ISO 2581-1975 rus PDF

Full title and description

St ISO 2581-1975 rus — Russian-language edition/translation of ISO 2581:1975, titled "Rigid cellular plastics — Determination of apparent thermal conductivity by means of a heat‑flow meter". The document specifies the apparatus, specimen preparation, calibration and test procedure for measuring the apparent thermal conductivity of rigid cellular plastics (foam materials) using a heat‑flow meter method. A Russian text (rus) version is circulated commercially or as a national translation; the original International Standard was published by ISO in 1975.

Abstract

ISO 2581:1975 defines a laboratory method using a heat‑flow meter to determine the apparent thermal conductivity of rigid cellular plastics. It covers required test equipment (heat‑flow meter apparatus), calibration procedures, specimen conditioning and preparation, measurement steps, calculation of results and presentation of the test report. The original 1975 edition is short (7 pages) and was later subject to an erratum; its test approach was superseded by a broader heat‑flow meter standard in 1991.

General information

• Status: Withdrawn (superseded).
• Publication date: 15 November 1975 (erratum published 15 December 1981).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 83.100 (Plastics).
• Edition / version: Edition 1 (1975); Russian translation indicated as "rus" for language version.
• Number of pages: 7 pages (original ISO edition).

Scope

Specifies a laboratory test method (heat‑flow meter technique) for determining the apparent thermal conductivity of rigid cellular plastics (rigid foams). The scope includes the description of the heat‑flow meter apparatus, calibration with reference specimens, specimen dimensions and conditioning, steady‑state measurement procedure, calculations to derive apparent thermal conductivity (or thermal resistance), and reporting conventions required to present meaningful, reproducible results for comparative evaluation of foam materials.

Key topics and requirements

• Definition and objective: measurement of apparent thermal conductivity of rigid cellular plastics using a heat‑flow meter.
• Apparatus description: heat‑flow meter plates, plate temperature control, heat flux transducers and data acquisition considerations.
• Calibration: use of calibration specimens/standards and procedures to convert meter output to heat flux.
• Specimen preparation and conditioning: dimensions, surface preparation and equilibrium moisture/temperature conditioning.
• Test procedure: establishing steady state, temperature settings, measurement sequence and timing.
• Calculations and reporting: formulas to compute apparent thermal conductivity, expression of results (mean temperature, temperature difference, units), and required test report items.
• Limitations and uncertainties: method is a comparative (secondary) method and requires suitable calibration and control of edge losses and measurement uncertainty.

Typical use and users

Used by materials test laboratories, manufacturers of rigid cellular plastics (insulating foams), product development and quality control teams, building‑materials specifiers and regulatory test bodies. Typical applications include thermal characterization for insulation performance, R&D comparisons of foam formulations, conformity checks for product claims, and input data for thermal calculations in building and industrial applications.

Related standards

Key related and successor standards include ISO 8301:1991 (Thermal insulation — Determination of steady‑state thermal resistance and related properties — Heat flow meter apparatus), which superseded ISO 2581:1975; ISO 9869‑1:2014 (in‑situ heat‑flow meter method for building elements) for on‑site measurement; and regional/national equivalents such as ASTM C518 (heat‑flow meter test method for thermal transmission properties). These documents describe similar heat‑flow meter techniques, broader scopes or in‑situ procedures and provide updated apparatus and reporting guidance.

Keywords

ISO 2581, rigid cellular plastics, rigid foam, heat‑flow meter, apparent thermal conductivity, thermal conductivity, thermal resistance, calibration, test method, Russian translation

FAQ

Q: What is this standard?

A: ISO 2581:1975 is an International Standard that defines a laboratory method using a heat‑flow meter to determine the apparent thermal conductivity of rigid cellular plastics. The "St ISO 2581-1975 rus" label indicates a Russian‑language edition or translation of that standard.

Q: What does it cover?

A: It covers apparatus requirements (heat‑flow meter), calibration with reference specimens, specimen preparation and conditioning, steady‑state measurement procedure, calculations to obtain apparent thermal conductivity (and related thermal resistance), and reporting of results.

Q: Who typically uses it?

A: Materials and product testing laboratories, foam manufacturers (R&D and quality control), building‑materials engineers, certification bodies and others needing comparative thermal property data for rigid cellular plastics.

Q: Is it current or superseded?

A: ISO 2581:1975 was published on 15 November 1975 and an erratum was issued on 15 December 1981. It has been withdrawn and superseded by ISO 8301:1991 (published August 1991), which provides a more general and updated heat‑flow meter method for thermal insulation and related materials.

Q: Is it part of a series?

A: It belongs to the family of ISO methods addressing thermal properties and heat‑flow meter techniques. Closely related documents include ISO 8301:1991 (replacement) and later ISO standards on in‑situ and laboratory heat‑flow meter methods (for example ISO 9869‑1:2014).

Q: What are the key keywords?

A: Rigid cellular plastics, rigid foam, heat‑flow meter, apparent thermal conductivity, thermal resistance, calibration, test method, ISO 2581, Russian translation.