BS ISO 2470-1:2016 pdf free

BS ISO 2470-1:2016 pdf free.Paper, board and pulps – Measurement of diffuse blue reflectance factor
intrinsic diffuse radiance (reflectance) factor measured with a reflectometer having the characteristics described in ISO 2469, equipped with a filter or corresponding function having an effective wavelength of 457 nm and a half bandwidth of 44 nm, and adjusted so that the UV content of the irradiation incident upon the test piece corresponds to that of the CIE illuminant C
Note 1 to entry: The filter function is described more fully by the weighting function factors given in Annex A and Table A.1.
A test piece is illuminated diffusely in a standard instrument and the light reflected normal to the surface is either allowed to pass through a defined optical filter and then measured by a photodetector or measured by an array of photosensitive diodes, where each diode responds to a different effective wavelength. The brightness is then determined directly from the output from the photodetector or by calculation from the photosensitive diode outputs using the appropriate weighting function.
Calibrate the instrument according to the instrument maker’s instructions, using a non-fluorescent international reference standard of level 3 (IR3) (5.2.2) or a working standard (5.3.1) calibrated in relation to an IR3. If the instrument is of the abridged spectrophotometer type, adjust the setting of the UV-adjustment filter or of a system having a corresponding function (see 5.1.3) using the fluorescent (5.2.3) and non-fluorescent (5.2.2) international reference standards of level 3 (IR3s), in accordance with the instrument maker’s instructions.
Remove the protective sheets from the test piece pad. Without touching the test area, use the procedure appropriate to the instrument to measure the ISO brightness of the top side of the test piece pad. Read and record the value to the nearest 0,05 % or better of the diffuse reflectance factor.
Move the measured test piece to the bottom of the pad and determine the ISO brightness for the next test piece and similarly for the following test pieces until a total of not less than 10 test pieces has been measured.BS ISO 2470-1 pdf free.