ISO 3688:1999 パルプ—拡散青色反射率（ISO輝度）を測定するための実験用シートの準備 | ページ 2

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

International Standard ISO 3688 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps, Subcommittee SC 5, Test Methods and quality specifications for pulp.

This second edition cancels and replaces the first edition (ISO 3688:1977), of which it constitutes a technical revision.

Introduction

The reflectance factor depends on the manner of preparation of the laboratory sheets and also on the conditions of measurement, particularly the spectral and geometric characteristics of the instrument used.

1 Scope

This International Standard specifies two procedures for the preparation of laboratory sheets prior to measuring the diffuse blue reflectance factor (ISO brightness). One is the traditional procedure based on preparation of sheets in a Büchner funnel using a filter paper or a wire screen. In the other procedure, the sheets are prepared in a standard sheet former (conventional or Rapid Köthen).

Details of the subsequent measurement procedure are given in ISO 2470.

It is applicable to all wood pulps and to most other types of pulp. Pulps with very long fibres, such as those made from unshortened cotton, flax and similar materials, shall be reduced to a suitable fibre length before testing by this method.

This International Standard shall be used in conjunction with ISO 2469 and ISO 2470.

2 Normative references

The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.