 
Concrete Permeability Tester
Designed by the BCA this equipment measures air permeability and reletive humidity of concrete cover on site
Introduction
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.
Description
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.
Specification
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
Stopwatch
Insertion tool
Salt solutions
All items enclosed in a purpose-made
carrying case, 515 x 375 x 125 mm.
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