This publication is intended to provide shippers and carriers with a guideline method of analysis to determine the presence in anhydrous ammonia of the prescribed minimum water content of 0.2% by weight as required by DOT regulations. Lack of the appropriate percentage of water in single loads of ammonia has been found by experience to result in extensive stress corrosion damage to the QT cargo tanks. This method is intended for field use and thus the equipment and procedure selected may vary slightly from that used under laboratory conditions. Other proven methods of determining water content such as Orono Spectral Solution’s “Standard Test Method for Water in Anhydrous Ammonia (0.2 to 0.5%) by Infrared Determination (Version 2017 – 03.2), authorized by DOT Special Permit SP 20402, are acceptable.