YSI 2003B [607203] Polarographic Dissolved Oxygen Sensor. The YSI 2003B polarographic dissolved oxygen sensor provides reliable DO readings and includes the 5909 blue 2.00 mil PE membrane kit. The YSI 2003B is designed for use with the Pro20, Pro20i, Pro1020, Pro2030, and Pro Plus instruments; cables must be ordered separately. It can be used on 60520 (DO), 6052030 (DO/conductivity), 6051020 (DO/ISE), and 605790 Quatro (DO/conductivity/ISE/ISE) cables. The YSI 2003B comes with six membrane caps and bottle of solution.