Defense Standard 00-035 Part 3: Environmental Testing

The Defense Standard 00-035 evaluates the integrity of material when subjected to various environmental conditions. As a certified Defense Standard and ISO 17025 lab, we realize the importance of environmental compliance testing. Meeting the DEF STAN 00-035 compliance testing requirements can be difficult. Keystone Compliance understands the challenges and guides companies through the process. 

What sets us apart from other NRTLs is that when products do not meet the requirements, we continuously assist with finding solutions. Our pricing is competitive and we offer volume discounts. Keystone proudly has a reputation for helping customers achieve their DEF STAN 00-035 product certifications. 

Request a quote to see why so many companies partner with Keystone Compliance. Have a question about our defense standard compliance testing capabilities? Contact us or call (724) 657-9940 and we will determine the best course of action.

Summary of Defense Standard 00-035 Part 3

The Defense Standard (DEF STAN) 00-035 Part 3 provides test methods to reproduce relevant environments’ effects. The DEF STAN 00-035 Part 3 test method is grouped into sections relating to commonly encountered environments. These sections are as follows:

• DEF STAN 00-035 Part 3: MECHANICAL
• DEF STAN 00-035 Part 3: CLIMATIC
• DEF STAN 00-035 Part 3: CHEMICAL

More specifically, the DEF STAN 00-035 test methods are used to validate a material’s ability to withstand the effects of specific environments.

The following should be noted:

• The standard is not intended to be used in isolation but in conjunction with other parts.
• The anticipated life cycle of the material and changes in the material’s ability to withstand the effects of specific environments.
• These test methods are intended to reproduce the effects of relevant environments. They do not necessarily duplicate actual environmental conditions.

DEF STAN 00-035 General Testing Guidelines

Conditioning

General laboratory conditions are used when no other conditions are specified. Variations in the temperature and humidity are kept to a minimum during these DEF STAN 00-035 part 3 tests. For large specimens, the laboratory temperatures can be slightly extended.

• Temperature: 15 C to 35 C
• Air Pressure: 86 kPa to 106 kPa
• Relative Humidity: 65%

All specimens, whether large or small, are pre-conditioned to ensure the equipment begins the test in the condition closest to its natural environment. This will also ensure test repeatability.

High-temperature conditioning is known to accelerate the chemical aging of certain materials. This may cause significant detrimental effects. Limits are applied to the total pre-conditioning period when test material may be degraded by exposure to high temperatures.

When testing temperature modifying materials, low velocity forced air circulation is used. Two methods can be employed. Both require that the heat dissipating specimen is subject to temperature conditioning for a sufficient period to achieve temperature stability.

Mounting of Test Specimens

This portion of the standard assists when material mounting requires the use of generic or special purpose apparatus, jigs, or fixtures. The mounting of a specimen should be specified within the test program.

When mounting a specimen, the unit should simulate the installation arrangements that exist in its normal service use. More specifically, unrepresentative orientations, structural frames, etc. that could influence the outcome of the test should be minimized.

Mounting of Specimens for Mechanical Testing. For vibration, shock, and acceleration testing, the mounting is such that the specimen can be loaded or excited in each of the specified test axes. It is necessary to use different test fixtures for each axis.

When gravitational force is prevalent, the specimen is mounted so that the gravitational force acts in the same direction as it would in operational use.

Ideally, materials intended for use with vibration or shock isolation systems are tested with isolators in position.

Mounting of Specimens for Climatic Testing. Many of the climatic test procedures within DEF STAN 00-035 specify a method of mounting a specimen. Where this is not the case, the method is specified within the test program.

If more than one specimen is subjected to temperature testing in the same chamber, all specimens must experience the same test temperatures. The specimen must have identical mounting conditions.

When assessing heat-dissipating specimens or the effects of thermal conduction, the test specification will define the thermal characteristics of the in-service specimen mounting.

Examination and Performance Evaluation

The examination and performance evaluation is required before, during, and after testing. This is carried out to assess whether any degradation has occurred. Proper evaluations include the following.

• Visual examination
• Functional tests
• Performance tests
• X-ray, radiographic examination
• Sealing evaluation
• Non-destructive tests
• Metrology
• Physical tests – tensile properties, hardness, toughness, etc.
• Chemical tests

Before testing, the specimen is evaluated to provide baseline information by the relative procedures. Generally, the specimen must either be operated continuously or intermittently and allowed to stabilize before the evaluation is started.

Expert DEF STAN 00-035 Regulatory Compliance Testing Lab

Our team strives to give our customers more time and energy on product development instead of testing. Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling. In addition to DEF STAN 00-035 testing, Keystone has a full scope of expertise including shielding effectiveness, mechanical, climatic, EMC/EMI, and package testing. 

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