BS EN 17317:2020 pdf free.Resilient, textile, laminate and modular mechanical locked floor coverings - Light reflectance value (LRV) of a flooring surface. BS EN 17317 The instrument shall have a spectral range capable of measuring the LRV of a specimen at 16 wavelength points spaced at 20 nm wavelength intervals from 400 nm across the visible spectrum.The instrument shall be...