GB/T 11901-1989Water quality--Determination of suspended substance--Gravimetric method (English PDF)

2 Definition

The suspended substance in water indicates the solid substance that water sample passes through the filter membrane with pore size of 0.45µm, trapped on the filter membrane, dried to constant weight at 103~105°C.

3 Reagents

Distilled water or water with equal purity.

4 Instruments 4.1 Commonly-used laboratory equipment and the following instruments.

4.2 All-glass microporous membrane filter.

4.3 CN-CA filter membrane with pore size of 0.45µm, diameter of 60mm.

4.4 Suction filter bottle, vacuum pump.

4.5 Toothless flat-nose tweezers.

5 Sampling and Sample Storage 5.1 Sampling

5.2 Sample storage The collected water sample shall be analyzed and tested as soon as possible. If placed, it shall be stored in the 4°C refrigerating box; but not exceeding a maximum of 7 days. NOTE: no protective agent is allowed to be added, so as to prevent the distribution balance of substance between solid and liquid.

6 Procedures 6.1 Preparation of filter membrane

Clip the microporous filter membrane by flat-nose toothless tweezers; place into the weighing bottle with constant weight; move into bake oven to dry for half an hour at 103~105°C; after that take it out and place into the drier to cool off to the room temperature; weigh it; repeatedly dry, cool off, weigh till the weight difference between two weight measurement is <=

0.2 mg. Correctly place the microporous filter membrane with constant weight onto the filter membrane tray of the membrane filter (4.1); cover with supporting funnel; then use clip to fix. Use distilled water to wet the filter membrane, and continued to suck and filter.

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About this edition

GB/T 11901-1989 is the current edition. It was issued on 3 November 1989 and has been in force since 1 July 1990.

The interval between issue and effect is the transition period. It exists so that producers, laboratories and buyers can requalify products, revise procedures and use up documentation before the new text becomes the one that applies. The date on this page is the official one from the record of the Standardization Administration.

Classification and status

GB/T 11901-1989 is classified under ICS (ICS). ICS is the International Classification for Standards, the same scheme used by ISO and by the national bodies of most countries, which is what allows a Chinese standard to be placed beside its foreign counterparts on subject rather than on number.

Its Chinese Standard Classification code is CCS Z16. CCS is the domestic scheme, a letter for the sector and two digits for the subject within it, and it is the code by which the standard is filed and searched in China.

The GB/T prefix marks a recommended national standard. It is not, in itself, law: it becomes binding when a contract names it, when a regulation or a mandatory standard refers to it, or when a producer declares conformity with it. In practice that covers most of the cases in which it will be read — a purchase specification, an inspection agreement or a certification scheme.

How a Chinese national standard is set out

Chinese national standards are drafted to the rules of GB/T 1.1, which fixes the order in which a standard is set out. The document opens with a foreword recording the issuing bodies, the relationship to any previous edition and the technical committee responsible for it. Clause 1 is the scope. Clause 2 lists the normative references — the other standards that have to be applied together with this one, and without which its requirements cannot be met. Clause 3 gives the terms and definitions. The technical clauses follow: the requirements themselves, the test or measurement methods by which conformity is established, the inspection rules that say how a lot is sampled and judged, and, for a product standard, the provisions on marking, packaging, transport and storage. Annexes, normative or informative, come last.

GB/T 11901-1989 runs to 8 pages in the English translation. What is delivered is the complete document in that order: every clause, every table, every figure and every annex of the Chinese original, with the same numbering, so that a reference to a clause number in a contract or a test report points to the same place in both languages.

About this English translation

The English edition of GB/T 11901-1989 is a full translation of the official Chinese text, not a summary, an abstract or a machine rendering left unchecked. Clause and subclause numbers, table and figure numbers and annex letters are those of the original, because they are what a specification, a purchase order or a test report cites.

Technical terms are translated against the vocabulary standards of the same field, so that a term used in GB/T 11901-1989 reads the same way as in the other Chinese standards it is used beside. Where a term has an established English form in an ISO or IEC document on the same subject, that form is used; where China's term has no foreign counterpart, it is translated literally and the Chinese is kept alongside it rather than replaced by an approximation.

Quantities, units and symbols are carried over unchanged. Chinese standards use SI, so a value in the translation is the value in the original document, not a conversion, and a limit read from the English text is the limit that will be applied by a Chinese inspection body reading the Chinese one.

This page is compiled from the official publication record: the standard number and both titles, the issuing bodies, the dates of issue and effect, the ICS and CCS classification. The requirements, limits, tables and test conditions are in the document itself.