ISO 649-2-1981 PDF

Full title and description

St ISO 649-2-1981 — Laboratory glassware — Density hydrometers for general purposes — Part 2: Test methods and use. Specifies test methods, apparatus, measurement and temperature-reading procedures, application of corrections and illustrative vessel drawings for use with general-purpose density hydrometers.

Abstract

The standard defines procedures for determining density using laboratory hydrometers: required apparatus, how to read density and temperature, the corrections to apply (temperature and calibration), and recommended vessels/dimensions and handling for accurate measurement. It complements Part 1, which gives the specification for the hydrometers themselves.

General information

• Status: Withdrawn / cancelled (withdrawal recorded in ISO lifecycle).
• Publication date: 1981-09 (Edition 1, September 1981).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 17.060 — Measurement of volume, mass, density, viscosity.
• Edition / version: Edition 1 (1981).
• Number of pages: 9 pages (technical pamphlet).

Scope

This part of ISO 649 specifies test methods and instructions for the use of density hydrometers intended for general laboratory purposes. It covers the general procedure for density determination, necessary apparatus (including illustrative vessel drawings), reading and reporting of density and temperature, and the application of correction factors to obtain standardized results. It is intended to be used together with ISO 649-1 (specification of the hydrometers).

Key topics and requirements

• Definitions and scope of application for general-purpose density hydrometers.
• Required apparatus and sample vessels, including recommended dimensions and drawings.
• Procedures for reading hydrometer scales and measuring sample temperature.
• Calculation and application of temperature and calibration corrections to measured densities.
• Accuracy, repeatability considerations and recommended handling/storage practices.
• Normative references including related laboratory glassware standards (e.g., pyknometers, graduated cylinders) used in density measurement.

Typical use and users

Used by chemical and physical testing laboratories, quality control departments, calibration laboratories, laboratory-glassware manufacturers and instrument makers. Typical activities include routine density determinations, instrument verification, user training on hydrometer use, and specification checks when producing or procuring hydrometers and associated vessels.

Related standards

Directly related to ISO 649-1 (Laboratory glassware — Density hydrometers for general purposes — Part 1: Specification). Normative references commonly cited include ISO 3507 (pyknometers) and ISO 4788 (graduated measuring cylinders). National or regional catalogues and sellers may carry archived copies or national adoptions.

Keywords

density hydrometer, laboratory glassware, density measurement, hydrometer test methods, temperature correction, pyknometer, graduated cylinder, ISO 649-2, density determination.

FAQ

Q: What is this standard?

A: ISO 649-2:1981 is Part 2 of ISO 649 covering test methods and the use of general-purpose laboratory density hydrometers.

Q: What does it cover?

A: It covers apparatus, procedures for reading density and temperature, calculations and corrections to report standardized densities, and illustrative vessel drawings for carrying out measurements. It complements Part 1 of ISO 649, which specifies the hydrometers themselves.

Q: Who typically uses it?

A: Laboratory technicians, metrology and calibration staff, QC personnel in chemical and industrial labs, and manufacturers or purchasers of hydrometers and laboratory glassware.

Q: Is it current or superseded?

A: ISO 649-2:1981 is listed as withdrawn in the ISO lifecycle. Users should consult national standards bodies or the ISO catalogue for current replacements, national adoptions, or more recent guidance on density measurement methods.

Q: Is it part of a series?

A: Yes — it is Part 2 of the ISO 649 series for density hydrometers; Part 1 provides the product specification. Historical references include ISO/R 649 (1968), which was superseded by the 1981 parts.

Q: What are the key keywords?

A: Density hydrometer, laboratory glassware, density measurement, temperature correction, pyknometer, ISO 649-2.