GB/T 44440-2024 Thermal-insulating materials - Determination of long-term water absorption by diffusion
1 Scope
This International Standard specifies equipment and procedures for determining the long-term water absorption of test specimens by diffusion. It is intended for use with thermal-insulation products. It is designed to simulate the absorption of water by products subjected for a long period of time not only to high relative humidity, approximating to 100 %, on both sides, but also to a water vapour pressure gradient, as experienced by e.g. inverted roof or unprotected ground insulation.
The test is not applicable to all types of thermal-insulation product. The product standard should normally state whether this test is applicable to a particular product.
Note: For unprotected ground insulation, a lower temperature might, when more data is available, replace the test temperature of 50 °C currently specified in this International Standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 472 Plastics - Vocabulary
ISO 1923 Cellular plastics and rubbers - Determination of linear dimensions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 apply.
4 Principle
The long-term water absorption by diffusion is determined by measuring the increase in mass of a test specimen when it is subjected to a water vapour pressure difference and temperature gradient between its upper and lower surfaces for a period of 28 days.
Standard
GB/T 44440-2024 Thermal-insulating materials—Determination of long-term water absorption by diffusion (English Version)
Standard No.
GB/T 44440-2024
Status
valid
Language
English
File Format
PDF
Word Count
7000 words
Price(USD)
210.0
Implemented on
2025-3-1
Delivery
via email in 1~3 business day
Detail of GB/T 44440-2024
Standard No.
GB/T 44440-2024
English Name
Thermal-insulating materials—Determination of long-term water absorption by diffusion
GB/T 44440-2024 Thermal-insulating materials - Determination of long-term water absorption by diffusion
1 Scope
This International Standard specifies equipment and procedures for determining the long-term water absorption of test specimens by diffusion. It is intended for use with thermal-insulation products. It is designed to simulate the absorption of water by products subjected for a long period of time not only to high relative humidity, approximating to 100 %, on both sides, but also to a water vapour pressure gradient, as experienced by e.g. inverted roof or unprotected ground insulation.
The test is not applicable to all types of thermal-insulation product. The product standard should normally state whether this test is applicable to a particular product.
Note: For unprotected ground insulation, a lower temperature might, when more data is available, replace the test temperature of 50 °C currently specified in this International Standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 472 Plastics - Vocabulary
ISO 1923 Cellular plastics and rubbers - Determination of linear dimensions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 apply.
4 Principle
The long-term water absorption by diffusion is determined by measuring the increase in mass of a test specimen when it is subjected to a water vapour pressure difference and temperature gradient between its upper and lower surfaces for a period of 28 days.
