1、July 2011 Translation by DIN-Sprachendienst.English price group 9No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 91
2、.100.50!$s5“1805818www.din.deDDIN EN 15976Flexible sheets for waterproofing Determination of emissivityEnglish translation of DIN EN 15976:2011-07Abdichtungsbahnen Bestimmung des EmissionsgradesEnglische bersetzung von DIN EN 15976:2011-07Feuilles souples dtanchit Dtermination de lmissivitTraduction
3、 anglaise de DIN EN 15976:2011-07www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1307.11 DIN EN 15976:2011-07 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 25
4、4 “Flexible sheets for waterproofing” (Secretariat: BSI, United Kingdom). The responsible German body involved in its preparation was the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Working Committee NA 005-02-91 AA Flexible Bahnen unter Dachdeckungen (SpA zu CEN/T
5、C 254/WG 9). 2 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15976 April 2011 ICS 91.100.50 English Version Flexible sheets for waterproofing - Determination of emissivity Feuilles souples dtanchit - Dtermination de lmissivit Abdichtungsbahnen - Bestimmung des Emissionsgrades This European St
6、andard was approved by CEN on 17 March 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning
7、 such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its
8、 own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, I
9、taly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1
10、000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15976:2011: EEN 15976:2011 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Symbols 45 Principle of low emitting surfaces .
11、56 Hemispherical blackbody radiator .66.1 Principle of hemispherical blackbody radiator .66.2 Description of hemispherical blackbody radiator and of the specimen holder 76.3 Handling procedure of calibration standards .86.4 Calculation of the emissivity 96.5 Measurement range of hemispherical blackb
12、ody radiator 97 Sampling and preparation of the test specimens 97.1 Sampling .97.2 Dimensions and numbers of specimens .97.3 Preparation of specimens before testing 98 Procedure for measurement of specimens .99 Expression of the results . 1010 Emissivity after conditioning . 1010.1 Specialities of a
13、pplication related aging 1010.2 Conditioning procedure . 10Bibliography . 11DIN EN 15976:2011-07 EN 15976:2011 (E) 3 Foreword This document (EN 15976:2011) has been prepared by Technical Committee CEN/TC 254 “Flexible sheets for waterproofing”, the secretariat of which is held by BSI. This European
14、Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 2011. Attention is drawn to the possibility that some of the elements
15、 of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this Europe
16、an Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the
17、 United Kingdom. DIN EN 15976:2011-07 EN 15976:2011 (E) 4 1 Scope This European Standard specifies the method to determine the emissivity of plastic, rubber and bitumen vapour control layers, underlays for walls and underlays for discontinuous roofing. It also defines a conditioning procedure for th
18、ese product families in order to quantify the sensitivity of emissivity to humidity and temperature. 2 Normative references The following referenced documents are indispensable for the application of this European Standard. For dated references, only the edition cited applies. For undated references
19、, the latest edition of the referenced document (including any amendments) applies. EN 13416, Flexible sheets for waterproofing Bitumen, plastic and rubber sheets for roof waterproofing Rules for sampling 3 Terms and definitions For the purposes of this document, the following terms and definitions
20、apply 3.1 emissivity emissivity of a material (usually written ) is the ratio (proportion) of the energy radiated by a surface relative to the energy radiated by a blackbody at the same temperature. It is a measure of a materials ability to radiate heat 3.2 blackbody blackbody is a theoretical objec
21、t that absorbs all electromagnetic radiation that falls on it at all wavelengths. No electromagnetic radiation passes through it and none is reflected NOTE A blackbody is also a perfect emitter with a normal and corrected emissivity of 1. 3.3 TIR Thermal Infrared Radiation principle 4 Symbols For th
22、e purposes of this document, the following symbols apply c specific heat capacity is the measure of the heat energy required to increase the temperature of a unit quantity of a substance by a certain temperature interval. the wavelength is the distance between repeating units of a propagation wave o
23、f a given frequency. NOTE In this document it is understood the wave length is limited to the infrared light spectrum. DIN EN 15976:2011-07 EN 15976:2011 (E) 5 (alpha) represents the absorption coefficient of a surface and is the ratio of the radiant energy absorbed by that surface relative to that
24、of a blackbody at the same temperature. (epsilon) emissivity (see above definition of emissivity) (0 1). (rho) reflectivity coefficient is the proportion of the incident electromagnetic radiation reflected from a surface or an optical element. (tau) transmission coefficient is the proportion of inci
25、dent electromagnetic radiation (light) passes through a surface or an optical element. Lemissivity for the low emissive calibration standard. H emissivity for the high emissive calibration standard.U sensor signal of the specimen in Volt. UHsensor signal of the high emissive calibration standard in
26、Volt. ULsensor signal of the low emissive calibration standard in Volt. 5 Principle of low emitting surfaces Flexible sheets for waterproofing with a low emitting surface are commonly referred to as radiant or reflective barriers. The principle of a radiant barrier is based on its ability to reflect
27、 radiant heat instead of absorbing it. Radiation (radiant heat) is the transmission of electromagnetic rays through space and in this context “radiation” refers only to the energy of infrared rays. At any temperature, all objects radiate infrared rays, which travel in all directions until they are r
28、eflected or absorbed by another object. The heating of objects excites the molecular surface structure, resulting in an emission of infrared radiation from the surface. The radiative flux through a body will satisfy the conservation-of-energy equation: + + = 1 Radiant barriers are typically rather o
29、paque to infrared radiation, so in a simplified consideration the transmission is negligible: = 0 + = 1 = 1 - DIN EN 15976:2011-07 EN 15976:2011 (E) 6 Key 1 Incident energy 3 Absorbed energy 2 Reflected energy 4 Emitted energy Figure 1 Energy diagram The amount of emitted radiation is a function of
30、the emissivity factor () of the source surface. At the same nominal wave length the absorption factor () equals the emissivity factor (): = 6 Hemispherical blackbody radiator 6.1 Principle of hemispherical blackbody radiator The hemispherical radiator (half sphere) in the form of a blackbody uses th
31、e thermal infrared radiation principle (TIR-principle). The temperature of the blackbody is set and controlled at 100 (+/- 0,5 C). The hemispherical shape of the radiator is necessary in order to achieve a complete and homogenous illumination of the measuring surface allowing even the emissivity of
32、rough and structured surfaces to be measured correctly. Part of the energy reflected and emitted by the sample passes through a small opening in the hemispherical radiator and is focussed onto an infrared sensor by an infrared lens. The infrared sensor changes the incident thermal radiation into a v
33、oltage signal in a broad band and linear manner (the voltage signal is proportional to the reflected thermal energy). At any given temperature of a blackbody, the spectral distribution of the thermal radiation is given by Plancks law. The radiators temperature has been chosen to be 100 ( 0,5 C) so t
34、hat the corresponding spectrum DIN EN 15976:2011-07 EN 15976:2011 (E) 7 has its peak at a wavelength () of ca 8 m and more than 97 % of the radiant energy is in the wavelength range from (2,5 to 40) m. Key 1 Thermopile Ir Sensor 2 Ir lens 3 Sample Figure 2 Hemispherical blackbody radiator 6.2 Descri
35、ption of hemispherical blackbody radiator and of the specimen holder In order to reduce the hemispherical blackbody radiator (in the following also written as apparatus) related errors to a minimum the half sphere should have a diameter of not smaller than 70 mm. Also the distance of the surface to
36、measure to the apparatus shall be approximately 2 mm. The axis of the infrared sensor and infrared lens assembly shall point at the centre of the specimen and shall be between 70 and 80 to the specimen surface. An adequate electronic method to evaluate the measuring signals should be applied. In ord
37、er to avoid the heat up of the specimen the measuring time should be limited to 3 s maximum. DIN EN 15976:2011-07 EN 15976:2011 (E) 8 The specimen holder should have a solid flat front surface with a minimum of 140 mm by 140 mm. The fixation of the specimen onto the specimen holder should be adapted
38、 to the type of material to test. The specimen must be flat and wrinkle-free over the whole surface. Thin materials may be wrapped around the left and the right edges of the specimen holder and then fixed on both sides by magnetic strips. For thick and stiff materials, fixing should be adapted on ca
39、se by case basis (clamps, hooks, etc.). The specimen must be maintained parallel to the apparatus during measurement. The distance of 2 mm between specimen and apparatus should be pre-defined by spacers, which should also prevent any rocking of the specimen. Dimensions in milimetres Figure 3 Hemisph
40、erical blackbody radiator and specimen 6.3 Handling procedure of calibration standards Typical calibration standards for low emitting surface should be 0,01 0,94. Calibration standards must be certified by the manufacturer of the apparatus or by an independent Institute, accompanied by a certificate
41、 showing the measured emissivity. The calibration standards must be recertified (or replaced by new certified standards) at least every two years. The calibration standards must be stored in a dark, clean, dust-free and dry environment. If the low emissivity calibration standard shows up spots with
42、different brightness, scratches or other visual defects caused by handling, it shall be replaced. DIN EN 15976:2011-07 EN 15976:2011 (E) 9 6.4 Calculation of the emissivity Determination of the emissivity () results from comparing the measuring result of the specimen with the two calibration standar
43、ds. With the sensor signals (U, UHand UL) and the known emissivity of calibration standards (L and H), the of the specimen is calculated by: 6.5 Measurement range of hemispherical blackbody radiator The measurement range of the apparatus is limited to values between those of the two calibration stan
44、dards used thus from emissivity range of 0,02 0,94. 7 Sampling and preparation of the test specimens 7.1 Sampling A sheet sample of an undamaged roll shall be selected in accordance with EN 13416. 7.2 Dimensions and numbers of specimens A minimum of five specimens should be taken with a regular spac
45、ing. The specimen size should be adapted to the size of the specimen holder and to the fixation system of the specimen holder (see 6.2). 7.3 Preparation of specimens before testing The specimens should be kept for a minimum of 2 h at a temperature of 23 2 C and relative humidity of 50 20 %. Special
46、precaution should be taken to ensure that the calibration standards, the specimens and the apparatus are equilibrated in the same standard climatic conditions. Air currents and draughts in the measuring area must be avoided. 8 Procedure for measurement of specimens The apparatus should be switched o
47、n at least 2 h before calibration and beginning measurements. The apparatus should be installed in a fixed position and must not be moved during measurement. The specimen is brought up to the apparatus in a vertical orientation, pressed firmly against the spacers around the measuring window of the a
48、pparatus and the apparatus is activated to begin measurement. In order to avoid that the specimen temperature changes during the measurement, the residence time of the specimen in the measuring position must be reduced to a minimum. Between specimen positioning and start of measurement, not more tha
49、n 1 s shall pass. If this speed of measurement is not achieved, if the measurement is otherwise interrupted or if the measurement on a specimen is to be repeated, the specimen should be withdrawn from the apparatus for the time it needs to cool down to laboratory temperature. The higher the emissivity and/or the lower the specific heat capacity ( c ) of the material, the longer the specimen will need to cool down to laboratory
