Applicable to the analysis of potable waters, ground waters, and lightly polluted surface and sea waters. Determines filterable and acid-soluble aluminium. Includes low range determination up to 100 µg/l Al with 50 mm cells and high range determination up to 500 µg/l Al with 10 mm cells. The limit of detection is 2 µg/l when cells of optical path length 50 mm and a 25 ml test portion are used.