BS/EN 62805-1-2017 pdf download.Method for measuring photovoltaic (PV) glass
Part 1: Measurement of total haze and spectral distribution of haze.
Note 1 to entry: The haze of PV glass is measured at a specific set of wavelengths (A). 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
doub’e 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 hme,
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 A 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 150 mm is recommended. (If an integrating sphere with diameter less than 150 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 la) and Figure ib) 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.
Figure 1 and the text describe the configuration with the wavelength determining element (e.g. a monochromator) in front of the integrating sphere and a non-selective detector at the output of the integrating sphere. In practice, configurations using white light at the input of the integrating sphere and a wavelength selecting element with detector at the output of the integrating sphere may be used as well. The procedures described In this standard apply to both configurations.
4.2 Performance of test instrument
The wavelength range of the instrument shall include 280 nm to 1 250 nm.
The spectral bandwidth shall be adjusted to less than the required measuring wavelength interval.
The wavelength accuracy of the instrument shall be within ±0,5 nm from 280 nm to 900 nm, and ±1 nm from 900 nm to 1 250 nm.
In the wavelength range of 280 nm to 1 250 nm. the accuracy of transmittance measurement shall be within ±0.3 %. and the repeatability of transmittance measurement shall be within
±0,1 %.
Geometric condition for illumination and detection: The angle between normal of the sample and optical axis of the illuminating beam for the measurement should be 10. The angle that any ray of the illuminating beam may make with the beam axis should be 3.
NOTE The accuracy oniy relers to the instrument Itself, and it does not include the uncertainty of the standard white reference plate used.
5 Test specimens
Test specimens shall meet the following requirements:BS/EN 62805-1-2017 pdf download.
BS/EN 62805-1-2017 pdf download
PS:Thank you for your support!
