Redox combination electrode for immersion sensors
• Only one housing for platinum and reference electrode
• Special double membrane for high signal stability
• For depths up to 6,000 m

The Problem:
Redox potential measurement systems, consisting of a noble metal electrode and a reference electrode, are useful for the numerical determination of the reduction or oxidation potential of water samples. However, problems can arise when measuring ORP in seawater if conventional reference electrodes with ceramic membranes are used, as high and variable junction potentials develop under high pressure. Therefore, redox potential measurement systems have previously only been offered for depths of up to 1,500 m.

In addition, using two channels of the probe system for pH measurement—one for the glass electrode and one for the reference electrode—proved to be somewhat cumbersome.

The Solution: A versatile combination electrode for underwater probe systems – also flexibly usable in standalone operation
The redox combination sensor consists of a reference electrode and a noble metal electrode in one housing. For accurate measurements in the deep sea, a special double membrane was used for the reference electrode to achieve better signal stability under pressure changes. The redox combination sensor for in-situ determination of redox potentials is available as a deep-sea version (up to 600 bar) without an integrated temperature sensor.