M. C. Miller offers a variety of reference electrode designs in the IonX Series for applications involving permanent burial in soil electrolytes.

General features and specifications common to all designs

• Zero leakage of half-cell filling solution: electrodes do not leak any corrosive elements into the soil
• Zero contamination of electrode by electrolyte: electrode half-cell potential is not affected by electrolyte elements, such as chloride ions
• Both copper/copper sulfate and Ag/AgCl electrodes are available
• Copper/Copper Sulfate Electrode Potentials are in the range 316mV ? 10mV @ 25°C versus the Standard Hydrogen Electrode (SHE)
• The molarity of the KCl filling solution can be specified in the case of Ag/AgCl electrodes (half-cell potentials can be specified in the 200-270mV range @ 25°C versus SHE)
• Electrodes can be stored at temperatures down to -20°C

IonXDE Permanent Electrodes: Unique Specifications

• A Copper/Copper Sulfate electrode and an Ag/AgCl (3.5M KCl) electrode share a common electrolyte in an integrated electrode package (see schematic diagram for design details)
• Structure-to-soil voltages can be taken versus either the CSE or the Ag/AgCl electrode, or versus both electrode types
• The calibration of the CSE electrode can be checked in-situ by taking a potential difference reading versus the Ag/AgCl internal electrode (see MP Article # 2 for details)
• Design Lifetime: 40 years
• Electrical Contact Area (with soil): 16.5 square inches
• Overall length: 16 inches
• Max. Diameter: 3 inches
• Weight (not including wire): 2.7 lbs