Delmhorst Instrument TotalCheck User Manual
Page 24
Copyright
2006, Delmhorst Instrument Co.
Page 24 of 32
Set the meter’s parameters as described previously in the owners’ manual. If the
species (construction-grade only) is unknown, set the meter to the reference
calibration, Douglas Fir and take the readings at face value.
To take a reading, align the contact pins parallel to the grain and push them to their
full penetration into the wood, if possible. Insulated pins read only at the tip and can
be driven to the desired depth.
Press the SELECT button and read the moisture content on the meter scale. The
meter displays the %MC for two seconds.
To add a reading to the previously stored readings, release the SELECT button if
you are in triggered mode. If you are in continuous mode, the meter will not store a
new reading until the SELECT button is pressed and released again during the
reading cycle.
NOTE: MC RANGE AND VALID READINGS
Readings below 5% or above 60% are displayed as LOW or HIGH, respectively.
However, since the resistance of the wood also depends on the species and
temperature of the wood, the meter may not always be able to read down to 5%. For
different species and different wood temperatures, there is a minimum %MC limit below
that the meter can not read. All readings below this “lowest limit” are displayed as LOW,
and are not stored. These readings are not considered valid readings and are not used
by the meter in any statistical calculations.
PAINT FAILURE AND MOISTURE
Moisture is by far the most frequent cause of paint failure. The key to preventing paint
failure is to insure 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