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<DIV><FONT face=Arial size=2><EM>----- Original Message ----- </EM></FONT></DIV>
<DIV>
<DIV><FONT face=Arial size=2><EM>From: Jim I<BR></EM></FONT></DIV>
<DIV><BR><FONT face=Arial size=2><EM>> My meter has 2
issues:</EM></FONT></DIV>
<DIV><FONT face=Arial>SNIP</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Correct. There are no meters available that will
accurately directly measure MC of a piece of wood at low
MC.<BR> <BR><FONT size=2><EM>> The RH tables are useful way to gauge
EMC, and I have used them. But, how long it takes a sample to reach equilibrium
is an open question in all of the hot boxes I've seen.</EM></FONT></FONT></DIV>
<DIV><FONT face=Arial>SNIP</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Not true. Evaluating equilibrium is easy. When I place a
panel in my hot box for drying, I push a small nail into the panel at one edge
and place a pencil mark on the opposite edge where a line between the two would
be perpendiclar to grain and near the widest part of the panel - usually around
three feet. When I first place the panel in the box I measure the distance
between the nail and the opposite edge at the pencil mark. Turn on the heat and
monitor temp and RH. When you have the proper temp and RH for your desired MC
(according to the chart), measure your panel width. Measure it again at 12 hour
intervals. Within two or three days you will observe the panel width to
stabilize at the target temp and RH of the box. Most panels will shrink several
millimeters going from about 9 or 10% MC down to 6%. So it is real easy to
accurately observe when equilibrium has been achieved.<BR><BR><EM><FONT
size=2>> That brings another inaccuracy to mind. How do we measure the
RH in the box. My first unsuccessful attempts used digital meters. I quickly
found that by putting 3 meters in the box I could get 3 different (sometimes
significantly) different RH readings (hey that way I choose the one I like
best). Further when I pushed the temp up past 110 degrees my meters lost their
minds.<BR></FONT></EM></FONT></DIV>
<DIV><FONT face=Arial>Just buy a good gauge. I bought one for maybe $200 (I
forget exactly how much). It is calibrated at the factory and comes with
certification that it is within some very small amount of error and is certified
by some very impressive atmospheric/humidity/ weather/ whatever national
association. Bottom line - you might want to go beyond Radio Shack and get a
decent gauge - I'm quite sure it is more than accurate enough for our
purposes.</DIV></FONT><FONT face=Arial></FONT></DIV>
<DIV><FONT face=Arial>
<DIV><BR><EM><FONT size=2>> But my question here is very basic step 1
material. When people are talking about their board EMC during
construction whatever their construction choice, how are the EMC's being
quantified...accurately.<BR></FONT></EM></DIV>
<DIV>I believe my methods described above will provide an EMC characterization
more than accurate enough for our needs. If you have any more specific questions
on any of my procedures or equipment, I'm happy to share.</DIV>
<DIV> </DIV>
<DIV>Hope this helps.</DIV>
<DIV> </DIV>
<DIV>Terry Farrell</DIV></FONT></DIV></BODY></HTML>