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Permeability Tester for Concrete

Concrete Permeability Tester

Designed by the BCA this equipment measures air permeability and reletive humidity of concrete cover on site


Designed by the BCA, This equipment measures air permeability and relative humidity of cover concrete on site. A blind hole drilled or formed in the concrete is sealed with a special plug, and the resulting cavity pressurized with air. The permeability of the concrete is calculated from the time taken for the pressure to drop. If the capillary pores are partially blocked with moisture, the permeability is reduced. Therefore the relative humidity of the cavity is also measured.

A blind hole 20 mm diameter by 35mm deep is cast, drilled or cut in the concrete with a diamond-tipped coring tool.
A stainless steel insert is located into the hole and sealed, leaving a measurement cavity of known volume.

The relative humidity of the cavity is measured by inserting a capacitive probe through the insert and taking its reading after one minute. The probe is then removed.

A pressure manifold, fitted with a pressure transducer and a Schraeder valve, is attached to- the insert, and pressurized using an automobile-type foot pump.

The output from the pressure transducer is monitored on a battery- operated digital meter, and the time taken for the pressure to decay is monitored using a stopwatch. Saturated salt solutions are provided for correcting the relative humidity value measured in the cavity.

Pressure sensor -2 bar silicon diaphragm
Pressure meter- battery-operated, direct- reading LCD display
Humidity meter - Vaisala relative humidity temperature meter with retractable probe

Stainless steel pressure manifold and inserts
Insertion tool
Salt solutions
All items enclosed in a purpose-made carrying case, 515 x 375 x 125 mm.