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Moisture Meter Not Accurate???

Discussion in 'The Wood Pile' started by 94BULLITT, Dec 20, 2015.

  1. 94BULLITT

    94BULLITT

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    How can I tell if my moisture meter is working properly? I know HDRock said to stick in the palm of your and it should be around 35%, which mine is. I even checked it against another one exactly like it and they were very close. I still don't trust it. I split some wood yesterday and the meter says it is way dryer than what I think. Also wood won't burn good in my stove unless the meter says 12-15%. The stove manufacturer says anything under 20% is dry. I also thought that 12% was next to impossible to get by air drying. The meter I have is the general tools from Lowes. When I use it I split a piece open and stick the meter tips of the meter deep in the middle of the split.
     
  2. oldspark

    oldspark

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    I tried my MM in every type of wood I could find, what I knew was wet and dry, different sizes of construction lumber and it all came out good to the point I trust mine.
     
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  3. jtaves85mcss

    jtaves85mcss

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    Are multiple reading results consistent/repeatable on the same split? Are you testing with wood that is 70*F? If so, I would say your meter is reliable.
     
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  4. haveissues

    haveissues

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    Try it on something freshly cut and see if you get a plausible reading.
     
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  5. Jon1270

    Jon1270

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    Keep in mind that when there's liquid moisture present, which in wood means anywhere over about 28%, common electronic moisture meters are wildly inaccurate. A reading of 35% should be interpreted as meaning nothing more specific than "this material is wet."

    Also, the presumption in meter design is that the wood is at 70 degrees Fahrenheit. If you are checking cold splits off of an outdoor woodpile, the readings will err to the low side.
     
  6. bocefus78

    bocefus78

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    Split a 2x4 and test it.
     
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  7. Paul bunion

    Paul bunion

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    A MM is nothing more than an ohm meter, you can test it with a resistor. My meter came with a test resistor built into the cap. It is 1M ohm and it reads 27%. Depending on the pin spread and calibration, meters will read different. The chart on page 6 of this document http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr06.pdf shows values.
     
  8. bobdog2o02

    bobdog2o02

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    This is spot on,

    94BULLITT I have gotten oak down to 13% in 3 years, carefully storage and small splits were my ticket. It all has to do with the climate in your area. In VA you can get pretty low. In the Pacific Northwest you should expect different redults.
     
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  9. 94BULLITT

    94BULLITT

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    Thanks for all the replies. Yes, it is consistent. I did not know that wood needed to be at 70* for it to be accurate. The owners manual does not mention that:headbang: I tested a piece of lumber in the past but I forget what it was.

    Paul bunion Thanks, for the link. There is a lot of good info there. It looks like if my meter is calibrated to 70* I need to add 1% for every 20* that the wood is below 70*. I may try testing a split with an ohm meter.

    bobdog2o02 Maybe my wood storage method is better than I thought.
     
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  10. Sean

    Sean

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    Check out how dry this was. This was a standing dead dropped mid to late September. Ive even had some pine that wouldnt register on my meter. Im glad to see so many people mention the 70 degree rule as this is very important. If Im wondering about the mc during the winter I will bring a split inside overnight and then split it and test it.
    IMG_4867.JPG IMG_4869.JPG
     
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  11. bobdog2o02

    bobdog2o02

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    FWIW, i dont call it valid unless pushing while the meter reads. i think its mostly the hardwood i have, if i let up the number goes down.... im a glass half wet kind of guy with this.
     
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  12. Sean

    Sean

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    I agree with that especially on harder wood. With this being so soft the prongs bury in and dont let go.
     
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  13. 94BULLITT

    94BULLITT

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    I checked my MM against an ohm meter and it looks like my MM is with in 10%.