Robust and waterproof for field applications Optical, low maintenance dissolved oxygen measurement Adjustable t90 for direct monitoring of online systems The Oxi 3310 IDS is handy dissolved oxygen measurement at its best: compact and space-saving, reliable, easy-to-use with menu controlled user interface. In combination with the universal optical D.O. sensor FDO® 925 many applications can be covered from surface and ground water applications, monitoring of online systems and many more.With an Oxi 3310 IDS the FDO® 925 has an increased resolution of 0.001 mg/l below the range of 1 mg/l.