MIL-STD-907B: Engineering, Design, And Shielding Effectiveness of Expandable and Non-Expandable Shelters

MIL-STD-907B is a military standard that outlines the requirements for the measurement of the shielding effectiveness of electrical and electronic enclosures. The standard provides guidelines for the testing of these enclosures, ensuring that they provide adequate protection from electromagnetic interference (EMI) and radio frequency interference (RFI).

Shielding effectiveness is an important aspect of the development and manufacture of electronic and electrical equipment, as it helps to determine the ability of an enclosure to shield against unwanted electromagnetic emissions. The MIL-STD-907B standard specifies the test methods and procedures that should be used to measure shielding effectiveness, as well as the equipment and materials required for the tests.

Summary of MIL STD 907B Shielding Effectiveness Testing

MIL-STD-907B standard evaluates the development and design of rigid walled shelters. A few examples include:

  • Radio Room
  • Antenna Tower
  • Base Shelter
  • Power Shelter
  • Electrical Equipment Shelters
  • Instrument Shelter

Three lines of criteria are used in the design and engineering stage of effective shielding effectiveness:

  1. Achieve required performance and versatility by shelters.
  2. Minimize personnel man-hours to strike mobile shelters.
  3. Establish design standards of tactical shelters within the Agencies and Departments for the Department of Defense.

If a failure occurs, the Department of Defense would fail and remove the manufacturer from consideration.

According to the Department of Defense, there are five classes of shelters that would be categorized for applying this standard. The five categories are given a specific class:

  1. Class 1: Non-Expandable Shelters. These are shelters that have equivalent size and shape in any form of transportation necessary.
  2. Class 2: Expandable shelters. These are shelters that can expand in size and shape. However, they must fulfill an expansion ratio of 3-1 or less. Different shapes are also applicable.
  3. Class 3: Highly Expandable Shelters. These have expansion ratios larger than 3-1 to the transport size.
  4. Class 4: Knockdown shelters. Shelters that are reduced in height with exact items included inside for transportation.
  5. Class 5: Large Area Shelters. Shelters that are disassembled and packed in dedicated or general-purpose containers for shipment.

MIL-STD-907B follows the MIL-STD-285 standard, only with the following exceptions regarding test frequencies and test point locations:

  • Magnetic Field Frequencies: 150 kHz
  • Electric Field Frequencies: 200 kHz, 1 MHz, 18 MHz, 300 MHz
  • Plane Wave: 400 MHz, 1 GHz, 10 GHz
  • Test Point Locations: Following the MIL-STD-285 standard, one location per panel at the mid-point, and one location per vertical corner.

Scope of MIL-STD 907B Testing

One of the key benefits of MIL-STD-907B shielding effectiveness testing is that it helps to ensure the reliability and functionality of electronic and electrical equipment in the presence of electromagnetic interference. By providing a standardized and consistent approach to the testing of enclosures, the standard helps to ensure that electronic equipment is able to operate effectively and securely, even in challenging electromagnetic environments.

Another benefit of the MIL-STD-907B standard is that it provides a common reference for the testing and measurement of shielding effectiveness, which helps to ensure the compatibility and interoperability of electronic equipment across different platforms and systems. The standard also helps to ensure the security and reliability of military systems and networks, by helping to prevent the infiltration of unwanted electromagnetic emissions that could compromise the integrity of these systems.

Expert MIL-STD-907 Compliance Testing

MIL-STD-907B is an important military standard that provides guidelines for the testing and measurement of the shielding effectiveness of electrical and electronic enclosures. The standard helps to ensure the reliability and functionality of electronic and electrical equipment as well as the security and integrity of military systems and networks, by providing a consistent and standardized approach to the testing of these enclosures.

Keystone Compliance has the capabilities to test any size of enclosure to MIL-STD-907b. We have tested large items such as entire on-site installation buildings and small items that can be easily transported to our lab. In addition to MIL-STD-907 testing, Keystone has a full scope of expertise including environmental and package testing such as vibration, cold chain, and accelerated aging

Are you ready to partner with Keystone Compliance to determine the shielding effectiveness of your product when tested to the requirements of MIL-STD 907B? Let’s get started!

Diagram of MIL-STD-907 Testing

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