ASTM E1851-04
(Test Method)Standard Test Method for Electromagnetic Shielding Effectiveness of Durable Rigid Wall Relocatable Structures
Standard Test Method for Electromagnetic Shielding Effectiveness of Durable Rigid Wall Relocatable Structures
SIGNIFICANCE AND USE
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.
Source Fields—Performance of a shielded enclosure is to be assessed for two source fields: magnetic and plane wave.
4.2.1 Magnetic Field Measurements—The attenuation provided by a shielded enclosure is assessed by using a local source to generate the near field. The magnetic field measurements are specified for two narrow frequency bands: 140 to 160 kHz and 14 to 16 MHz.
4.2.2 Plane Wave Measurements—The attenuation provided by a shielded enclosure is assessed by using a locally generated distant source or plane wave field. The plane wave measurements are specified for three narrow frequency bands: 300 to 500 MHz, 900 to 1000 MHz, and 8.5 to 10.5 GHz.
SCOPE
1.1 This test method covers the determination of the electromagnetic shielding effectiveness of durable relocatable shielded enclosures.
1.1.1 The intended application of this test method is for virgin shielded enclosures that do not have any equipment or equipment racks. It is recommended that tests be conducted before the interior finish work begins. However, the shield assembly including all enclosure penetrations shall be completed and required penetration protection devices shall be installed in accordance with the design specification. The test method can also be used on existing shielded enclosures after repair work is done to verify workmanship, but it may be necessary to remove equipment or equipment racks to gain access to a test area.
1.1.2 The test procedures delineated in this document are comprehensive and may require several days to complete for a room-size shielded enclosure. A user can apply this test method for a first article test that requires proof of concept and validation of design and fabrication technique. Appendix X2 provides guidance on choosing test points so shielding effectiveness tests on a room-size shielded enclosure may be completed in about one-half day for which it applies to shielded enclosures coming off an assembly line.
1.2 This test method is for use in the following frequency ranges: 140 to 160 kHz, 14 to 16 MHz, 300 to 500 MHz, 900 to 1000 MHz, and 8.5 to 10.5 GHz. Specific test frequencies within these ranges are required (see 10.1.1 and 10.2.1). Additional measurements in the range of 10 kHz to 10.1.5.1 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 the standard. The values in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E1851 – 04
Standard Test Method for
Electromagnetic Shielding Effectiveness of Durable Rigid
1
Wall Relocatable Structures
This standard is issued under the fixed designation E1851; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 1.4 This standard may involve hazardous materials, opera-
tions, equipment, or any combination.
1.1 This test method covers the determination of the elec-
1.5 The values stated in SI units are to be regarded as the
tromagnetic shielding effectiveness of durable relocatable
standard. The values in parentheses are for information only.
shielded enclosures.
1.6 This standard does not purport to address all of the
1.1.1 The intended application of this test method is for
safety concerns, if any, associated with its use. It is the
virgin shielded enclosures that do not have any equipment or
responsibility of the user of this standard to establish appro-
equipment racks. It is recommended that tests be conducted
priate safety and health practices and determine the applica-
before the interior finish work begins. However, the shield
bility of regulatory limitations prior to use.
assembly including all enclosure penetrations shall be com-
pleted and required penetration protection devices shall be
2. Referenced Documents
installed in accordance with the design specification. The test
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2.1 IEEE Standards:
method can also be used on existing shielded enclosures after
IEEE Std299-1997, IEEE Standard Method for Measuring
repair work is done to verify workmanship, but it may be
theEffectivenessofElectromagneticShieldingEnclosures
necessary to remove equipment or equipment racks to gain
IEEE StdC95.1-1991, IEEE Standard for Safety Levels
access to a test area.
with Respect to Human Exposure to Radio Frequency
1.1.2 The test procedures delineated in this document are
Electromagnetic Fields, 3 kHz to 300 GHz
comprehensive and may require several days to complete for a
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2.2 Military Standard:
room-sizeshieldedenclosure.Ausercanapplythistestmethod
MIL-STD-188-125, High Altitude Electromagnetic Pulse
for a first article test that requires proof of concept and
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(HEMP) Protection for Ground Based C I Facilities Per-
validation of design and fabrication technique. Appendix X2
forming Critical, Time-Urgent Missions
provides guidance on choosing test points so shielding effec-
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2.3 OSHA Standard:
tiveness tests on a room-size shielded enclosure may be
OSHA Regulation,29 CFR 1910, Department of Labor,
completed in about one-half day for which it applies to
July 1992
shielded enclosures coming off an assembly line.
1.2 This test method is for use in the following frequency
3. Summary of Test Method
ranges: 140 to 160 kHz, 14 to 16 MHz, 300 to 500 MHz, 900
3.1 Test Configuration—A transmitting antenna is con-
to 1000 MHz, and 8.5 to 10.5 GHz. Specific test frequencies
nected to an electromagnetic source set to a specific frequency
within these ranges are required (see 10.1.1 and 10.2.1).
and amplitude. A receiving antenna is placed a specified
Additional measurements in the range of 10 kHz to 10.1.5.1
distance from the transmitting antenna, and the received
GHz may be performed. For specific applications, the fre-
electromagnetic field level is recorded as a reference or
quency range may be extended from 50 Hz to 40 GHz.
calibration measurement. The transmitting antenna and elec-
Appendix X1 provides guidance on selecting measurement
tromagnetic source are placed outside the shielded enclosure.
frequencies.
Thereceivingantennaandassociatedtestequipmentareplaced
1.3 This test method is not applicable to individual compo-
inside the shielded enclosure. The transmitting and receiving
nents such as separate walls, floors, ceilings, or shielded racks.
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This test method is under the jurisdiction of ASTM Committee E06 on Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
Performance of Buildings and is the direct responsibility of Subcommittee E06.53 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331.
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on Materials and Processes for Durable Rigidwall Relocatable Structures. Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
Current edition approved Nov 1, 2004. Published November 2004. Originally Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098.
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approved in 1997. Last previous edition approved in 2002 as E1851–97. DOI: Available from Occupational Safety and Health Administration (OSHA), 200
10.1520/E1851-04. Constitution Ave., NW, Washington, DC 20
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