GB/T 462-2023Paper, board and pulps - Determination of moisture content of analytical sample (English PDF)

3.2 and 3.5 of this Edition);

c) Change the definition of constant mass (see 3.3 of this Edition; 3.2 of the 2008 Edition);

d) Change the requirements for the graduation value of the balance (see 5.1 of this Edition;

5.1 of the 2008 Edition);

e) Change the content and expression of sampling (see Clause 7 of this Edition; Clause 7 of

the 2008 Edition);

f) Add preparation of specimen (see Clause 8 of this Edition);

g) Change the test procedures (see 9.1.1 of this Edition; 8.2 of the 2008 Edition);

h) Add the test procedures for suspensions of cellulose nanomaterials (see 9.2 of this

Edition);

i) Add the calculation of dry matter content (see 10.2 of this Edition);

j) Change the test report (see Clause 11 of this Edition; Clause 10 of the 2008 Edition).

This Document modified and adopted ISO 287.2017 Paper and Board - Determination of

Moisture Content of a Lot - Oven-Drying Method; ISO 638-1.2022 Paper, Board, Pulps and

Cellulosic Nanomaterials - Determination of Dry Matter Content by Oven-Drying Method -

Part 1.Materials in Solid Form; ISO 638-2.2022 Paper, Board, Pulps and Cellulosic

Nanomaterials - Determination of Dry Matter Content by Oven-Drying Method - Part 2.

Suspensions of Cellulosic Nanomaterials.

Compared with ISO 287.2017, ISO 638-1.2022 and ISO 638-2.2022, this Document had more

structural adjustments. The comparison list of change in structure numbers of the 4 documents

can refer to Appendix A.

The technical differences and causes between this Document and ISO 287.2017, ISO 638-

1.2022 and ISO 638-2.2022 are as follows.

a) Change the Scope (see Clause 1 of this Document) to comply with the drafting rules of

China's standardization documents;

b) Change the definition of constant mass (see 3.3 of this Document) to correspond to the

content in the test procedures;

c) Replace ISO 186 (see 7.1 of this Document) by the normative reference GB/T 450 to

adapt to China's technical conditions;

d) Replace ISO 7213 (see 7.1 of this Document) by the normative reference GB/T 740 to

adapt to China's technical conditions;

e) Change the preparation method of specimen (see Clause 8 of this Document); and

simplify the content of Clause 8 of ISO 287.2017 to make the standard content easier to

operate and adapt to China's national conditions;

f) Delete the Clause 10 of ISO 638-1.2022 and ISO 638-2.2022.

This Document made the following editorial modifications.

--- Delete Appendix A (Informative) of ISO 287.2017; and Appendixes A (Informative) and

B (Informative) of ISO 638-1.2022 and ISO 638-2.2022.

Please note some contents of this Document may involve patents. The issuing agency of this

Document shall not assume the responsibility to identify these patents.

This Document was proposed by China National Light Industry Council.

This Document shall be under the jurisdiction of National Technical Committee on

Papermaking Industry of Standardization Administration of China (SAC/TC 141).

Drafting organizations of this Document. Zhejiang Guoli Packaging Co., Ltd.; Kingdecor

(Zhejiang) Co., Ltd.; China National Pulp and Paper Research Institute Co., Ltd.; Sinolight

Paper Inspection & Certification Co., Ltd.; Sinolight (Jinjiang) Hygiene Products Research Co.,

Ltd.; Idifubei (Chongqing) Technology Co., Ltd.; Shandong Bohui Paper Industrial Co., Ltd.;

Zhejiang Zhongxin Environmental Protection Technology Group Co., Ltd.; and National Paper

Product Quality Supervision Inspection Center.

Chief drafting organizations of this Document. Yuan Taojing, Lu Kesen, Lailu Nanxiang, Wang

Jin, Dai Huafen, Lian Jiaqi, Mao Dongsheng, Tiao Rongchao, Teng Bubin, Zhang Meng, and

Wang Xinting.

The historical editions replaced by this Document are as follows.

--- GB 462-1964 Paper and Board - Determination of Moisture Content was first-time

published in 1964; first-time revised in 1979; second-time revised in 1989; third-time

revised in 2003;

--- When fourth-time revised in 2008, it combines GB/T 741-2003 Pulps - Determination of

Moisture Content (the historical editions replaced by GB/T 741-2003 included GB 741-

1965, GB/T 741-1979, and GB/T 741-1989);

--- It is fifth-time revised hereby.

Paper, Board and Pulps - Determination of Moisture

Content of Analytical Sample

WARNING. The methods specified in this Document involve the use of nanomaterials.

Care shall be taken to ensure that relevant precautions and guidelines for nanotechnology

laboratory safety and best practices are followed.