Select Page
AECTP 302 High Temperature Testing

AECTP 302 High-Temperature Climatic Testing

AECTP 302 evaluates the effects of high temperature on a material. As an ISO-17025 accredited environmental compliance test lab, we realize the importance of AECTP 302 compliance testing. Meeting high-temperature test requirements can be difficult. We understand the challenges and guide companies through the process. 

Keystone provides the peace of mind that all of your needs will be met. We have a reputation for helping customers achieve their environmental product certifications. When products do not meet the requirements, we assist with the troubleshooting process.

Request a quote to see why so many companies partner with Keystone Compliance. Ready to get started? We are. Contact us to see why so many companies work with Keystone each year to achieve their environmental standard test needs.

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 actual 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 302 High-Temperature Environmental Testing

There are three main objectives to these tests.

  1. To determine if a material is safe to handle and/or operate during and following exposure to high temperatures.
  2. To determine if a material can be stored and operated during and following exposure to high temperatures that it is expected to encounter during its service life.
  3. To determine if a material experiences physical damage during and/or after experiencing high temperatures.

High temperatures can be caused by nearby sources of heat, direct solar loading, or indirect solar loading.

AECTP 302 does not address the actinic effects of solar radiation. Nor does the test address the high gradients caused by transient events.

High temperatures can either temporarily or permanently impair the performance of the test item. This is done by changing the physical properties or dimensions of its construction materials. Examples of degradation that can occur as a result of high temperature includes the following:


  • Melting and exudation
  • Dimensional changes
  • Distortion, binding, failure of bearings, shafts, and packaging
  • Gaskets and seals deteriorating
  • Development of internal pressure
  • Changes in physical properties such as modulus, strength, and elongation
  • Lubricants becoming less viscous


  • Increased rates of diffusion
  • Increased rates of reaction
  • Failure of chemical agent protection
  • Release of vapors leading to corrosion


  • Resistors and other components changing in value and life expectancy
  • Variations in circuit characteristics, electric, electronic, or optical
  • Failure of transformers, electromechanical devices, etc.
  • Altering of operating/release margins of electromechanical devices
  • Static electricity when humidity is low

AECTP 302 High-Temperature Test Procedures

The test durations for AECTP 302 high-temperature testing are expressed in numbers of 24-hour cycles.

There are three test procedures included in this test method.

Procedure I This procedure assesses the effects of storage of the material at high temperatures upon its performance and safety in use. The storage situation is assessed with respect to:

  • The climatic zone concerned or the included conditions caused by any heat source.
  • Whether the service environment is cyclic or steady state.

Procedure II – Procedure II evaluates the effects of exposure to high temperatures on the operational performance of the material and upon safety in use. This test is generally preceded by a storage test. The test can be carried out in different ways:

  • Exposure to cyclic temperatures with the test item operating continuously
  • Exposure to cyclic temperature with the test item operating after its response temperature has peaked
  • Exposure to constant temperature with the test item is operational either throughout the test or after temperature stabilization

Procedure III – This is used if the material is expected to withstand the heat from exposure in the open in hot climates and still be able to perform without degradation both during and after exposure. The solar radiation test is used when the heating caused by solar radiation is unknown.

Expert AECTP 302 High-Temperature Environmental Compliance Testing

Our team strives to give our customers more time and energy on product development instead of testing. In addition to environmental AECTP compliance testing, Keystone has a full scope of expertise including freeze-thaw, solar radiation, and ingress protection (IP Code). Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling. 

Ready to get started? We are. Contact us to see why so many companies work with Keystone each year to achieve their environmental standard test needs.

For more information on AECTP 300 testing, please follow the links below: