The CoverMaster (Elcometer 331) is a portable and precise instrument designed for locating rebar and measuring concrete cover in reinforced structures. Utilising pulse-induction technology, it ensures accuracy and convenience for a wide range of applications. A current pulse is applied to coils in the search head, creating a magnetic field that induces eddy currents in rebar. By measuring the amplitude of these currents, the device determines the rebar's orientation, depth and size.
Key Features
- Rebar Detection: The search head scans the concrete surface to locate the exact position and orientation of rebar. When the bar is directly under the search head, the signal peaks, allowing the device to measure depth and estimate the diameter.
- Highly Stable Measurements: The CoverMaster's technique remains unaffected by moisture, magnetic aggregates, temperature fluctuations, or electrical interference.
- Interchangeable Search Heads: A variety of easily interchangeable search heads are available, allowing flexibility to meet different project needs.
- Half-Cell Potential Measurement: The CoverMaster can be used with half-cell electrode probes to measure corrosion potential according to ASTM C876, making it a valuable tool for condition surveys of reinforced concrete structures.
Applications
- Locate reinforcing bars and metal cable ducts in concrete.
- Measure the concrete cover depth over reinforcement.
- Estimate rebar diameter.
- Identify metal objects embedded in concrete.
- Conduct condition surveys for corrosion activity using half-cell potential methods (ASTM C876).
Specifications
- Power Supply: 7.4V battery pack.
- Battery Life: 32 hours of continuous use (20 hours with backlight).
- Recharging Time: 4 hours.
- Dimensions: 230 x 130 x 125 mm.
- Weight: 1.6 kg (without accessories).
- Half-Cell Measurements: -999 mV to +999 mV, ±5 mV.
- Operating Temperature: 0 to 50°C.
- Rugged Case: IP65 rated.
Standards
- BS 1881-204:1988 – Recommendations for using electromagnetic covermeters.
- BS 1881-201 – Guide to Non-Destructive Methods for Hardened Concrete.
- ASTM C876 – Corrosion Potentials of Uncoated Reinforcing Steel in Concrete.