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AECTP 309 Salt Spray Testing

AECTP 300 Method 309 Salt Fog Compliance Testing

AECTP method 309 salt fog testing evaluates the effects of aqueous salt atmospheres. As an ISO-17025 accredited environmental compliance test lab, we realize the importance of salt fog compliance testing. Meeting the environmental AECTP 300 requirements can be difficult. We understand the challenges and guide companies through the process. 

Keystone’s engineers take a consultative approach throughout the entire test program. Furthermore, we have a reputation for helping customers achieve their environmental product certifications. Our proven process helps avoid product launch delays. When products do not meet the requirements, we assist with the troubleshooting process.

Request a quote to receive testing services tailored to your specific requirements. Have a question about our AECTP climatic compliance testing capabilities? Contact us to discuss the best course of action.

Summary of AECTP 300 Environmental Climatic Compliance Testing

The AECTP 300 standard is intended to be used in conjunction with four other AECTP test standards (AECTP 100, 200, 400, and 500). Furthermore, the AECTP standard provides advice for preparing environmental test specifications, plans, and procedures.

Additionally, AECTP 300 evaluates climatic environments. These environments can occur individually or in combination with other climatic or mechanical environments.

The AECTP 300 tests outlined provide exposure to simulated conditions from which a degree of confidence can be established. 

During testing, the configuration used for the selected test should be the configuration used within the unit’s life cycle. As a minimum, the following is considered: 

  • In the shipping/storage container or transit case.
  • Protected or unprotected.
  • In its normal operating and thermal configuration.
  • Modified with kits for special applications.

Any of the following will be classified as a failure:

  • A deviation of monitored functional parameter levels beyond acceptable limits.
  • Nonfulfillment of safety requirements or the development of safety hazards.
  • Nonfulfillment of specific test item requirements.
  • Changes to the test item that could prevent it from meeting its intended service life or maintenance requirements.

Scope of AECTP 309 Salt Fog Compliance Testing

The AECTP 309 salt fog test evaluates the effects of a salt atmosphere on a material. The main reason for using method 309 is when testing coatings and finishes on material. Additionally, method 309 salt fog testing can be used to locate potential design problems. For example, incompatible materials.

The effects of exposure to salt fog can be divided into three categories.


  • Clogging or binding of moving parts of mechanical components and assemblies
  • Blistering of paint as a result of electrolysis


  • Corrosion due to an electrochemical reaction
  • Accelerated stress corrosion
  • Formation of acidic/alkaline solutions following salt ionization in water


  • Impairment of electrical equipment due to salt deposits
  • Production of conductive coatings
  • Attack of insulating materials and metals

AECTP Method 309 Salt Fog Test Procedures

Salt fog testing is limited to the salt concentration, test duration, the cycling of exposure and drying periods, and the salt composition.

The configuration and orientation of the test item are important considerations when determining the effect of the environment on the test. Generally, the test item is oriented as it would be during storage, shipment, or use. Other configurations also include:

  • In a shipping/storage container or transit case.
  • Outside of its shipping/storage container but provided with an effective environmental control system.
  • Outside of its shipping/storage container and set up in its normal operating mode.
  • Modified with kits for special applications or to compensate for mating components.


With the test item installed in the chamber, the temperature is adjusted to 35 C. The unit is conditioned for at least 2 hours. Next, the salt solution is continuously sprayed for 24 hours.

The test unit is then dried at standard ambient temperatures with a relative humidity of 50%. For the best test results, the amount of handling of the test item is minimized.

Once a specified number of cycles have been completed, the unit is visually inspected for any changes.

Expert AECTP 309 Salt Fog Compliance Testing Lab

In addition to environmental salt fog and climatic testing, Keystone has a full scope of expertise including vibration, shock, and fungus resistance. Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling. Our team strives to give our customers more time and energy on product development instead of testing. 

Contact us to receive more information on AECTP salt fog environmental testing.

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