Spray Fog Test For Electronic Products
According to MIL-STD 202, environmental testing of electronic products is a critical step in ensuring their performance and reliability under natural factors and military application environments, including: salt spray fog test, thermal shock tests, vibration tests, etc., the standard provides a uniform test method for various components such as capacitors, resistors, switches, relays, etc., aimed at assessing their resistance to harmful environmental factors. Unless otherwise noted, this standard applies to small components weighing not more than 300 pounds or with test voltages not exceeding 50,000 volts. This paper will focus on salt spray fog test in environmental test.
Humidity test
Thermal shock
Sand and dust
Vibration testing
Pressure testing
1. salt mist chamber with bracket or fixed device;
2. A salt solution reservoir with a device for monitoring appropriate solution levels.
3. Device for atomizing salt solution, including suitable nozzle and compressed air supply.
4. Room heating device and control device.
5. A device for humidifying the air at a temperature higher than the indoor temperature.
In the salt spray corrosion test, the material selection and layout design of the test equipment are very important. The MIL-STD 202 standard states that the salt mist chamber and all its accessories shall be made of materials such as glass, hard rubber or plastic that are not susceptible to salt gas corrosion. At the same time, the parts in direct contact with the sample should also choose materials that will not cause electrolytic corrosion. The laboratory should be constructed and arranged so that condensation does not fall directly on the sample, but allows the atmosphere to flow freely and prevents the salt solution from returning to the reservoir. In addition, the test chamber should be equipped with an appropriate ventilation system to maintain an even distribution of salt spray and prevent pressure buildup. Proper heating equipment is also necessary to ensure that the test temperature remains stable. Only by meeting these key requirements can the salt spray corrosion test objectively reflect the performance of the sample in the actual use environment.
Use at least two clean fog collecting containers. One is the circumference of the test sample placed closest to any nozzle. The other is the circumference of the sample farthest from the nozzle. The containers are fixed, so they are not shielded from the specimen and therefore do not collect solution drops from the specimen.
When measured at the temperature of the exposed area, the solution thus collected will have a sodium chloride content of 4% to 6%. Check the specific gravity and quantity of the collected solution after each salt gas test. A suitable atomization effect is obtained in boxes less than 12 cubic feet in volume under the following conditions:
 solution with temperature_.png)
JOEO is the leading manufacturer of salt spray test chambers in China, and our test engineering is able to provide salt spray certification for commercial, military and aerospace products. If you would like to learn more about MIL-STD-202 compliance testing methods, please contact us as soon as possible.
Type of test
Salt spray fog testHumidity test
Thermal shock
Sand and dust
Vibration testing
Pressure testing
Purpose of salt spray testing
The salt spray test is to place the sample in a fine mist of salt solution to simulate the effect of the coastal atmosphere on the metal, and there is little direct relationship between corrosion resistance in the salt atmosphere and corrosion resistance in other media, even in the so-called "Marine" atmosphere and seawater. However, some idea of the relative service life and behavior of different samples of the same (or closely related) metal or protective coating - base metal combinations at Marine and coastal exposure sites can be obtained through salt atmosphere testing.Test equipment
Equipment for salt mist chamber shall include:1. salt mist chamber with bracket or fixed device;
2. A salt solution reservoir with a device for monitoring appropriate solution levels.
3. Device for atomizing salt solution, including suitable nozzle and compressed air supply.
4. Room heating device and control device.
5. A device for humidifying the air at a temperature higher than the indoor temperature.
In the salt spray corrosion test, the material selection and layout design of the test equipment are very important. The MIL-STD 202 standard states that the salt mist chamber and all its accessories shall be made of materials such as glass, hard rubber or plastic that are not susceptible to salt gas corrosion. At the same time, the parts in direct contact with the sample should also choose materials that will not cause electrolytic corrosion. The laboratory should be constructed and arranged so that condensation does not fall directly on the sample, but allows the atmosphere to flow freely and prevents the salt solution from returning to the reservoir. In addition, the test chamber should be equipped with an appropriate ventilation system to maintain an even distribution of salt spray and prevent pressure buildup. Proper heating equipment is also necessary to ensure that the test temperature remains stable. Only by meeting these key requirements can the salt spray corrosion test objectively reflect the performance of the sample in the actual use environment.
How should the test chamber be operated?
During the specified test duration, a salt spray with a minimum temperature of 95°F passes through the chamber. The exposed area of the chamber is maintained at a temperature of 95°F±5°F. Containers placed in exposed areas should collect 0.5-3.0 ml of solution per 10 cm diameter collection area per hour. This is a way to test whether the conditions in the exposed area are suitable.Use at least two clean fog collecting containers. One is the circumference of the test sample placed closest to any nozzle. The other is the circumference of the sample farthest from the nozzle. The containers are fixed, so they are not shielded from the specimen and therefore do not collect solution drops from the specimen.
When measured at the temperature of the exposed area, the solution thus collected will have a sodium chloride content of 4% to 6%. Check the specific gravity and quantity of the collected solution after each salt gas test. A suitable atomization effect is obtained in boxes less than 12 cubic feet in volume under the following conditions:
- Nozzle pressure from 12 to 18 pounds per square inch.
- Hole diameters range from 0.02 to 0.03 inches.
- Every 24 hours, atomize 3 quarts of desalting solution per 10 cubic feet of tank volume.
 solution with temperature_.png)
What is the appropriate duration of the MIL-STD 202 salt atmosphere test?
Unless otherwise specified, tests will run continuously for a specified period of time. Or it will run until a clear indication of failure is observed. There shall be no interruption except for the adjustment of the instrument and the examination of the sample. The length of the salt atmosphere test is indicated in one of the following test conditions.| Test Condition | Length of Test (Hours) |
| A | 96 |
| B | 48 |
| C | 24 |
| D | 240 |
JOEO is the leading manufacturer of salt spray test chambers in China, and our test engineering is able to provide salt spray certification for commercial, military and aerospace products. If you would like to learn more about MIL-STD-202 compliance testing methods, please contact us as soon as possible.
