Many applications in science and industry require an apparatus that creates a controlled amount of a fluid introduced into another fluid. For instance, some material corrosion testing applications require such an apparatus to determine the reaction of a material over time upon exposure to a controlled corrosive vapor-gas mixture. Tests typically are performed using a higher vapor concentration of the vapor-gas mixture in an effort to decrease the duration of the test. Data are then extrapolated to model the material’s reaction over time. However, because the results are extrapolated, any error caused by an imprecisely controlled vapor-gas mixture will be magnified. Thus, an apparatus that creates a controlled testing environment with a gas having a precise flow rate and a precisely controlled vapor-gas mixture is critical to ensure the accuracy of these types of tests.
The Extrans Permeation Measurement System is a customizable system for testing the behavior and uniformity of polymers and other materials. The system can be used to determine permeation rates using variable temperatures, total pressures, differential pressures, and mechanical deformations as well as adjustable concentration levels for gases and liquids. Extrans supports permeation testing from liquid-to-gas or from gas-to-gas phases.
Thermally induced permeation through a permeable tube is used to mix a fluid from outside the tube with a second fluid flowing through the tube. Mixture ratios may be controlled by adjusting the temperature of the first fluid, or by adjusting the pressure drop through the permeable tube. The combination of a back pressure control valve and a differential regulator is used to control the output pressure of the blended fluid. The combination of the back pressure control valve and differential regulator provides superior flow control of the second dry gas. A valve manifold system may be used to mix multiple fluids, adjust the volume of blended fluid produced, and further modify the mixture ratio.
Applications include container analysis and design for storage of food, munitions, and moisture-reactive materials; materials analysis of conformal coatings for electrical circuit components used in marine, aerospace, defense, and other critical applications; corrosion studies; and coating, film, and paint evaluation.