ISO 8302-1991 PDF

Full title and description

ISO 8302:1991 — Thermal insulation — Determination of steady-state thermal resistance and related properties — Guarded hot plate apparatus. This International Standard specifies the guarded hot plate method for measuring steady-state heat transfer through flat slab specimens and the calculation of thermal resistance, thermal conductance and related properties. Annex A is normative (integral); Annexes B, C and D are informative.

Abstract

ISO 8302:1991 defines an absolute (primary) laboratory method using a guarded hot plate to determine the steady-state thermal resistance and related properties of flat slab thermal-insulation specimens. The method requires measurements of dimensions, temperatures and supplied electrical power, and includes requirements for apparatus, specimen conditioning, test procedure, data reduction, uncertainty and reporting.

General information

• Status: Published — International Standard (confirmed in ISO systematic review process).
• Publication date: August 1991 (first edition).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 27.220 — Heat recovery. Thermal insulation.
• Edition / version: Edition 1 (1991).
• Number of pages: 47 pages (English edition).

Scope

Specifies the guarded hot plate apparatus and procedure for measuring steady-state thermal resistance, thermal conductance and related properties of homogeneous and layered flat-slab insulation specimens under controlled laboratory conditions. The standard sets requirements for apparatus design (meter plate, guard heater, cold plates), specimen mounting and dimensions, environmental and test temperatures, stabilization and steady-state criteria, data acquisition and calculations. Annex A is an integral part of the standard; Annexes B–D provide supplementary information.

Key topics and requirements

• Guarded hot plate apparatus: meter plate, guard heater, cold plates and insulation arrangement.
• Specimen preparation and dimensions (single- and double-sided modes where applicable).
• Test conditions: temperature gradients, stabilization/steady-state criteria and environmental control.
• Measurement methods: temperature sensing, electrical power measurement and reduction to heat flux.
• Calculations: thermal resistance, thermal conductance, mean thermal conductivity and reporting conventions.
• Calibration, verification and uncertainty analysis for absolute measurements.
• Limits and applicability: expected ranges, minimum measurable resistance and cautions on thin/very conductive specimens.
• Reporting requirements and required annex material (A normative; B–D informative).

Typical use and users

Used primarily by accredited testing laboratories, research institutes (including national metrology labs), insulation and materials manufacturers, product certification bodies and building-physics consultants to characterise thermal-insulation materials and assemblies. It is applied to material R-value / thermal conductivity determination, instrument verification and interlaboratory comparisons. Guarded-hot-plate results are often used as primary reference measurements to validate heat-flow-meter or other comparative methods.

Related standards

Commonly referenced alongside other thermal-insulation test methods and vocabulary standards, including ISO 8301 (heat flow meter apparatus), ISO 8990 (calibrated and guarded hot box), ISO 8497 (pipe insulation test methods), ISO 9229 (vocabulary) and regional/industry equivalents such as ASTM C177 (guarded-hot-plate test method) and ASTM C518 / EN 12667 (heat flow meter methods and related EN standards). These documents together form the set of steady-state laboratory test methods for thermal transmission properties.

Keywords

guarded hot plate, thermal resistance, thermal conductivity, steady-state measurement, thermal insulation, heat flux, ISO 8302, test method, calibration, uncertainty.

FAQ

Q: What is this standard?

A: ISO 8302:1991 is an ISO International Standard that specifies the guarded hot plate method for determining steady-state thermal resistance and related thermal properties of flat-slab insulation specimens.

Q: What does it cover?

A: It covers apparatus design and configuration, specimen preparation, test procedures to reach steady state, measurement and data-reduction procedures, calculation of thermal resistance/conductivity and requirements for calibration, uncertainty and reporting. Annex A is normative and Annexes B–D are informative.

Q: Who typically uses it?

A: Accredited test laboratories, national metrology institutes, insulation manufacturers, certification bodies and building-physics researchers use ISO 8302 for high-accuracy characterisation and as a reference method for validating comparative instruments.

Q: Is it current or superseded?

A: ISO 8302 was published in August 1991 (first edition) and is listed as published by ISO. The ISO lifecycle indicates the edition has been subject to periodic review; the standard remains the recognized ISO method for guarded hot plate testing unless and until ISO publishes a superseding edition. For the latest status confirmation consult the ISO catalogue or national standards body.

Q: Is it part of a series?

A: Yes — ISO 8302 is part of the group of ISO methods for steady-state determination of thermal transmission properties (including ISO 8301 for heat flow meter methods and related ISO documents for other geometries and apparatus). These standards together provide complementary test methods for thermal-insulation characterisation.

Q: What are the key keywords?

A: Guarded hot plate, thermal resistance, thermal conductivity, steady-state, heat flux, insulation testing, calibration, uncertainty.