BS EN 17317-2020 Resilient, textile, laminate and modular mechanical locked floor coverings一Light reflectance value (LRV) of a flooring surface.
Sphere-type spectropliotometer. capable of measuflng 1KV to a prclslon compatible wfth the reproducibility of 1 unit ilE C1 Lab’.
The instrument shall have a spectral range capable of measunng the LRV of a specimen at 16 wavelength paints spaced at 20 inn wavelength LntrfValS from 404) nm across the visible spectrum
The rnstrument shall be capable of measuring a 10° visual field (Vu or the 10° standard coiorlmetric observerj.
The instrument shall he designed such that a correctly positioned specimen is Irradiated uniformly from MI directions within the hemisphere bounded by its plane.
The instrument aperture shall be delimited by the area over which the receiver senses flux rather than the area illuminated. Radiation reflected at the sampling aperture shall he evaluated unitQrmly at all directions within 5o1 the axis of the collection beam.
The axis of the reflected beam shall be 80 otT the normal of the centre at the specimen plane in which the specimen is placed dunng measurements. The reduction in sphere efficiency due to specimen abwrption shall be corrected to produce a linear output
Where a single beam integrating sphere is used, the treatment of the outputs needs to indude a
correction for the reduction In sphere efficiency caused by specimen absorption. Without such a
correction the Instrument wdl give a nonlinear output.
Standard illumun.unt. CIE 065. This is generally representative of a phase of daylight with a correlated colour temperature of approximately 6 500 K.
Measurement area, of at least 7mm diameter compatible with that provided by commercially available spectrophotorneters.
7 Test specimens
Three specimens shall he selected as being representative of the surface for the test. Where there is variability in the colour of the three specimens, then nine specimens shall be selected, see below note to decide on.
NOTE Variability in the colour of the three specimens will be deemed to have occurred where the difference between the highest and lowest LRV is a 4
7.2 PreparatIons of test specimens
The surface of the specimens shall be dean and representative 01 the surface of the material There shall be no pressure marks on. or foreign matter attached to. the surface of the specimens to be testeil
Cut pile carpets (textile floor coverings) shall be brushed with a clothing brush In the direction of the natural pile by before measurement.
Where there Is concern with regard to the stability of the colour and appearance of a specimen over the period of the test, the specimen shall not be measured.
Specimens shall be large enough to extend beyond the measurement area of the instrument.BS EN 17317 pdf download.