This document describes the general procedure for measuring the diffuse radiance factor of all types of pulp, paper and board. More particularly, it specifies in detail the procedures to be used for calibrating the equipment, and in Annex？A, the characteristics of the equipment to be used for such measurements.

This document can be used to measure the diffuse radiance factors and related properties of materials containing fluorescent whitening agents, provided that the UV-content of the instrument illumination has been adjusted to give the same level of fluorescence as a fluorescent reference standard for a selected CIE illuminant, according to the International Standard describing the measurement of the property in question.

Annex？C describes the preparation of fluorescent reference standards.