MN15 Reference Electrode
A common method of assessing the corrosion state of reinforcing steel is to measure the steel potential using a reference electrode.
CPT manufacture a reference electrode, MN15, which is buried in a small hole formed in the concrete surface. This can then be used to measure the steel potential either manually, using a high impedance voltmeter, using a datalogger or remotely using a cellular phone link.
The MN15 reference electrode offers significant advantages versus conventional electrodes as it is based on a manganese oxide composition:
- High surface area prevents loss of contact with host concrete
- Chloride free – no release of aggressive salts
- Excellent polarisation characteristics – stable potential when current is drawn
- Compact unit facilitates simple installation
Long Term Performance Data
CPTs MN15 reference electrodes were installed into the supporting piers at Whiteadder Bridge in Northumberland and were connected to CPT’s automatic data logging boxes. Installing telecommunication modems have allowed the live data from the monitoring boxes to be accurately relayed back to both the client and CPTs offices simultaneously over a period of nearly10 years. This has had the advantageous effect of drastically reducing the number of visits required to the site to gather information – especially useful in remote areas. Whiteadder Bridge is just one of many structures that have been monitored long term by CPT to both record system performance and assess real-time structural condition of the reinforcing steel.