Third, it does not have enough time for equilblio determination. By the same author: Xcel Energy. In the gift, tests for samples of property of high barrier are emphasized; still exists if difficulties to test samples of high tax of transmission. This must be noticed especially that the determination of equilblio of transmission menciada on is point of key for test of barrier property. The conditions for determination must rigorously be respected to prevent false judgment or until ending before reaching the equilblio of transmission. For samples of property of average and high barrier, some hours are necessary for equilblio.
But for materials of property of barrier low, that is material of high tax of transmission, as material not weaveeed and fabrics and separating films of the battery, them they relatively reach the equilblio of transmission in a very short period. Therefore, the equilblio determination of the periodic sample it is cancelled in the norms of test of tax of water vapor transmission for fabrics. For materials of high tax of transmission, the obstacles of test are mainly grown amount of transmission of gas and greater tax of gas flow. For example, the determination of equilblio for test of tax of gas transmission with pressure-differential method depends on tax of alteration of pressure of gas of inferior chamber. When it purges gas of test in the superior chamber to test sample of high tax of transmission, the pressure of inferior chamber would grow quickly due to property of high transmission of sample. How much to the bequeather of tax of gas transmission with method of equal pressure, the determination depends on concentration of oxygen in cmra of test, that would be measured directly by the sensor. But when to test materials of extremely high tax of transmission, concentration of oxygen in the test chamber exceeds value maximum of scope of measurement of sensor and influences its life.