BS EN 62805-1-2017 pdf free download.Method for measuring photovoltaic (PV) glass Part 1: Measurement of total haze and spectral distribution of haze
This part of IEC 62805 specifies a method for measurement and calculation of the total haze and the spectral distribution of haze of glass used in photovoltaic (PV) modules.
This document is applicable to glass used in PV modules, including transparent conductive oxide coated (TCO) glass and other kinds of glass used in PV modules.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60904-3:201 6, Photovoltaic devices – Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data
IEC TS 61 836, Solar photovoltaic energy systems – Terms, definitions and symbols
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC TS 61 836 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 PV glass
glass used in PV modules, including cover or front glass, back glass and substrate glass
3.2 transparent conductive oxide coated (TCO) glass
flat glass coated with a transparent conductive oxide film that is used as a conductive layer Note 1 to entry: This note applies to the French language only.
3.3 total haze
ratio of the scattered photon flux to the total photon flux transmitted through the PV glass in the wavelength range 280 nm to 1 250 nm, when the direction of the scattered light deviates more than 2,5° from the direction of the incident beam
3.4 spectral distribution of haze
a plot or table of haze versus wavelength
Note 1 to entry: The haze of PV glass is measured at a specific set of wavelengths (λ), for this standard in the wavelength range 280 nm to 1 250 nm.
3.5 single beam spectrometer
type of spectrometer, where all the light coming from a radiation source passes through the sample under test so that to measure the intensity of the incident light the sample must be removed and all the light can be measured directly
3.6
double beam spectrometer
more advanced type of spectrometer, where the light source is split into two separate beams before it reaches the sample under test, so that one beam passes through the sample and the second one is used for reference
Note 1 to entry: This has the advantage that the reference reading and sample reading are take place at the same time.
4 Apparatus
4.1 General
Both double-beam instruments and single-beam instruments may be used for the haze measurements. The apparatus shall consist of the following elements:
• a stabilized light source. The wavelength range of the light source shall include 280 nm to 1 250 nm. For the single-beam instrument, the voltage of the light source shall be stabilized within ±1 %;
• for the double-beam instrument, an optical system that forms two parallel beams of monochromatic radiation of the same wavelength λ and approximately equal radiant flux from the output of the monochromator;
• an integrating sphere fitted with ports and a photodetector. A diameter of the integrating sphere of not less than 1 50 mm is recommended. (If an integrating sphere with diameter less than 1 50 mm is used, the total area of the sphere ports shall not exceed 4 % of the internal surface area of the integrating sphere. Unused ports which are closed and covered with the same coating as the rest of the inner walls of the sphere do not have to be taken into account);
• the schematic arrangements of the double-beam integrating sphere and the single-beam integrating sphere used for measurement are shown in Figure 1 a) and Figure 1 b) respectively. The photodetector is mounted in the photodetector port in a manner that allows it to view with equal efficiency all parts of the sphere. Ingress of stray external light into the integrating sphere shall be prevented.BS EN 62805-1 pdf download