Cover Meter Operation Procedure

A concrete cover meter is used to measure with the most precision possible the distance between the top of a reinforcing steel bar (rebar) and the concrete surface. Cover meters use electromagnetic or ferromagnetic energy to locate bars and measure depth, and are typically sensitive to all metal in the influence region of their probe.

Accuracy as good ± 1mm at a 40 mm depth may be obtained by following a clear operating procedure, the purpose of which is to limit any interference, correctly configure the cover meter's settings and isolate a single bar beneath the probe with correct alignment.

The Profometer PM8000 cover meter has replaced the Profoscope Cover Meter and all previous Profometer models. This cover meter still used Pulsed Eddy current to measure concrete cover in beams, slabs, columns and other concrete elements.

Procedure

1. Review documentation for cover layout, where available.
   1. Setting the known Bar Diameter in a concrete cover meter will ensure the most precise cover depth. If there is no documentation consider exposing a bar to measure.
   2. Bar Spacing may be used to set the PM8000's Neighbouring Rebar Correction (NRC) functions, needed for the best depth measurement when bars are closer than 130 mm to each other.
   3. Congested, lapped or doubled rebar will interfere with measurement. Ideally the operator will avoid these location, or adjust the cover meter settings to read accuralty.
2. Use the cover meter to locate bars in longitudinal and lateral directions.
   1. Sketching the grid layout of bars onto the concrete surface will reveal the clearest line to measure accurate cover depths
   2. The critical measurement is the cover to the bar closest to the surface. When measuring individual bars or using the PM8000's Area Scan function this allows the operator to measure only to these bars
3. Measure bar depth with the cover meter
   1. The PM8000 Lite can collect a list of bar depth and diameter estimates, PM8000 can produce a Line Scan as well showing all bars in one pass and the PM8000 can produce an Area Scan of shallowest cover vs region or a 3D Area Scan of bars in each direction.
   2. The lowest cover is recorded when the cover meter is placed directly on top of a reinforcing bar, aligned along its length and as far away from perpendicular bars as possible.

Webinars

Presented by William Ward, webinar videos highlight the correct operating procedure for all cover meters, and the specific details of using the PM8000 Lite, PM8000 and PM8000 Pro model's features.  The videos also look at the PM iPad OS application, operation of the Profometer without a cart and more.

Video 1 - The new PM8000 Cover Meter

Video 2 - Rebar Locator and Cover Meter Operation

The second webinar revisits cover meter operation and now includes instruction for the new features introduced into the PM8000 rebar cover meter, including Area Scan Mode, Signal strength indication in the PM8000 Lite and when using other PM8000 models without the wheeled scan cart.