ASTM E1851-21

5.1?This standard provides measurement procedures for determining the electromagnetic shielding effectiveness of durable rigid wall relocatable shielded enclosures. This standard specifies a method for comparing the shielded enclosure performance of structures provided by different suppliers. In addition, this standard is written to minimize variations in measured shielding effectiveness at a given frequency and test point regardless of test personnel, equipment, and test site. Therefore, the shielding effectiveness of a durable rigid wall relocatable shielded enclosure of any size from any supplier can be determined. This standard specifies a minimum set of measurements at a given frequency and a minimum set of frequencies to determine shielding effectiveness.

5.2?Source FieldsPerformance of a shielded enclosure is to be assessed for two source fields: magnetic and plane wave.

1.1?This test method covers the determination of the electromagnetic shielding effectiveness of durable relocatable shielded enclosures.

1.2?This test method is for use in the following frequency ranges: 140 kHz to 160 kHz, 14 MHz to 16 MHz, 300 MHz to 500 MHz, 900 MHz to 1000 MHz, and 8.5 GHz to 10.5 GHz. Specific test frequencies within these ranges are required (see 11.1.1 and 11.2.1). Additional measurements in the range of 10 kHz to 10.5 GHz may be performed. For specific applications, the frequency range may be extended from 50 Hz to 40 GHz. Appendix X1 provides guidance on selecting measurement frequencies.

1.3?This test method is not applicable to individual components such as separate walls, floors, ceilings, or shielded racks.

1.4?This standard may involve hazardous materials, operations, equipment, or any combination.

1.5?The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.6?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.