Copyright
2011, Delmhorst Instrument Co.
Page 11 of 17
Taking a surface reading:
USING PIN MODE
Ø
Drive two hardened-steel masonry nails
about 3/4" apart
into the finish coat of
concrete floor. Drive them about 1/8" deep so they make firm contact with the concrete
and do not move when touched.
Ø
Touch the nails
with the contact pins. Remember that when used on materials other
than wood, the meter’s
PIN
mode will give relative readings only. Establish a baseline
reading by taking a reading in an area you know to be unaffected, then take a reading in
the affected area and compare the two readings.
USING SCAN MODE
Ø
First establish a benchmark. Take readings in areas that you know are dry, or
acceptable.
Ø
Take readings on areas that are wet. These “dry to wet” readings can be used as
reference points against which subsequent readings are compared. Understanding the
meter’s behavior on a particular material, along with these comparative readings, your
experience, and visual clues will all help determine the overall condition. All readings
should be evaluated in the light of factors such as type of paint, type of construction, and
climatic conditions.
Subsurface test:
Ø
Drill two 1/4" holes,
3/4" apart and 1/2" to 2" deep.
Ø
Drive the masonry nails
into the bottom of the holes and make the tests as described
above. Nails must not touch sides of drilled holes.
If the meter still indicates a “dry” condition, the floor is ready for covering. Tests should be
made at several points, especially when the slab is thick (4” or more) and air circulation is
poor. Make tests only in newly drilled holes.
When evaluating a slab for readiness, always consider its age, thickness, whether the
slab is on grade or suspended, whether a vapor barrier is present and the drainage
condition of the ground. These characteristics can influence the normal or acceptable
moisture reading obtained by this measurement. A control measurement in an
unaffected area should be obtained to assist in establishing an appropriate target.
TESTING INSULATION:
To take a reading,
attach a 21-E electrode with 4” insulated contact pins to the meter. Push the
contact pins through the Drywall into the insulation behind it. Remember that when used on
materials other than wood, the meter’s
PIN
mode will give relative readings only. Establish a
baseline reading by taking a reading in an area you know to be unaffected, then take a reading in
the affected area and compare the two readings.