ISO 9050:2003 pdf download
ISO 9050:2003 pdf download.Glass in building一Determination of
light transmittance, solar direct transmittance, total solar energy transmittance, ultraviolet transmittance and related glazing factors.
If the value of a given characteristic is required for different glass thicknesses (in the case of uncoated glass) or for the same coating applied to different glass substrates, it may be obtained by calculation (see Annex A).
If nothing else is stated, the published characteristic parameters shall be determined using the standard conditions given in 3.3 to 3.7. Other optional conditions given in Clause 4 shall be stated.
When calculating the characteristic parameters of multiple glazing, the spectral data of each glass component instead of integrated data shall be used.
3.2 Performance of optical measurements
Optical measurements in transmission and reflection require special care and much experimental experience to achieve an accuracy in transmittance and reflectance of about ± 0,01.
Commercial spectrophotometers (with or without integrating spheres) are affected by various sources of inaccuracy when used for reflectance and transmittance measurements on flat glass for building.
The wavelength calibration and the photometric linearity of commercial spectrophotometers shall be checked periodically using reference materials obtained from metrological laboratories.
The wavelength calibration shall be performed by measuring glass plates or solutions which feature relatively sharp absorption bands at specified wavelengths; the photometric linearity shall be checked using grey filters with a certified transmittance.
For reflectance measurements, reference materials having a reflection behaviour (i.e. reflectance level and ratio of diffuse and direct reflectance) similar to the unknown sample shall be selected.
Thick samples (e.g. laminated glass or insulating units) can modify the optical path of the instrument’s beam as compared to the path in air and therefore the sample beam hits an area of the detector having a different responsivity.
A similar source of inaccuracy occurs in case of samples with significant wedge angles which deflect the transmitted (and reflected) beams. It is recommended to check the reproducibility by repeating the measurement after rotating the sample.
3.5.6.1 They represent well-defined average boundary conditions. In this way basic information on the performance of glazing is obtained and an appropriate comparison of different products in technical information can be achieved.
To meet special local and product requirements, the characteristics of this International Standard may also be determined for the following different boundary conditions:
the standardized values for the heat transfer coefficients to the outside and the inside (see 3.5.6.1) may be replaced by other values;
— for the determination of the thermal conductance(s) A (see 3.5.6.3 and 3.5.6.4), the standardized values (i.e. a mean sample temperature of 10 °C and a temperature difference AT= 15 °C across the sample) may be substituted by other values.
If the specified standard conditions prescribed in 3.5.6.1 are varied as allowed above, the test report shall mention what standard conditions have been changed and shall detail the variations.
5 Test report
The test report shall state the following:
— the results for the required characteristics;
— the number and thickness of panes in the glazing;
the type and position of panes (for the case of multiple glazing), designated as outer pane, second pane, etc.;
— the position of coating(s) (for the case of coated glass) designating the faces of the panes as 1, 2, 3, etc., starting from the outer surface of the outer pane;
— the type of instrument used for the optical measurements (specifying, if used, the reflectance accessory or integrating sphere and reference materials for reflectance);
— specification of boundary conditions if different from standardized values (see Clause 4).
The general colour rendering index Ra shall be given to two significant numbers; all other characteristics to two decimal places.
