Procedure and device for the measurement of water vapor transfer through textiles and other plate-like materials
First Claim
1. A process for simultaneous determination of two or more characteristics related to water vapor transfer through plate-like samples, in particular textile materials, which requires the steps of:
- (a) arranging the test sample atop of a container of water at a certain temperature located at the bottom of a measuring chamber possessing a certain air volume in an air chamber at a certain air temperature and a defined starting humidity;
(b) measuring the humidity change in the measuring chamber over a time interval which occurs when water vapor penetrates the test sample as a result of the difference in water vapor pressure between the water bath and the chamber air;
(c) calculating two or more characteristics related to water vapor transfer using the absolute humidity gain in the air volume within the measuring interval, the difference in water vapor pressure and a thermal measurement of any evaporative heat flux evolved during the water vapor transfer thru such textile test sample.
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Abstract
The invention provides a method for measurement of characteristics related to water vapor transfer through plate-like material samples, in particular textile materials, and a measuring unit device with a water container, a water container atmosphere or headspace, air chamber, and measuring chamber, where the water container headspace and air chamber are separated by such plate-like material sample for carrying out such measurements under stationary air flow conditions according to detecting an absolute humidity increase of 1% in an air chamber atmosphere, and where determinations of water vapor transmission rate, water vapor resistance, water vapor permeability and water vapor pressure differential across the plate-like material sample are obtained via use of appropriate sensors installed within the housing of such testing device, including air temperature and humidity sensors, water temperature sensor, and an evaporative heat flux thermal sensor.
14 Citations
16 Claims
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1. A process for simultaneous determination of two or more characteristics related to water vapor transfer through plate-like samples, in particular textile materials, which requires the steps of:
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(a) arranging the test sample atop of a container of water at a certain temperature located at the bottom of a measuring chamber possessing a certain air volume in an air chamber at a certain air temperature and a defined starting humidity; (b) measuring the humidity change in the measuring chamber over a time interval which occurs when water vapor penetrates the test sample as a result of the difference in water vapor pressure between the water bath and the chamber air; (c) calculating two or more characteristics related to water vapor transfer using the absolute humidity gain in the air volume within the measuring interval, the difference in water vapor pressure and a thermal measurement of any evaporative heat flux evolved during the water vapor transfer thru such textile test sample. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A measuring unit for measuring characteristics related to water vapor transfer through test samples under stationary air flow conditions, said measuring unit consisting of an open liquid water supply measuring chamber with an overhead air space of chamber air, within which device the following components are situated during an assessment of water vapor permeability properties for said test samples:
a container completely full of water serving also as a water bath, a sample holder for ensuring proper positioning of said test samples, a means for performing a sample exchange between different pairs of said test samples, a temperature measuring sensor for said water bath, air temperature and humidity measuring sensors for said chamber air as well as means used to vary chamber air conditions such as humidity and temperature where said container of water is situated beneath said test samples and is disposed at the bottom of said measuring chamber. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
Specification