The test is conducted by circulating deionised water through the test item, measuring the change in the oxygen content. The first step is to reduce the oxygen content of the water to a minimum. This is done by flushing the water with a gas of a defined concentration (helium or nitrogen).
As soon as the oxygen has been removed from the water, the almost oxygen-free water is circulated through the test item.
The oxygen in the air surrounding the test item will tend to diffuse through the pipe walls of the test item to dissolve in the test water. This will gradually result in an increase in the oxygen content. The rate of this increase indicates the permeability of the test item. As the test also has to be carried out at higher temperatures, the device has been equipped with an adjustable heating and cooling system. This makes it possible to carry out the test at a given temperature (between 40 and 85°C).
To ensure that the air surrounding the test item has the same temperature as the test water, the test item is rolled up and placed into a climate chamber.
The oxygen content is measured in a cooled bypass equipped with a highly sensitive oxygen sensor (at least 0.1 mg/m³ , corresponding to 0.1 ppb). All water-bearing components are made of rust-proof material and are pressure-resistant up to 3 bar.
Operation takes place manually via ball valves, but the device can also be equipped with electronic controls.
The measurements are usually evaluated using special evaluation software that graphically displays the oxygen content over time, incorporating all the important parameters and automatically calculating the results. Test items of up to 25 mm can be tested. An air pressure meter and a drum to wind up the test items form part of the delivery scope.
The device works without chemical additives, which means that it cannot influence the oxygen content.
For the past 40 years, IPT has been an international leader in the construction of test systems for pipes and plastics. This enables our business partners to profit from our wide range of experience in developing complex laboratory system technologies.
If you would like to know more, you can download our data sheet or call us at: +49.8237.966-0. We will be pleased to provide more information.
