The polarographic (Clark cell) dissolved oxygen (DO) sensor performs best in clean water. In environments with high organic content, the membrane can become fouled. Rips, tears and other damage will also affect membrane performance. For best results, replace the membrane when the slope and offset calculated during calibration change dramatically, and also after a long-term deployment.

The DO service kit contains:

• Membrane modules (5)
• O-rings (10) and o-ring lubricant
• DO electrode filling solution (potassium chloride, KCl)
• Ammonia cleaning solution and brush
• Polishing strips