【Instrument Encyclopedia】Water Vapor Transmission Rate Tester

1. Introduction

Water vapor permeability tester, also known as moisture permeability meter, moisture permeability tester or water vapor permeability tester, is a device specially used to determine the water vapor transmission rate of various film samples, such as plastic film, composite film and other films, sheet materials. It is of great significance for controlling and adjusting the technical indicators of materials to meet the different needs of product applications.

Second, the principle of the instrument

The principle of the water vapor transmission rate tester is mainly based on the principle of difference in the process of water vapor transfer. The tester consists of a test chamber, a controller, and a differential pressure gauge. The interior of the test chamber is divided into two sections: the upper part is the relative humidity setting section, and the lower part is the test section where the test sample is located. The specimen is placed underneath the test chamber and above it is provided with a flow-through gas to measure the relative humidity. During the test, the water vapor transmission rate of the test sample was calculated by setting different relative humidity values to form a pressure difference to promote the diffusion of water vapor molecules from the high humidity area to the low humidity area.

3. Instrument classification

According to the different test principles, water vapor transmission rate testers can be divided into the following types:

1. Gravimetric moisture permeameter: also known as cup method moisture permeability meter or gravimetric method moisture permeability. It adopts the test principle of the weighing method of the breathable cup, and calculates the water vapor transmission rate and other parameters of the sample by measuring the change of the weight of the breathable cup with time.
2. Electrolytic Moisture Permeameter: Using the electrolytic sensor test principle, the permeated water vapor is carried to the sensor by the flowing dry nitrogen on the low humidity side, and the water vapor transmission rate is determined by electrolysis.
3. Infrared detection method moisture permeability: using the infrared sensor method test principle, using infrared rays to detect the water vapor transmittance rate.
4. Humidity hygroscopic meter: The sample to be tested is sandwiched between the dry and wet chambers at a constant temperature, and the changes in the humidity in the chamber are analyzed through the sensor in the test chamber to obtain the water vapor permeability rate and moisture permeability coefficient of the sample.

Fourth, the operation steps

The operation steps of the water vapor transmission rate tester are roughly as follows:

1. Specimen preparation: Select specimens that meet the test requirements and ensure that the specimens are free of defects or damage.
2. Specimen mounting: Properly install the specimen in the fixture or test chamber of the tester, ensure that the specimen is in close contact with the fixture, and adjust the specimen position so that it is in a suitable test state.
3. Set test parameters: Set appropriate test parameters, such as test time, temperature, humidity, etc., according to the test requirements.
4. Start the test: Start the tester and start the test of the water vapor transmission rate. The tester records changes in the water vapor transmission rate of the sample.
5. End Test: The tester will automatically stop when the test reaches the set time or other stopping conditions are met. At this point, the test data can be saved.
6. Analyze the test results: Analyze the saved test data, including the maximum water vapor transmission rate, average water vapor transmission rate and other indicators, to evaluate the water vapor barrier performance of the sample.

5. Equipment application

Water vapor transmission rate tester has a wide range of applications, including but not limited to the following:

1. Packaging material research: used to evaluate the water vapor barrier performance of various packaging materials, such as plastic films, composite films, etc.
2. Quality control: In the production process, it is used to monitor the water vapor transmission rate of products to ensure the consistency and stability of product quality.
3. R&D and new product development: In the R&D phase, it is used to evaluate the water vapor barrier properties of new materials to guide product design and material selection.
4. Academic research: It is used in the field of academic research to explore the transport mechanism of water vapor in materials and provide valuable data for the field of materials science.

The above water vapor permeability tester instrument encyclopedia information is compiled and released by Jinan Languang Electromechanical Technology Co., Ltd., if you need to know more about the technical information of related equipment, you can leave a message or contact the corresponding manufacturers to communicate.