A sodium analyzer should generally be used in conjunction with conductivity measurement. Because conductivity is non-specific, it cannot distinguish between contaminants and water treatment chemicals such as ammonia or phosphates. A sodium analyzer is more specific and more sensitive. It can detect when a cation exchanger needs to be regenerated, whereas conductivity cannot "see" the sodium until the levels are too high because of the high background conductivity of pure water. The sensitivity of a sodium analyzer is critical, because contaminants in steam become many orders of magnitude more concentrated when they accumulate in the first condensation droplets in turbines, where they are very corrosive.