Accessories For D.O. Probes

YSI standard 1-mil membranes are perfect for most applications. If you're measuring below 15C or at low DO levels, use the high-sensitivity 0.5-mil PTFE membranes. To measure very high DO levels or for longer term monitoring, use the 2-mil membranes in the YSI 5685 membrane kit. They're less affected by biofouling and reduce DO sensitivity.