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AECTP 303 Low Temperature Testing

AECTP 303 Low-Temperature Climatic Testing

AECTP 303 evaluates the effects of low temperature on a material. As an ISO-17025 accredited environmental compliance test lab, we realize the importance of AECTP 300 climatic testing. Meeting low-temperature test requirements can be complex. We understand the challenges and guide companies through the process. 

Keystone’s engineers take a consultative approach throughout the entire test program. We expedite comprehensive reports shortly after the completion of the test. Our proven process helps avoid product launch delays. When products do not meet the requirements, we assist with the troubleshooting process. 

Ready to get started? Request a quote to see why so many companies partner with Keystone Compliance. Contact us to receive more information on AECTP 303 climatic testing.

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 303 Low-Temperature Compliance Testing

There are three main goals of AECTP 303 low-temperature compliance testing:

  1. To decide if the safety of a material is affected as a result of exposure to low temperatures.
  2. To determine if a material can be stored, manipulated, and operated within the specified requirements. This can occur during or after exposure to low temperatures that a material is expected to encounter during its life cycle.
  3. To determine if a material experiences physical damage during or after its exposure to low temperatures.

The AECTP 303 method is used when a material is deployed in regions in which the climatic conditions induce low temperatures.

The low-temperature AECTP 303 standard is also used in conjunction with shock and vibration tests. This will evaluate the effects of dynamic events on cold, embrittled material.

Limitations of the AECTP 303 test include:

  • This method is not intended to be used to simulate temperature-altitude effects experienced by aircraft-mounted equipment.
  • This method does not address temperature cycling through 0 C.
  • AECTP 303 does not address the effects of snow, ice, or wind.
  • This standard test method does not address the effects of frost. This is due to the fact that the test would require a controlled source of moisture.

Exposure to constant or cyclic low temperatures can either temporarily or permanently impair the operation of the material. This is done by changing the properties or dimensions of the material.


  • Phase changes
  • Dimensional changes
  • Distortion, binding, failure of bearings shafts, and packages
  • Failure of seals
  • Differential thermal contraction
  • Changes in physical properties. I.e. Modulus, strength, and elongation
  • Lubricant failure due to viscosity change
  • Failure of bonding materials
  • Stiffening of shock and vibration mounts
  • Difficulty of manipulation


  • Reduced rates of reaction:
    • Burning rates of explosives and propellants
    • Igniters failing to operate


  • Resistors and other components changing in value and life expectancy
  • Variations in circuit characteristics
  • Altering of operating and release margins of electrochemical devices
  • Batteries generating insufficient power
  • Breakdown due to shrinkage of insulation or potting
  • Changes in the performance of transformers
  • Excessive static electricity
  • Difficulty in obtaining or maintaining good grounding

AECTP 303 Low-Temperature Compliance Testing Procedures

Temperature and exposure are the most significant parameters for testing to AECTP 303. The test procedure must also specify the operational configuration of the unit under testing.

There are three test procedures in this test method: storage, operating, and manipulating. If applicable, all three tests can be performed.

Procedure I – Storage Test

The storage test procedure assesses the effects of storage of the material at low temperatures. This test can be carried out in two different ways:

  1. Exposure to a constant low temperature
  2. Exposure to cyclic low temperature (change of at least 9 C)

Procedure II – Operational Test

The AECTP 303 operation test assesses the effects of exposure to low temperatures on the operational performance of the material. In most cases, this test will be followed by a storage test. Additionally, the operational test can be preceded by or combined with the manipulation test.

Procedure III – Manipulation Test

For this test, the unit is exposed to the same temperatures as for the constant temperature operating test. The procedure is used to:

  • Test the suitability of the material for handling. More specifically, in operation, assembly, disassembly, and installation by personnel equipped to withstand cold.
  • To determine if a material can be assembled and disassembled at low temperatures safely without damage.

Expert AECTP 303 Low-Temperature Compliance Testing

In addition to AECTP 303 low-temperature testing, Keystone has a full scope of expertise including rain, fungus, and dust. Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling.

Have a question about AECTP 303 compliance testing? Contact us to discuss the best course of action.

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