Radiometrics Midwest Corporation provides shielding effectiveness and screening attenuation testing for enclosures, cabinets, materials, cables and other products requiring evaluation of electromagnetic shielding performance.
Shielding effectiveness testing determines how effectively an enclosure, cable, connector, material or other shielding system reduces electromagnetic energy passing through it. Radiometrics has extensive experience with shielding effectiveness, screening attenuation and transfer impedance measurements for military, industrial, electronic and specialized applications. Because results can vary significantly with the test method, fixture, setup and measurement technique, our engineers work with clients to select an appropriate measurement approach for the product and application.
Shielding Effectiveness Testing Capabilities
Radiometrics provides shielding effectiveness testing using methods appropriate for the product, material, enclosure and frequency range being evaluated.
Our capabilities include:
- Shielded enclosure testing
- Screening attenuation measurements
- Transfer impedance testing
- Cable and connector shielding evaluation
- Material and component shielding evaluation
- Engineering and developmental testing
- Investigation of shielding-performance problems
- Military and commercial applications
Radiometrics has dedicated shielded test environments that can be used for shielding effectiveness, transfer impedance and related EMC measurements.
IEEE 299 Shielding Effectiveness Testing
IEEE 299 provides standardized procedures for measuring the effectiveness of electromagnetic shielding enclosures.
Testing evaluates the attenuation provided by the shielded enclosure by comparing electromagnetic field levels under specified test conditions.
Radiometrics performs applicable IEEE 299 shielding effectiveness measurements within our accredited capabilities and can assist clients in developing an appropriate test program for the enclosure and frequency range being evaluated.
IEC 61726 Screening Attenuation Testing
IEC 61726 provides methods for evaluating the screening attenuation of cables, cable assemblies and related structures using reverberation chamber techniques.
Radiometrics performs applicable IEC 61726 measurements within our accredited capabilities for products requiring evaluation of electromagnetic screening performance.
Transfer Impedance Testing
Transfer impedance is an important measure of shielding performance for cables, connectors, conduits and other shielded structures.
Rather than simply measuring radiated field attenuation, transfer impedance characterizes the relationship between current on a shield and the resulting voltage or disturbance appearing on the protected side of the shielding structure.
Radiometrics has experience performing transfer impedance measurements for military, industrial and specialized EMC applications.
Military Shielding Applications
Shielding effectiveness and transfer impedance testing are particularly important for military and defense equipment where electromagnetic compatibility and susceptibility requirements can be demanding.
Radiometrics supports military EMC programs involving shielding performance as well as other applicable EMC testing.
A shielding effectiveness project can often be coordinated with additional military EMC measurements when a product requires a broader qualification program.
Enclosure Shielding Effectiveness
The shielding performance of an enclosure depends on considerably more than the material used to construct it.
Potential leakage paths can include:
- Doors and access panels
- Seams and joints
- Ventilation openings
- Cable penetrations
- Connectors
- Gaskets
- Grounding and bonding points
- Windows and displays
- Mechanical fasteners
Testing can help determine whether the completed enclosure provides the required shielding performance and can identify frequency ranges where shielding degradation occurs.
Cable and Connector Shielding
Cables and connectors can become significant electromagnetic coupling paths even when the primary equipment enclosure provides good shielding.
Shielding performance can be affected by cable construction, shield termination, connector design, bonding and installation.
Radiometrics can evaluate cable, connector and assembly shielding performance using an appropriate test method for the product and application.
Developmental Testing and Troubleshooting
Shielding effectiveness testing does not need to be limited to final qualification.
Developmental measurements can be used to compare materials, gaskets, seams, cable terminations, connectors and enclosure modifications before the final design is completed.
If a shielding system does not provide the expected attenuation, Radiometrics can work with the manufacturer’s engineering team to characterize the frequency ranges and physical features associated with the problem.
Where practical, modifications can be evaluated during the test program to determine whether they improve shielding performance.
Selecting the Appropriate Shielding Test Method
Shielding effectiveness results can depend significantly on the test method, test fixture, frequency range, equipment configuration and measurement environment.
A method appropriate for a large shielded enclosure may not be appropriate for a cable, connector, material sample or small electronic enclosure.
Radiometrics can review the product, shielding objective and applicable specification with the customer to help determine the appropriate measurement approach before testing begins.
Information Needed for a Shielding Effectiveness Quote
To help Radiometrics develop an appropriate test program and quotation, please provide the following information when available:
- Product or test-item description
- Applicable standard or customer specification
- Required frequency range
- Required shielding or attenuation level
- Test-item dimensions
- Enclosure, cable, connector or material construction
- Number and type of penetrations or interfaces
- Required test configurations or orientations
- Drawings or photographs of the test item
- Previous shielding effectiveness or transfer impedance data, when available
If the appropriate test method is uncertain, Radiometrics can review the application and help determine a suitable measurement approach.
Why Use Radiometrics for Shielding Effectiveness Testing?
Radiometrics has provided EMC testing and engineering services since 1983. Our experience includes shielding effectiveness, transfer impedance, military EMC testing and investigation of electromagnetic coupling and shielding problems.
Unlike laboratories focused primarily on routine emissions testing, Radiometrics maintains dedicated shielded test environments and engineering experience for specialized shielding measurements.
Schedule Shielding Effectiveness Testing
Contact Radiometrics to discuss shielding effectiveness, screening attenuation, transfer impedance, developmental testing, military applications, scheduling or quotation requirements.