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DO-160-Section-21-Emission-of-RF-Energy

MIL-STD-810B Environmental Engineering Considerations and Laboratory Tests

MIL-STD-810B is a military test standard for environmental testing. The standard was adopted on June 23, 1964. This version superseded MIL-STD-810, which was enacted on June 14, 1962. The title of the standard is Military Standard Environmental Test Methods for Aerospace and Ground Equipment.

What was the purpose of MIL STD 810B?

Military standard 810B establishes uniform environmental test methods for determining the resistance of equipment to the effects of natural and induced environments. These environments are common to military operations. The test methods contained within this environmental test standard outline specific environmental conditions.

These conditions must be recreated by a MIL-STD-810 testing lab. The objective is that the recreation occurs and the product continues to operate in a satisfactory manner even after being exposed to these conditions. When that occurs, there is a high degree of confidence that the item could survive the field environment during its expected service life.

The tests described within the MIL-810-B test standard are not to be interpreted as an exact and conclusive representation of actual service operation

How is the MIL-STD-810B test standard organized?

The standard contains 18 test methods. These test methods apply broadly to all items of aerospace and ground equipment. The exceptions are air frames and primary power plants. The test methods generally represent the extreme conditions which usually constitute the minimum acceptable conditions.

The environmental testing standard does state that when it is known that the equipment will encounter conditions more severe or less severe than the environmental levels stated, the testing may be modified by the individual equipment specifications.

What are the requirements of the test chambers?

Temperature testing is a major component of MIL-STD-810-B testing. Of the 18 different test methods included in the standard, five of them involve temperature and humidity. These test methods include testing for high temperature, low temperature, temperature shock, temperature & altitude and humidity.

To ensure accuracy and consistency, the test spec spells out specific requirements. One requirement involves defining the volume of the test chamber. The requirement is that the volume of the test chamber be such that the bulk of the item under test will not interfere with the generation and maintenance of test conditions.

Another defined topic is the heat source. The heat source of the test faciIity must be located so that radiant heat will not fall directly on the test item. There is one exception. This exception is when application of radiant heat is one of the test conditions.

An additional defined topic is the location of temperature sensors. Unless otherwise specified, thermocouples or equivalent temperature sensors utilized to determine or control the specified chamber temperature shall be centrally located within the test chamber. This is a best efforts requirement. They should ideally be located in the return air stream and baffled, or otherwise protected against direct impingement of supply air and against radiation effects.

What is the test sequence of 810B testing?

The selection of environmental test methods is based on a consideration of the environments which the equipment will experience. When more than one method has been selected, a sequence of testing should be specified. The test standard provides advisory information on the applicability of the various test methods and recommended test sequences.

Are there tolerances of test conditions?

MIL-STD-810 B permits the following tolerances of test conditions. These tolerances are exclusive of the accuracy of instruments. Temperatures can be plus or minus two degrees Celsius or 3.6 degrees Fahrenheit.

Relative humidity can be plus 5 percent relative humidity and minus zero percent. Atmospheric pressure can be plus or minus 5 percent or 0.06 inches of mercury, whichever provides the greatest accuracy. If measured by devices such as ion gauges the tolerance is plus or minus 10 percent.

Vibration amplitude has acceptable tolerances as well. For sinusoidal vibration, the tolerance is plus or minus 10 percent. For random vibration, the tolerance is plus or minus 30 percent. In acceleration testing, the acceptable tolerance is plus or minus 10 percent.

Keystone Compliance is a leader in the testing of military and aerospace products. Our scope of accreditation includes all versions of MIL-STD-810. This document covers MIL-STD-810B. For more information about the other versions of this military standard, please click on one of the links below:

As an ISO-17025-accredited test lab, Keystone Compliance is accredited to complete a full MIL-STD-810B test program. Our test facility includes nearly 10 EMC test chambers, several shakers, dozens of climatics chambers and other necessary equipment.

In addition to environmental testing, we also have a full scope of EMC/EMI testing. Our capabilities include shielding effectiveness, ESD, lightning, HEMP and many other types of EMC testing. Our lab features seven EMC test chambers. We also have a reverberation chamber. We also provide expert EMC site surveys.

Lastly, we are also an ISTA-accredited package testing lab. We offer full package testing capabilities through our Keystone Package Testing subsidiary. In addition to ISTA and ASTM, we also are one of the few labs approved to complete Amazon package testing.

We take a consultative approach and assist our customers throughout the entire test program. If failures arise, we assist in isolating them and finding potential solutions. Contact us to see why so many manufacturers partner with Keystone Compliance.

The MIL-STD-810B test specification includes the following test methods and sections. For more information on each type of testing, please click on the associated links.