On the application of buoyancy correction in the cup test measurement

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21720%2F24%3A00377183" target="_blank" >RIV/68407700:21720/24:00377183 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21110/24:00377183

Výsledek na webu

<a href="https://doi.org/10.1016/j.buildenv.2024.111902" target="_blank" >https://doi.org/10.1016/j.buildenv.2024.111902</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.buildenv.2024.111902" target="_blank" >10.1016/j.buildenv.2024.111902</a>

Jazyk výsledku

angličtina

Název v původním jazyce

On the application of buoyancy correction in the cup test measurement

Popis výsledku v původním jazyce

The water vapour permeability of building materials is often measured using the cup method. One of usual corrections applied to the measured data is correction for the ambient air buoyant force acting on the cup assembly during weighing, the so-called `buoyancy correction’. Although the mathematical formula for the correction is well known, there are two distinct ways for its application to the cup test, which depend on the air permeability and flexibility of the tested sample. The magnitude of the correction can be twice different for the two approaches. This study, at first theoretically describes the use of buoyancy correction for cups with different samples. Then, presents results of the measurement of the air pressure inside cups with different samples which support the theoretical assumptions. Finally, based on numerical simulation, were established limits of use of the calculated buoyancy correction. Many samples of building materials are enough air permeable (air permeance higher than 1 x 10-10 kg/(m2sPa)) or flexible to maintain the air pressure and density in the cup close to ambient conditions. Cups with these samples can be corrected by applying the buoyancy correction to the volume of the air-impermeable parts of the cup assembly. If the air permeance of the sample is lower, the possible residual error after the application of correction can be ±3–7 mg/dm2 of the cup mouth area. The application of buoyancy correction can reduce the measurement time, especially for samples with a higher vapour resistance.

Název v anglickém jazyce

On the application of buoyancy correction in the cup test measurement

Popis výsledku anglicky

The water vapour permeability of building materials is often measured using the cup method. One of usual corrections applied to the measured data is correction for the ambient air buoyant force acting on the cup assembly during weighing, the so-called `buoyancy correction’. Although the mathematical formula for the correction is well known, there are two distinct ways for its application to the cup test, which depend on the air permeability and flexibility of the tested sample. The magnitude of the correction can be twice different for the two approaches. This study, at first theoretically describes the use of buoyancy correction for cups with different samples. Then, presents results of the measurement of the air pressure inside cups with different samples which support the theoretical assumptions. Finally, based on numerical simulation, were established limits of use of the calculated buoyancy correction. Many samples of building materials are enough air permeable (air permeance higher than 1 x 10-10 kg/(m2sPa)) or flexible to maintain the air pressure and density in the cup close to ambient conditions. Cups with these samples can be corrected by applying the buoyancy correction to the volume of the air-impermeable parts of the cup assembly. If the air permeance of the sample is lower, the possible residual error after the application of correction can be ±3–7 mg/dm2 of the cup mouth area. The application of buoyancy correction can reduce the measurement time, especially for samples with a higher vapour resistance.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20101 - Civil engineering

Projekt

<a href="/cs/project/GA20-12941S" target="_blank" >GA20-12941S: Růst plísní na povrchové vrstvě rostlého dřeva za proměnných okrajových podmínek</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Building and Environment

ISSN

0360-1323

e-ISSN

1873-684X

Svazek periodika

266

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

15

Strana od-do

—

Kód UT WoS článku

001321269300001

EID výsledku v databázi Scopus

2-s2.0-85204482747