The HYDROKIT® HK Series is an effective "Go, No-Go" field test designed to periodically check for free water, which is removed to ppm levels by properly operating filter/ separators, Aquacon®, and monitor vessels. Samples are normally taken downstream of the vessel, but they can also be taken at other points in the fuel distribution system. The HYDROKIT® is designed to indicate free water in excess of 30* ppm by changing the powder contained in the sample tube to a pink color. Thirty ppm is generally accepted as the maximum amount of water permissible when fueling aircraft. The HYDROKIT® is designed for "fail-safe" operation, with false negative readings unlikely. Almost any error in performing the test will indicate the presence of wet fuel. If the sample indicates the presence of excessive water, it is always a good practice to repeat the test on a second sample.