Moisture Meter Literature?

[Art Davis]

Okay, so I did a search and opinions on moisture meters seemed all over the map. So-----does anyone have a recommendation for literature I could read on moisture meters that might give me some idea of the tradeoffs between pinned and pinnless types and relative costs?

Thanks.

Art

[Rob Will]

Art,
I don't have any literature in mind but here is a product video that you might want to see.

http://store.baileys-online.com/cgi-bin/baileys/5213?mv_session_id=SJkqqEzR&product_sku=17719

Rob

[Glenn Clabo]

Grab a cup of coffee....
First...I do this as a hobby so the final proof is cost and function...
After the below research I ended up buying this - When it was onsale for $76.00...and it has worked as advertised...
http://www.amazon.com/gp/product/B0000224D8/102-0131578-2193737


General comment -
"There are two types of moisture meters: conductance and dielectric. Conductance meters have two to four probes that are physically inserted into the material being tested. They read the moisture content of the material through the electric conductance detected between electrodes. Higher moisture levels facilitate better conductance, thus higher moisture readings. Dielectric-type moisture meters are non-invasive. They generate an electrical field through flat platens located on the bottom of the meter. These, in turn, analyze characteristics about the electric field to generate a moisture content reading."

Acedemic paper -
Methods of Moisture Content Measurement
in the Lumber and Furniture Industries
by Phil Mitchell Assistant Professor and Wood Products Extension Specialist North Carolina State University

http://www.ces.ncsu.edu/nreos/wood/wpn/methods_moisture.htm

"Comparing Resistance and Dielectric Meters
Both types of meters measure wood MC with the same accuracy over about the same moisture range. Although one type of meter is not clearly better than the other, one meter type might better meet your needs. Let’s compare some of the advantages and disadvantages of these two types of meters.
_ With pins that penetrate the lumber, resistance meters leave holes in the wood. Dielectric meters use surface contact electrodes that are non-invasive and leave no marks.
_ The use of insulated pins with resistance meters allows the measurement of lumber moisture gradients which is useful to kiln operators. Dielectric meters cannot provide gradient information but instead give the average MC of a slightly larger area. In addition, dielectric meters are more reliable on wood having a fairly uniform MC than on wood with substantial moisture gradients (early morning surface dew can cause reading errors).
_ Dielectric meters can read to slightly lower MC than resistance meters.
_ Resistance meters are not sensitive to differences in wood density. Although dielectric meters provide species corrections that are based on average species density, the MC readings are sensitive to within species variation in density.
_ Resistance meters typically are used with a separate hammer/electrode probe, making them more bulky to carry around on the factory floor. In addition, these electrodes require frequent attention due to broken or loose pins or broken cables, and can be sensitive to static electricity in dry, cold weather. Because the moisture sensing element is built into the case of the dielectric meter, it is more compact and easier to carry around the plant."


Forrest service report here...
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr06.pdf

A report from the land down under - which pointed me toward the conductive (pinned) type.
http://www.fwprdc.org.au/content/pdfs/moisture%20meters%20mr.pdf

More -
http://www.colostate.edu/programs/cowood/New_site/Publications/Articles/moisturemeter.pdf

[Art Davis]

Rob,

Had a look at the link you provided. It looks great, but "pricey" for a beginning woodworker. Maybe one of these days----.

Glenn,
You're right on the "grab a cup of coffee," but I think it will take more than one cup! Just what I was looking for. Thanks a bunch.

Art