Manganese Dioxide

Manganese Dioxide Reference Electrode

50+ year design lifeSolid-state construction with no internal gel or electrolyte. Independently tested for long-term stability in reinforced concrete — design life exceeds 50 years under normal service conditions.Ideal for marine environmentsManganese dioxide chemistry is stable in chloride-rich environments. Suitable for tidal zones, splash zones, and permanently submerged marine concrete structures.ISO 12696:2022Meets the requirements of the international standard for cathodic protection of steel in concrete, covering electrode performance, calibration procedures, and documentation requirements.
ModelRB15

About the RB15

The Castle RB15 Reference Electrode comprises a manganese oxide core containing an alkaline environment. This is contained in a blue nylatron casing with a cementitious mortar cap. The electrode is conditioned to provide a very stable reference electrical potential. The mortar cap ensures good contact with the parent concrete.

Castle RB15 manganese dioxide reference electrodes are connected to a data logger to monitor readings which may be manually downloaded or transmitted remotely via modem to an external office. Measurements may also be performed by use of a handheld volt meter with high input impedance (>100 MΩ).

The RB15 reference electrode functions as a solid state electrode (no internal gels) and does not require aggressive materials, for example chloride ions, to function. It can be used in most environmental conditions. The side holes in the monitoring tip ensure good contact with the concrete.

Technical specifications

Dimensions75mm long × 16mm diameter
PotentialNominally +170mV ±20mV wrt SCE at 20°C
Drift<3mV in 24 hours; typically less than ±10mV expected over 20 years
Cable
optional
2.5mm² XLPE/XLPE or XLPE/PVC, blue/blue
Design life50+ years
Shelf lifeNominally 12 months
StorageDry and at constant temperature (5°–45°C)
CalibrationEach electrode calibrated before delivery; calibration certificate issued

Why us

30 years of proven performance

Trading since 1994

Over 30 years manufacturing reference electrodes. Our earliest installations — supplied in 1994 and 1995 — are still performing in harsh environments today.

Calibrated & certified

Every electrode is individually checked against a master reference and supplied with a calibration certificate traceable to ISO 12696:2022.

Made to order

Manufactured to your specified cable lengths, sizes and configuration. We advise on specification and get back to you within 24 hours.

Shipped worldwide

Supplied to infrastructure projects in 45+ countries — from UK motorways to the Burj Khalifa. Exported from the UK via DHL courier.

Speak to a specialist

Tell us about your project — structure type, environment and electrode count. We'll recommend the right specification and provide a quote within 24 hours.