4
BEFORE YOU BEGIN
The BD-10 features two scales
— one marked “wood” and the other marked “reference”. The wood scale
is used when testing
wood and the reading indicates the percentage moisture content.
The reference scale
reads from 0-100 and is used when testing any building material such as plaster, concrete, brick,
insulation, etc. Readings on the reference scale
are to be taken as a qualitative indication of the moisture level. Readings in the
low end of the scale indicate a “drier” condition; readings in the upper end of the scale indicate a higher moisture level in the
material. The scale is colour coded with green, yellow, and red areas. Readings may be interpreted as green (dry), yellow
(borderline), red (wet).
When using the reference scale
tests should be made on material samples that are known to be dry. Such readings can be
used as standards or reference points against which subsequent readings should be compared.
CHECK CALIBRATION
Press the calibration check button
. Meter is in calibration if the needle pointer m
oves to “20” on the wood scale
.
Any reading within the green band on the dial is acceptable. Make sure the contact pins
are not in contact with
anything when checking the calibration.
If you check the calibration and the needle does not read within the green band, it is likely an indication of a low battery. If this
occurs, change the battery (9-Volt) immediately. Continued use with a low battery may cause the meter to go out of calibration. If
you have a fresh battery and the instrument still does not indicate a proper calibration, return it to
Delmhorst Europe Testnology
for service. See
Service for Your
Meter
section for details.
TAKING A READING
Remove the protective cover
to expose the pins. Check that the contact pins
are firmly hand tightened.
USING 6-40% WOOD SCALE
Align contact pins
parallel to the grain pushing to their full penetration, if possible.
Press the read button
and read the moisture content on the wood meter scale
.
Delmhorst uses the USDA standard
–Douglas Fir–as the basis for all calibrations. Because the electrical characteristics of different
species vary, some species may read differently at the same moisture content. However, in most cases, the Douglas Fir reading
can be taken at face value on constructiongrade lumber. If you choose to apply species corrections please contact us at
Paint Failure and Moisture
Moisture is by far the most frequent cause of paint failure. The key to preventing paint failure is to make certain that moisture is not
absorbed through the wood to the back of the paint film. So, in order to insure quality paint jobs, wood must remain dry after the
application of paint.
Outdoor wood can be safely painted without danger of peeling if the %MC is 15% or less. In drier climates, the maximum reading
should be 10% to 11%. Indoor wood should be
between 7% to 8% prior to painting.
The following conditions may cause high moisture content in wood:
Leaky gutters and down spouts
Leaky pipes or condensation on cold water lines in attic or hollow walls
Faulty flashing around windows, doors and where porch and dormer roofs meet sidings
End-grain wood that is not sealed with paint at all joints around windows, corners, and butt joints
Porch columns that do not have good drainage and ventilation where they rest on porch floors
Siding or any other wood that is in contact with the ground
Siding and shingles without sufficient lap so that water is forced up through cracks by wind pressure
Ice dams
Condensation of vapor within hollow walls
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