1.1 ,This test method covers the determination of the performance of mixed bed ion exchange resin cartridges in the active form when used for deionization. The test can be used to determine the initial capacity of unused cartridges or the remaining capacity of used cartridges. In this case performance is defined as ion exchange capacity (or throughput) to two defined endpoints. The method does not measure organics and does not attempt to determine the ultimate water quality attainable by the cartridge.