MIL-STD-461 is a U.S. military standard for Electromagnetic Interference (EMI) control in military systems. The standard outlines the requirements for EMI control and provides guidelines for the measurement of the shielding effectiveness of electronic enclosures. Shielding effectiveness is an important metric in the field of electromagnetic compatibility (EMC), as it determines the ability of a material or structure to block or reduce the transmission of electromagnetic energy.
MIL-STD-461 provides specific test procedures for measuring the shielding effectiveness of electronic enclosures, including radiated emissions and susceptibility testing. Radiated emissions testing measures the amount of electromagnetic energy that is transmitted from the system, while susceptibility testing measures the ability of the system to withstand external electromagnetic energy. The standard covers a range of frequencies, from 10 kHz to 40 GHz, and provides guidance on how to perform both conducted and radiated susceptibility tests.
Scope of MIL-STD-461 Shielding Effectiveness Testing
One of the main objectives of MIL-STD-461 is to ensure the reliability and functionality of military electronic systems. Electronic systems are becoming increasingly sensitive to EMI and RFI, and without adequate shielding, these systems may experience malfunctions, incorrect data readings, or system crashes. By measuring the shielding effectiveness of electronic enclosures, manufacturers and engineers can ensure that military electronic systems are protected from EMI and RFI and that they will operate correctly and reliably in their intended environment.
MIL-STD-461 is also important for ensuring the security and reliability of military electronic systems. In military and aerospace applications, shielding effectiveness is a critical factor in ensuring the compatibility and interoperability of these systems across different platforms and networks. By ensuring that electronic systems are adequately shielded, the risk of unauthorized access or interference can be reduced, and the security and reliability of these systems can be maintained.
The steps to complete MIL-STD-461 shielding effectiveness testing can vary depending on the specific requirements of the test and the equipment being tested. However, a general outline of the steps is as follows:
- Preparation: Before beginning the test, the test equipment, the electronic enclosure, and the test environment must be prepared. This includes calibrating the test equipment, preparing the test environment, and installing the electronic enclosure in the test environment.
- Conducted Susceptibility Testing: Conducted susceptibility testing is performed to evaluate the system’s response to external electrical interference. This test measures the susceptibility of the system to conducted electromagnetic interference, which is injected into the system through cables and power lines.
- Radiated Susceptibility Testing: Radiated susceptibility testing is performed to evaluate the system’s response to external electromagnetic interference. This test measures the susceptibility of the system to electromagnetic fields that are generated by external sources and propagate through the air.
- Radiated Emissions Testing: Radiated emissions testing is performed to evaluate the amount of electromagnetic energy that is transmitted from the system. This test measures the amount of electromagnetic energy that is generated by the system and radiates into the surrounding environment.
- Evaluation and Reporting: After the tests have been completed, the results must be analyzed and reported. This includes evaluating the shielding effectiveness of the electronic enclosure, analyzing the test results, and generating a report that summarizes the findings.
These steps provide a general outline of the steps involved in MIL-STD-461 shielding effectiveness testing. The specific steps and procedures may vary depending on the equipment being tested and the requirements of the test. It is important to follow the guidelines and procedures outlined in MIL-STD-461 when conducting shielding effectiveness testing to ensure accurate and reliable results.
MIL-STD-461 provides test limits for the measurement of shielding effectiveness of electronic enclosures in military systems. The test limits depend on the specific requirements of the test and the frequency range being tested.
For radiated susceptibility testing, the standard provides limits for the level of electromagnetic interference that the system must be able to withstand without degradation of performance or damage. The limits are specified in terms of field strength or power density, and are defined for different frequency ranges.
For radiated emissions testing, the standard provides limits for the amount of electromagnetic energy that can be transmitted from the system. The limits are specified in terms of field strength or power density, and are defined for different frequency ranges. The limits are intended to prevent interference with other electronic systems and to protect sensitive electronic equipment from harmful electromagnetic fields.
For conducted susceptibility testing, the standard provides limits for the level of conducted electromagnetic interference that the system must be able to withstand without degradation of performance or damage. The limits are specified in terms of voltage, current, or power, and are defined for different frequency ranges.
These test limits are specified in MIL-STD-461 and are designed to ensure the reliability and functionality of military electronic systems, as well as to protect these systems from electromagnetic interference. The specific test limits will depend on the requirements of the test and the equipment being tested, and it is important to follow the guidelines and procedures outlined in MIL-STD-461 when conducting shielding effectiveness testing.
Expert MIL-STD-461 Compliance Testing
Keystone Compliance has the capabilities to test any size of enclosure. 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 461? Let’s get started!
For more information on Keystone’s shielding effectiveness testing capabilities, please visit: www.keystonecompliance.com
