Ronn W Posted August 9, 2016 Report Share Posted August 9, 2016 The answer to this may be self evident but I will ask anyway to be sure........If I want to measure the MC of a piece of rough sawn lumber before I buy it, I need to plane a small area it down to relatively smooth wood if I am using a pinless meter, right? Quote Link to comment Share on other sites More sharing options...
pkinneb Posted August 9, 2016 Report Share Posted August 9, 2016 hmm. Not sure but if they can read up to 3/4" deep not sure why that would be necessary. look forward to seeing others input Quote Link to comment Share on other sites More sharing options...
Guest Posted August 9, 2016 Report Share Posted August 9, 2016 I don't know exactly how pinless meters work. I don't think they directly measure the moisture. I think they use a sonor-like technology to measure the density of the object being metered. It then compares the density of the object being measured to known species densities to back into the MC%. At least that is how mine works. If that is the case, I think it would be more accurate to read on a smooth surface. Quote Link to comment Share on other sites More sharing options...
Isaac Posted August 9, 2016 Report Share Posted August 9, 2016 In my opinion, pinless meters are generally best used for qualitative rather than quantitative measurements. I think a reasonably smooth surface is a good idea, but I've not seen this specifically mentioned in the literature on mine, which is a Moisture Encounter Plus. They simply aren't that accurate to get a reliable numeric value. Instead, they are best for comparing pieces of lumber. ie. is this piece more or less moist than other pieces in the same space? Quote Link to comment Share on other sites More sharing options...
Chestnut Posted August 9, 2016 Report Share Posted August 9, 2016 If the surface is slightly rough like from a band saw my meter is about 1-2% lower then a flat area. If there area areas that are ridges or deep gouges from blades it can be a lot further off and i wouldn't trust the number. Also be careful your hand behind the board can have a larger effect on your reading from a pinless then the surface roughness. Isaac i think it depends on the pinless meter and the precision you are going after. Different wood density can throw off a pinless meter just as mineral deposits or other materials with electrical properties, could throw off a pin meter. A reading of 6% on a meter represents moisture content of 5.5% to 6.49%. Quote Link to comment Share on other sites More sharing options...
Isaac Posted August 9, 2016 Report Share Posted August 9, 2016 17 minutes ago, Chestnut said: If the surface is slightly rough like from a band saw my meter is about 1-2% lower then a flat area. If there area areas that are ridges or deep gouges from blades it can be a lot further off and i wouldn't trust the number. Also be careful your hand behind the board can have a larger effect on your reading from a pinless then the surface roughness. Isaac i think it depends on the pinless meter and the precision you are going after. Different wood density can throw off a pinless meter just as mineral deposits or other materials with electrical properties, could throw off a pin meter. A reading of 6% on a meter represents moisture content of 5.5% to 6.49%. Those are good points, it is certainly true that the reading inherently covers a range. The literature I've read indicate a couple points. First, moisture meters lose accuracy at the extreme ends of high and low moisture, and second, pin meters are roughly twice as accurate as pinless meters, which is why I say that pinless meters are primarily useful for qualitative rather than quantitative use. That doesn't mean they are bad tools though. I actually use one in my non-woodworking professional work routinely. Quote Link to comment Share on other sites More sharing options...
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