OVERVIEW

The Omniterm TWC half-cell two-wire transmitter is designed for continuous monitoring of half-cells in cathodic protection systems.

The Omniterm TWC has high input isolation and ultra-high input impedance to ensure that half-cells will not be consumed with continuous monitoring.

The TWT module draws its power from the 4-20mA output loop, allowing the transmitter to be mounted close to the half-cell for most accurate measurement.

Full input isolation to 2500Vac ensures trouble-free accurate measurement in the most demanding applications.

Using advanced sigma-Delta A/D technology combined with sophisticated digital filtering techniques, the TWC offers 16 bit measurement resolution with increased dynamic range, tailored for harsh environments.

Combined with the free Omniset configuration software package, this product provides extremely low life-cycle costs by reducing spares stock-holding requirements, and reducing specialist technical expertise required for field support, on site module replacement and field configuration. This new holistic approach to instrumentation asset management ensures reliable performance and minimal down-time.

PRINCIPLES OF CATHODIC PROTECTION

Cathodic Protection is a technique commonly used to prevent corrosion in metallic structures. The principle of cathodic protection is in connecting an external anode to the metal to be protected and the passing of an electrical dc current so that all areas of the metal surface become cathodic and therefore do not corrode.

The external anode may be a galvanic anode, where the current is a result of the potential difference between the two metals, or it may be an impressed current anode, where the current is impressed from an external dc power source.

Structures commonly protected are the exterior surfaces of pipelines, jetties, foundation piling, steel sheet-piling, offshore platforms and concrete steel reinforcing.

Cathodic-protection systems may be monitored effectively by the measurement of structure-to-electrolyte potentials, using a high input impedance voltmeter and suitable half-cell. The standard practical half-cells are copper/copper sulphate, silver/silver chloride/seawater, silver/silver chloride/ potassium chloride and zinc.

Adjustments are made to the cathodic-protection current output to ensure that protective potentials are maintained at a sufficiently negative level.

The Omniterm TWC Module is tailored for performing these half-cell measurements in permanent installations

PART OF THE FULL RANGE

The Omniterm TWC is part of the latest Omniterm range of signal conditioning modules.
See the full Omniterm range here

Contact Omniflex, and try one. You will never see signal conditioning the same again.