Mettler Toledo InPro6820/12/220 Dissolved Oxygen Sensor

The Mettler Toledo InPro 6800 Dissolved Oxygen Sensor (Catalog 52201013) is the industry-standard polarographic (Clark-style) probe designed for hygienic, sterile bioprocessing applications. With a 12 mm diameter and a 220 mm insertion length, this sensor is specifically dimensioned for top-entry installation in mid-sized benchtop bioreactors (typically 3 to 7 Liters), such as those from Applikon, Eppendorf, or Sartorius. It is constructed from FDA-compliant 316L Stainless Steel with a high-quality surface finish (N5/Ra 0.4 µm) to facilitate easy cleaning and prevent biofilm adhesion.

Technically, this model (often referred to within the 6800/6820 series) features the robust VarioPin (VP) connector. Unlike older threaded connectors, the VP system is watertight (IP68 rated) and ensures a stable signal even in humid environments or if the connection gets splashed during harvest. The sensor is fully capable of withstanding Steam-In-Place (SIP) and repeated autoclaving cycles up to 140°C. It utilizes a modular, replaceable membrane body concept, allowing users to swap out the sensing element (the membrane and electrolyte) in seconds rather than replacing the whole probe when fouling occurs.