CoverMaster
Victoria García Acero
CoverMaster (Elcometer 331) is a portable, convenient, accurate rebar locator and concrete covermeter that can be used in all types of reinforced concrete structures.
The instrument is based on the pulse-induction technique. A repetitive current pulse is applied to the coils in the search head whose magnetic field induces eddy currents in a bar located below the search head. The instrument measures the amplitude of the induced current, which depends on the orientation, depth and size of the bar.
To identify the location and orientation of the rebar under the surface of the concrete, a search head is connected to the covermeter and is used to scan across the designated search area. When the bar is positioned below the center of the search head, the signal strength will be at its maximum by which the instrument measures the depth of the position and estimates the diameter size. The technique is uniquely stable, is not affected by moisture in concrete or magnetic aggregates and is immune to temperature variations and electrical interference.
A range of fully interchangeable search heads are available to suit different requirements. Changing from one search head to another is quick and simple.
The CoverMaster (Elcometer 331) can also be used with half-cell electrode probes to measure half-cell potentials in accordance with ASTM C876, in a similar manner to the Mini Grate Dane (see its technical data sheet).
- Locate position and orientation of reinforcing bars and metal cable ducts in concrete structures
- Measure the cover depth of reinforcement
- Estimate the diameter of reinforcing bars
- Locate other metal objects embedded in concrete
- Condition surveys of suspect reinforced concrete structures to identify areas with corrosion activity by the half-cell potential technic (ASTM C876)
The CoverMaster (Elcometer 331) is available in different models. Consult the Technical Data Sheet for information about the corresponding features.
- 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
- Operation temperature: 0 to 50°C
- Rugged case IP65
The CoverMaster (Elcometer 331) is available in different models. Consult the Technical Data Sheet for information about the corresponding features.
All covermeters are delivered with your selected search head and/or half-cell electrode, including connecting cables, rechargeable battery pack and charger, earphone, shoulder strap, plastic carry case, operating instructions, CoverMaster™ software (for SH, TH & THD models) & PC cable (for SH, TH & THD models).
Search Heads | |
Standard General purpose Cover layer range: 15 to 95 mm for 40 mm bar 8 to 70 mm for 8 mm bar Sensing area: 120 x 60 mm |
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Narrow Pitch For resolving closely-spaced bars Cover layer range: 8 to 80 mm for 40 mm bar 5 to 60 mm for 8 mm bar Sensing area: 120 x 60 mm |
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Deep Cover For deep-located bars Cover layer range: 35 to 180 mm for 40 mm bar 25 to 160 mm for 8 mm bar Sensing area: 160 x 80 mm |
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Dual Search For high strength and stainless steel (only for model THD) Cover layer range: 35 to 180 mm for 40 mm bar 25 to 160 mm for 8 mm bar Sensing area: 160 x 80 mm |  |
Half-Cells Kit | |
Suitable for models BH, SH, TH and THD. Consists of either a copper / copper sulphate electrode or a silver / silver chloride electrode. Each half cell is a sealed unit, no need to mix chemicals. It is supplied with a 25 m cable. |
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Borehole probe | |
Borehole probes are also available for locating a second layer of reinforcement or deeply embedded tendon ducts. The borehole probe can be switched from the “forward looking” to the “side looking” mode. Measurement depth: Short probe = up to 400 mm / Long probe = up to 1000 mm |
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BS 1881-204:1988: Testing concrete Recommendations on the use of electromagnetic covermeters
BS1881-201: Testing Concrete – Part 201: Guide to the Use of Non-Destructive Methods of Test for Hardened Concrete
ASTM C876: Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete
