GB/T 42483-2023 (English Version)

Standard No.: GB/T 42483-2023
Language: Chinese, Available in English version
Release Date: 2023
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 42483-2023

Scope: This document describes the test instrument, specimen, test procedure, result calculation and test report for the determination of thermal conductivity of wood by heat flow method. This document is applicable to the determination of thermal conductivity of wood in radial, chordal and longitudinal directions.

Introduction

GB/T 42483—2023 Standard Overview

This standard specifies in detail the determination method of wood thermal conductivity, using the heat flow method as the core test method. It is suitable for measuring the radial, chordal and longitudinal thermal conductivity of wood, and provides a scientific basis for the evaluation of wood thermal insulation performance.

Test Principle and Methods

Project Dimensions	Specific Requirements	Technical Details
Test Principle	The heat flow method is based on a unidirectional heat flow passing vertically through the specimen under a stable state	The thermal conductivity of wood is calculated by measuring the temperature difference and heat flow between the hot and cold ends
Test Method	The heat flow meter plate is in close contact with the specimen	The temperature difference is measured using a thermocouple to control the temperature difference fluctuation within the allowable range
Calculation Formula	Thermal conductivity λ = q · d / (TH - TC)	Where q is the heat flux density, d is the sample thickness, TH and TC are the hot end and cold end temperatures respectively

Test Instrument and Equipment Specifications

The heat flux meter board is the core component of the test system. Its thermal conductivity is required to be no less than 50 W/(m·K), and its surface flatness is controlled within 0.25 mm/m.

The heating system and cooling system must have precise temperature control capabilities (error ±0.5°C) to ensure a stable test environment.

Specimen preparation and requirements

Practical application case analysis

Taking radial specimens as an example, sampling should be carried out in accordance with GB/T1927.2-2021 standard, and its moisture content should be ensured to be in an air-dry or absolute dry state. Dimensional measurement and quality verification should be carried out before testing, and data should be recorded for subsequent calculations.

Implementation suggestions

Select heat flow meter board and temperature sensor that meet the requirements
Strictly control the moisture content of the specimen to ensure the accuracy of the test results
Establish a data recording and analysis system to facilitate subsequent statistics and comparison

Summary and Outlook

GB/T 42483-2023 standard provides a scientific basis for the determination of thermal conductivity of wood. In the future, the influence of different wood species and processing technology on thermal conductivity can be further studied.

GB/T 42483-2023 Referenced Document

GB/T 1927.2 Test methods for physical and mechanical properties of small clear wood specimens—Part 2: Sampling methods and general requirements
GB/T 1927.4 Test methods for physical and mechanical properties of small clear wood specimens—Part 4: Determination of moisture content
GB/T 1927.5 Test methods for physical and mechanical properties of small clear wood specimens—Part 5: Determination of density
GB/T 4132 Adiabatic terminology*， 2023-09-07 Update
LY/T 1788 Wood properties terminology*， 2023-06-19 Update

GB/T 42483-2023 history

2023 GB/T 42483-2023 Determination of thermal conductivity of wood by heat flow method