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ASTM D4935-10

(Test Method)

Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar Materials

Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar Materials

SIGNIFICANCE AND USE
This test method applies to the measurement of SE of planar materials under normal incidence, far-field, plane-wave conditions (E and H tangential to the surface of the material).
The uncertainty of the measured SE values is a function of material, mismatches throughout the transmission line path, dynamic range of the measurement system, and the accuracy of the ancillary equipment. An uncertainty analysis is given in Appendix X1 to illustrate the uncertainty that may be achieved by an experienced operator using good equipment. Deviations from the procedure in this test method will increase this uncertainty.  
Approximate near-field values of SE may be calculated for both E or H sources by using measured values of far-field SE. A program may be generated from the source code in Appendix X2 that is suitable for use on a personal computer.
This test method measures the net SE caused by reflection and absorption. Separate measurement of reflected and absorbed power may be accomplished by the addition of a calibrated bidirectional coupler to the input of the holder.
SCOPE
1.1 This test method provides a procedure for measuring the electromagnetic (EM) shielding effectiveness (SE) of a planar material for a plane, far-field EM wave. From the measured data, near-field SE values may be calculated for magnetic (H) sources for electrically thin specimens. , Electric (E) field SE values may also be calculated from this same far-field data, but their validity and applicability have not been established.
1.2 The measurement method is valid over a frequency range of 30 MHz to 1.5 GHz. These limits are not exact, but are based on decreasing displacement current as a result of decreased capacitive coupling at lower frequencies and on overmoding (excitation of modes other than the transverse electromagnetic mode (TEM)) at higher frequencies for the size of specimen holder described in this test method. Any number of discrete frequencies may be selected within this range. For electrically thin, isotropic materials with frequency independent electrical properties of conductivity, permittivity, and permeability, measurements may be needed at only a few frequencies as the far-field SE values will be independent of frequency. If the material is not electrically thin or if any of the parameters vary with frequency, measurements should be made at many frequencies within the band of interest.
1.3 This test method is not applicable to cables or connectors.
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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

Status
Historical
Publication Date
30-Apr-2010
ICS
17.220.20 - Measurement of electrical and magnetic quantities
Technical Committee
D09 - Electrical and Electronic Insulating Materials
Drafting Committee
D09.12 - Electrical Tests
Current Stage
Ref Project

Relations

Replaces
ASTM D4935-99 - Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar Materials (Withdrawn 2005)
Effective Date
01-May-2010
Replaced By
ASTM D4935-18 - Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar Materials
Effective Date
01-May-2018
Referred By
ASTM B904-00(2021) - Standard Specification for Autocatalytic Nickel over Autocatalytic Copper for Electromagnetic Interference Shielding
Effective Date
01-May-2010

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ASTM D4935-10 - Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar MaterialsASTM D4935-10 - Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar Materials
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ASTM D4935-10 - Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar Materials
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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: D4935 − 10
Standard Test Method for
Measuring the Electromagnetic Shielding Effectiveness of
1
Planar Materials
This standard is issued under the fixed designation D4935; 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.
1. Scope priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.1 Thistestmethodprovidesaprocedureformeasuringthe
electromagnetic (EM) shielding effectiveness (SE) of a planar
2. Referenced Documents
material for a plane, far-field EM wave. From the measured
4
2.1 ASTM Standards:
data, near-field SE values may be calculated for magnetic (H)
2,3
D1711Terminology Relating to Electrical Insulation
sources for electrically thin specimens. Electric (E) field SE
valuesmayalsobecalculatedfromthissamefar-fielddata,but
3. Terminology
their validity and applicability have not been established.
3.1 Definitions—For definitions of terms used in this test
1.2 The measurement method is valid over a frequency
method, refer to Terminology D1711.
rangeof30MHzto1.5GHz.Theselimitsarenotexact,butare
based on decreasing displacement current as a result of 3.2 Definitions of Terms Specific to This Standard:
decreased capacitive coupling at lower frequencies and on
3.2.1 dynamic range (DR), n—differencebetweenthemaxi-
overmoding (excitation of modes other than the transverse mum and minimum signals measurable by the system.
electromagnetic mode (TEM)) at higher frequencies for the
3.2.1.1 Discussion—Measurement of materials with good
size of specimen holder described in this test method. Any SE require extra care to avoid contamination of extremely low
number of discrete frequencies may be selected within this power or voltage values by unwanted signals from leakage
range. For electrically thin, isotropic materials with frequency paths.
independent electrical properties of conductivity, permittivity,
3.2.2 electrically thin, adj—thickness of the specimen is
and permeability, measurements may be needed at only a few 1
much smaller (< ⁄100) than the electrical wavelength within the
frequencies as the far-field SE values will be independent of
specimen.
frequency.Ifthematerialisnotelectricallythinorifanyofthe
3.2.3 far field, n—that region where vectors E and H are
parametersvarywithfrequency,measurementsshouldbemade
orthogonaltoeachotherandbotharenormaltothedirectionof
at many frequencies within the band of interest.
propagation of energy.
1.3 This test method is not applicable to cables or connec-
3.2.4 near field, n—that region where E and H are not
tors.
related by simple rules.
1.4 Units—The values stated in SI units are to be regarded
3.2.4.1 Discussion—The transition region between near
asstandard.Nootherunitsofmeasurementareincludedinthis
field and far field is not abrupt but is located at the distance
standard.
close to λ/2π from a dipole source, where λ is the free-space
wave length of the frequency of the source. This concept of
1.5 This standard does not purport to address all of the
regionsisfurtherblurredbyreradiatingasaresultofscattering
safety concerns, if any, associated with its use. It is the
by reflecting materials or objects that may be distant from the
responsibility of the user of this standard to establish appro-
source. The interior of metallic structures often contains a
mixture of near-field regions.
1
This test method is under the jurisdiction of ASTM Committee D09 on
3.2.5 shielding effectiveness (SE), n—ratio of power re-
Electrical and Electronic Insulating Materials and is the direct responsibility of
Subcommittee D09.12 on Electrical Tests.
ceived with and without a material present for the same
Current edition approved May 1, 2010. Published June 2010. Originally
incident power.
approved in 1989. Last previous edition approved in 1999 as D4935–99. DOI:
10.1520/D4935–10.
2
Wilson, P. F., and Ma, M. T., “A Study of Techniques for Measuring the
4
Electromagnetic Shielding Effectiveness of Materials,” NBS Technical Note 1095, For referenced ASTM standards, visit the ASTM website, www.astm.org, or
May 1986. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3
Adams, J. W., and Vanzura, E. J., “Shielding Effectiveness Measurements of Standards volume information, refer to the standard’s Document Summary page on
Plastics,” NBSIR 85-3035, January 1986. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D4935 − 10
3.2.5.1 Discussion—SE is usually expressed in decibels mid
...

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1.3 The values stated in either SI units of in inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore each system shall be used independently of the other. Combining values from the two systems is likely to result in non conformance with the standard. The equations shown here assume an e+jωt harmonic time convention.  
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5.1 These test methods are useful in research and quality control for evaluating insulating materials and systems since they provide for the measurement of charge transfer and energy loss due to partial discharges(4) (5) (6).  
5.2 Pulse measurements of partial discharges indicate the magnitude of individual discharges. However, if there are numerous discharges per cycle it is occasionally important to know their charge sum, since this sum is related to the total volume of internal gas spaces that are discharging, if it is assumed that the gas cavities are simple capacitances in series with the capacitances of the solid dielectrics (7) (8).  
5.3 Internal (cavity-type) discharges are mainly of the pulse (spark-type) with rapid rise times or the pseudoglow-type with long rise times, depending upon the discharge governing parameters existing within the cavity. If the rise times of the pseudoglow discharges are too long , they will evade detection by pulse detectors as covered in Test Method D1868. However, both the pseudoglow discharges irrespective of the length of their rise time as well as pulseless glow are readily measured either by Method A or B of Test Methods D3382.  
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SIGNIFICANCE AND USE
4.1 This test method applies to the measurement of SE of planar materials under normal incidence, far-field, plane-wave conditions (E and H tangential to the surface of the material).  
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1.2 The measurement method is valid over a frequency range of 30 MHz to 1.5 GHz. These limits are not exact, but are based on decreasing displacement current as a result of decreased capacitive coupling at lower frequencies and on overmoding (excitation of modes other than the transverse electromagnetic mode (TEM)) at higher frequencies for the size of specimen holder described in this test method. Select any number of discrete frequencies within this range. For electrically thin, isotropic materials with frequency independent electrical properties of conductivity, permittivity, and permeability, measurements will possibly be needed at only a few frequencies as the far-field SE values will be independent of frequency. If the material is not electrically thin or if any of the parameters vary with frequency, make measurements at several frequencies within the band of interest.  
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5.1 These test methods are useful in research and quality control for evaluating insulating materials and systems since they provide for the measurement of charge transfer and energy loss due to partial discharges(4) (5) (6).  
5.2 Pulse measurements of partial discharges indicate the magnitude of individual discharges. However, if there are numerous discharges per cycle it is occasionally important to know their charge sum, since this sum is related to the total volume of internal gas spaces that are discharging, if it is assumed that the gas cavities are simple capacitances in series with the capacitances of the solid dielectrics (7) (8).  
5.3 Internal (cavity-type) discharges are mainly of the pulse (spark-type) with rapid rise times or the pseudoglow-type with long rise times, depending upon the discharge governing parameters existing within the cavity. If the rise times of the pseudoglow discharges are too long , they will evade detection by pulse detectors as covered in Test Method D1868. However, both the pseudoglow discharges irrespective of the length of their rise time as well as pulseless glow are readily measured either by Method A or B of Test Methods D3382.  
5.4 Pseudoglow discharges have been observed to occur in air, particularly when a partially conducting surface is involved. It is possible that such partially conducting surfaces will develop with polymers that are exposed to partial discharges for sufficiently long periods to accumulate acidic degradation products. Also in some applications, like turbogenerators, where a low molecular weight gas such as hydrogen is used as a coolant, it is possible that pseudoglow discharges will develop.
SCOPE
1.1 These test methods cover two bridge techniques for measuring the energy and integrated charge of pulse and pseudoglow partial discharges:  
1.2 Test Method A makes use of capacitance and loss characteristics such as measured by the transformer ratio-arm bridge or the high-voltage Schering bridge (Test Methods D150). Test Method A has been found useful to obtain the integrated charge transfer and energy loss due to partial discharges in a dielectric from the measured increase in capacitance and tan δ with voltage. (See also IEEE 286 and IEEE 1434)  
1.3 Test Method B makes use of a somewhat different bridge circuit, identified as a charge-voltage-trace (parallelogram) technique, which indicates directly on an oscilloscope the integrated charge transfer and the magnitude of the energy loss due to partial discharges.  
1.4 Both test methods are intended to supplement the measurement and detection of pulse-type partial discharges as covered by Test Method D1868, by measuring the sum of both pulse and pseudoglow discharges per cycle in terms of their charge and energy.  
1.5 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. Specific precaution statements are given in Section 7.  
1.6 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.

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ASTM
ASTM D5388-21(Test Method)
Standard Test Method for Indirect Measurements of Discharge by Step-Backwater Method

SIGNIFICANCE AND USE
5.1 This test method is particularly useful for determining the discharge when it cannot be measured directly (such as during high flow conditions) by some type of current meter to obtain velocities and with sounding weights to determine the cross section (refer to Test Method D3858). This test method requires only one high-water elevation, unlike the slope-area test method that requires numerous high-water marks to define the fall in the reach. It can be used to determine a stage-discharge relation without data from several high-water events.  
5.1.1 The user is encouraged to verify the theoretical stage-discharge relation with direct current-meter measurements when possible.  
5.1.2 To develop a rating curve, plot stage versus discharge for several discharges and their computed stages on a rating curve together with direct current-meter measurements.
SCOPE
1.1 This test method covers the computation of discharge of water in open channels or streams using representative cross-sectional characteristics, the water-surface elevation of the upstream-most cross section, and coefficients of channel roughness as input to gradually-varied flow computations.2  
1.2 This test method produces an indirect measurement of the discharge for one flow event, usually a specific flood. The computed discharge may be used to define a point on the stage-discharge relation.  
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.4 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.  
1.5 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.

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ASTM
ASTM E1016-07(2020)(Guide)
Standard Guide for Literature Describing Properties of Electrostatic Electron Spectrometers

SIGNIFICANCE AND USE
5.1 The analyst may use this document to obtain information on the properties of electron spectrometers and instrumental aspects associated with quantitative surface analysis.
SCOPE
1.1 The purpose of this guide is to familiarize the analyst with some of the relevant literature describing the physical properties of modern electrostatic electron spectrometers.  
1.2 This guide is intended to apply to electron spectrometers generally used in Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS).  
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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.  
1.5 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.

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