MIL-STD 202 Electronic and Electrical Component Parts

The MIL-STD-202 test standard is a Department of Defense document that establishes uniform methods for testing electronic and electrical component parts. This compliance testing includes basic environmental tests. The objective is to determine resistance to the deleterious effects of natural elements and conditions.

The environment military products experience can be extremely harsh. MIL-STD 202 testing simulates the environmental conditions surrounding military operations. This mechanical testing standard also provides guidance on physical and electrical tests.

The MIL-202 test standard utilizes the term “component parts” throughout the test document. Components are defined to include items such as capacitors, resistors, switches, relays, transformers, inductors, and others. This standard is intended to apply only to small component parts, weighing up to 300 pounds or having a root mean square test voltage up to 50,000 volts unless otherwise specifically invoked.

What are the Objectives of MIL-STD-202 Testing?

Military standard 202 was written to accomplish several objectives. These objectives include the following:

To specify suitable conditions obtainable in the laboratory that give test results equivalent to the actual service conditions existing in the field.
To obtain reproducibility of the results of tests. It should be noted that the tests described herein are not to be interpreted as an exact and conclusive representation of actual service operation in any one geographic location. This is true since the only true test for operation in a specific location is an actual service test at that point.
To describe in one standard the following:
- All of the test methods of a similar character which appeared in the various joint or single-service electronic and electrical component parts specifications.
- Those test methods which are feasible for use in several specifications.
- The recognized extreme environments. These particularly include temperatures, barometric pressures, etc., at which component parts will be tested under some of the presently standardized testing procedures.
- By so consolidating, these methods may be kept uniform and thus result in conservation of equipment, man-hours, and testing facilities. In achieving these objectives, it is necessary to make each of the general tests adaptable to a broad range of electronic and electrical component parts.
The test methods described herein for environmental, physical, and electrical tests shall also apply, when applicable, to parts not covered by an approved military specification, military sheet form standard, specification sheet, or drawing.

How is the Standard Organized?

MIL-STD-202 testing outlines classes of tests. The tests are divided into three classes. First, test methods numbered 101 to 199 inclusive, cover environmental tests. Second, the tests numbered 201 to 299 cover physical characteristics tests. Lastly, tests that are numbered 301 to 399 inclusive, cover electrical characteristics tests. Within each class, test methods are serially numbered in the order in which they are introduced into this standard.

Revisions of test methods are indicated by a letter following the method number. For example, the original number assigned to the moisture resistance test method is -106; the first revision of that method “-106A”, the second revision, “-106B”, etc. The following are all of the existing version of this test standard:

MIL-STD-202A
MIL-STD-202B
MIL-STD-202C
MIL-STD-202D
MIL-STD-202E
MIL-STD-202F
MIL-STD-202G
MIL-STD-202H

When applicable, test methods contained herein shall be referenced in the individual specification by specifying this standard with the dash number(-xxx) or this standard with the method number, and the details required in the summary paragraph of the referenced method.

To avoid the necessity for changing specifications which refer to this standard, the revision letter following the method number shall not be used when referencing test methods. The preferred wording to reference a method starting with revision H is “MIL-STD-202-106”; “MIL-STD-202, method 106” is still acceptable.

What is the Sequence of Tests?

The sequence of tests that follow is provided for guidance to specification writers to emphasize the

philosophy that parts be mechanically and thermally stressed prior to being subjected to a moisture resistance test. Within any of the three groups and subgroups, the order is preferred but not mandatory.

It is recommended that this sequence be followed in all new specifications and when feasible, in revisions of existing specifications. In the case of hermetically sealed parts, when a moisture resistance test is not required, a high sensitivity seal test may be used in lieu of the moisture resistance test.

MIL-STD 202 contains three test sequence groups.

Group I (all samples)

Visual Inspection
Mechanical Inspection
Electrical Measurements
Hermetic Seal Test (if applicable)

Group IIa (part of a sample)

Shock
Acceleration
Vibration

Group IIb (part of a sample)

Resistance to Soldering Heat
Terminal Strength
Thermal Shock

Group III (all units which have passed group II tests)

Moisture Resistance or Seal Test on Hermetically Sealed Parts

Why Is Keystone Compliance the Best MIL-STD-202 Test Lab?

Keystone Compliance provides an unmatched compliance testing experience. As an ISO-17025 certified MIL-STD-202 test lab, Keystone Compliance excels at assisting manufacturers in meeting these military testing requirements.

Our customers enjoy short lead times on scheduling and valuable engineering guidance throughout the test program. Communication is thorough and timely. Test reports are concise and delivered in an expedited manner once the testing is finalized.

Request a Quote to witness firsthand why so many companies partner with Keystone Compliance as their preferred MIL-STD-202 testing lab.

For more information about the specific MIL-STD-202 test methods, please click on one of the links below:

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