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1、BRITISH STANDARD BS 7914:1998 Incorporating Amendment No. 1 Method of test for penetration of erythemally weighted solar ultraviolet radiation through clothing fabrics ICS 59.080.40 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:19:22 GMT+00:00 2006, Uncontr
2、olled Copy, (c) BSI BS 7914:1998 This British Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 January 1998 BSI 05-1999 The following BSI references relate to the w
3、ork on this standard: Committee reference TCI/66/7 Draft for comment 97/123067 DC ISBN 0 580 28970 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee TCI/66, Apparel, to Subcommittee TCI/66/7, Penetration of solar UVR thro
4、ugh clothing fabrics, upon which the following bodies were represented: British Clothing Industry Association British Leather Confederation British Textile Technology Group Consumer Policy Committee of BSI Department of Health Ministry of Defence National Physical Laboratory National Radiological Pr
5、otection Board Society of Dyers and Colourists Amendments issued since publication Amd. No.DateComments 10316January 1999 Indicated by a sideline in the margin Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:19:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS
6、 7914:1998 BSI 05-1999i Contents Page Committees responsibleInside front cover Forewordii 1 Scope1 2 References1 3 Principle1 4 Terms and definitions1 5 Apparatus2 6 Sample selection3 7 Specimen preparation3 8 Calibration3 9 Measurement4 10 Calculation of results4 11 Test report4 Annex A (normative)
7、 Calculation of UVR penetration5 Annex B (informative) Transmittance characteristics of typical UVR transmitting and UVR cut-off filters6 Figure B.1 Transmittance characteristic of UVR transmitting filter6 Figure B.2 Transmittance characteristic of UVR cut-off filter7 Table A.1 Spectral weighting fu
8、nction for erythema and spectral irradiance for a standard solar spectrum S as a function of wavelength 5 List of referencesInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:19:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7914:1998 ii BSI
9、05-1999 Foreword This British Standard has been prepared by Subcommittee TCI/66/7 to provide a method for the assessment of the penetration of solar ultraviolet radiation through clothing fabrics. It is intended that subsequent standards dealing with clothing product labelling will refer to the meth
10、od contained in this British Standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Su
11、mmary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside
12、front cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:19:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7914:1998 BSI 05-19991 1 Scope This British Standard describes a method of test to establish the penetration of solar ultraviolet radiation (UVR),
13、 weighted spectrally for erythema (sunburn), through clothing fabrics (i.e. fabrics in close proximity to the skin surface) in a relaxed conditioned state. This standard does not address related issues such as the design of fabrics and textile products for solar UVR protection, the classification of
14、 such products for their solar UVR protecting capabilities or the protection afforded by sunscreens, sunglasses or other non-fabric agents. It does not address the penetration of solar UVR through the brims of hats, shadecloth and umbrella fabric. NOTEShade structures which are not in close proximit
15、y to skin surfaces may provide in practice a lesser degree of solar UVR protection to the skin than indicated by laboratory testing, due to UVR back scattering. 2 References 2.1 Normative references This British Standard incorporates, by dated or undated reference, provisions from other publications
16、. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back cover. For dated references, only the edition cited applies; any subsequent amendments to or revisions of the publications apply to this British Standard only when inc
17、orporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 2.2 Informative references This British Standard refers to other publications that provide information or guidance. Editions of these public
18、ations current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest editions. 3 Principle The penetration of solar UVR through a fabric specimen is determined as the ratio of the erythemally weighted solar UVR irradiance measured by a
19、detector with a test clothing fabric specimen in place to that measured with no fabric present. NOTEThe mathematical definition of the penetration of solar UVR through a fabric specimen used in this British Standard is given in Annex A. 4 Terms and definitions For the purposes of this British Standa
20、rd, the following definitions apply. 4.1 angular divergence angle between the axis (normal to the specimen) and any ray in the irradiating or collecting beam 4.2 back scattering deflection of optical radiation by scattering through angles greater than 90 with reference to the original direction of t
21、ravel 4.3 conditioned fabric fabric in equilibrium with the standard temperate atmosphere for testing described in BS EN 20139 NOTEFor the purposes of this British Standard, fabric samples having been stored in this atmosphere for 16 h are considered to be in equilibrium with it. 4.4 erythema redden
22、ing of the skin caused by various physical or chemical agents NOTEThis British Standard considers the photochemical effects of UVR. 4.5 erythemally effective radiometric or spectroradiometric quantity which has been weighted for the effects of erythema 4.6 fabric manufactured assembly of fibres and/
23、or yarns that has a substantial surface area in relation to its thickness and sufficient mechanical strength to give the assembly inherent cohesion 4.7 fluorescence absorption of radiation of a particular wavelength and its re-emission within a very short time as optical radiation of greater wavelen
24、gth NOTEIn order to accurately determine the UVR transmittance of a sample, it is necessary to ensure that any optical radiation, outside the UVR region, generated by fluorescence by the sample, the filter or some other source, does not reach the detector system. 4.8 integrating sphere hollow sphere
25、 whose internal surface is a non-selective diffuse reflector (lambertian) Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 13:19:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7914:1998 2 BSI 05-1999 4.9 irradiance radiant flux on an infinitesimal surface eleme
26、nt containing the point under consideration divided by the area of that surface element 4.10 reflectance ratio of radiant flux reflected at a given wavelength to that incident at the same wavelength for a given set of conditions 4.11 sample whole amount of a clothing fabric submitted for test 4.12 s
27、cattering process by which the spatial distribution of a beam of optical radiation is changed when it is deviated in many directions by a surface or by a medium, without change of frequency of its monochromatic components 4.13 shadecloth fabric that is specifically used to provide shade from sunligh
28、t other than for apparel purposes 4.14 solar UVR UVR from the sun NOTEThe wavelength range for solar UVR at the Earths surface is defined as 290 nm to 400 nm, and a standard solar spectrum is given in Table A.1. 4.15 specimen part or region of a sample submitted for testing 4.16 spectral bandwidth w
29、idth in nanometres at half height of the peak intensity of optical radiation emerging from a monochromator 4.17 spectral transmittance ratio of the radiant flux transmitted at a given wavelength to the radiant flux incident at that wavelength 4.18 UVR transmitting filter filter which transmits signi
30、ficantly only at wavelengths less than approximately 400 nm and which does not fluoresce 5 Apparatus 5.1 Spectrophotometer/spectroradiometer,1) fitted with a UVR source (5.2), an integrating sphere (5.3), a filter (5.4), if appropriate, and a detector sensitive throughout the wavelength range 290 nm
31、 to 400 nm for a measurement of the total transmittance (i.e. both the direct and diffuse components). The overall system without a specimen shall have a signal-to-noise ratio greater than 50 : 1 throughout the wavelength range 290 nm to 400 nm. The apparatus shall either irradiate the fabric with p
32、arallel radiation and collect all the radiation (direct and diffuse) transmitted using an integrating sphere, or irradiate the fabric hemispherically and collect a parallel beam of transmitted radiation. In addition, the fabric may be irradiated with monochromatic radiation (type 1) or by polychroma
33、tic radiation and collected monochromatically (type 2). 5.2 UVR source, providing UVR continuum throughout the wavelength range 290 nm to 400 nm. Suitable sources include a xenon arc lamp, a high-intensity tungsten halogen lamp and a deuterium lamp. The angle of irradiation or collection of the UVR
34、beam shall be within 5 of the beam axis. The spectral bandwidth in the wavelength region 290 nm to 400 nm shall be 5 nm or less. The beam diameter shall be a minimum of 3 mm and at least three times the repeat fabric construction (i.e. weave or knit structure). The beam shall be normal to the fabric
35、 to less than 3. 5.3 Integrating sphere, having total openings representing no more than 10 % of the internal spherical surface area and having an internal surface lined with a highly reflective matt surface (e.g. barium sulfate paint). This internal surface shall be recoated when the reflectance be
36、comes less than 75 % at any wavelength in the range 290 nm to 400 nm. The sphere shall be fitted with baffles to shield the detector (type 1) or source (type 2) from: a) the specimen port; and b) the sphere wall where the incident flux is measured. NOTEThe signal-to-noise ratio should be monitored a
37、s it may provide an indication of integrating sphere efficiency (wall reflectance). 1) For details of suppliers of spectrophotometers and spectroradiometers suitable for this application, contact BSI Information Centre, 389 Chiswick High Road, London W4 4AL. Licensed Copy: London South Bank Universi
38、ty, London South Bank University, Fri Dec 08 13:19:22 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7914:1998 BSI 05-19993 5.4 UVR transmitting filter, placed after the sample to prevent fluorescence in the visible region from the fabric being included in the measurements and required for an instrum
39、ent which monochromates before the specimen (type 1); if the instrument monochromates after the specimen (type 2), a UVR transmitting filter is not required. The UVR transmitting filter shall be in place for all measurements. The filter shall be placed in front of the detector, or, when this is not
40、practical, it shall be placed at the specimen port between the specimen and the sphere, but corrections shall then be determined and applied to the results (see 5.6). NOTEThe transmittance characteristic of a filter suitable for this purpose is given in Annex B.2) 5.5 Cut-off filter, having zero tra
41、nsmittance between 200 nm and 400 nm and high transmittance between 420 nm and 800 nm, non-fluorescing, and recommended for double beam type 1 instruments to ensure that the fluorescence properties and back scatter have been adequately minimized. NOTEThe transmittance characteristic of a filter suit
42、able for this purpose is given in Annex B.2) 5.6 Specimen holders, to hold specimens in a flat, tensionless state and of a size larger than the entrance port of the integrating sphere, and ideally in the plane of the integrating sphere port. NOTEDepending on the instrument design and the scattering
43、characteristics of the specimen, failure to position the specimen directly in the plane of the sphere port can lead to a 3 % to 5 % specimen recess error in transmittance per millimetre of gap. A specimen recess error will reduce the transmittance measured by that instrument. The specimen recess err
44、or induced by moving a specimen away from the sphere wall can be assessed by using a transfer standard (calibrated fabric specimen) by the following method. a) Measure the calibrated specimen at the specimen position of the instrument. b) Take the ratio of the measured to calibrated values and mean
45、over the wavelength range 290 nm to 400 nm. c) This ratio is defined as the specimen recess error and should be used to scale all future specimen measurements by dividing the measured transmittance by this ratio. 6 Sample selection Include any open structures (holes) in fabric samples in the test sp
46、ecimens. NOTE 1Open structures are included because it is the highest level of penetration through the fabric which is to be reported. Use a sample size of at least 0.5 m in length (or a full pattern and/or colour repeat, whichever is greater). For a multicoloured fabric, test each colour separately
47、, and for a fabric varying in composition and/or construction, test each area of different fabric separately. NOTE 2Each colour and/or composition and construction is tested separately because the solar UVR penetration is likely to be different for each of them. 7 Specimen preparation 7.1 Selection
48、Prepare at least four specimens for each sample submitted for test. For non-uniform samples, prepare at least two specimens for each colour variation and/or textural change across the sample, each subject to the following criteria. a) No two specimens shall incorporate the same yarn/fibres. b) Speci
49、mens shall not be taken from within 10 % of the overall fabric width from the edge. Variations occurring over a distance of less than 3 mm shall be averaged over a specimen diameter of at least 3 mm. NOTEThe smallest practicable distance over which to sample variations in colour and/or texture is considered to be 3 mm diameter. 7.2 Conditioning Condition all specimens at (20 2) C and relative humidity of (65 2) % in accordance with BS EN 20139 for at least 16 h. If the testing instrument is not sited in this standard atmosphere, hermetically seal the condition
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