In loving memory of Kenis D. Keathley 6/4/81 - 3/27/22 Loving father, husband, brother, friend and firewood hoarder Rest in peace, Dexterday

An Experiment... checking my MM's accuracy

Discussion in 'The Wood Pile' started by bobdog2o02, Jan 3, 2016.

  1. bobdog2o02

    bobdog2o02

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    So i cut two BIG hunks of Hackberry with the saw in the end of november. They each just barely fit through the loading door on a BK princess. When i cut them i probed them with the MM(Moisture Meter). For my experiment im going to track the weight about once a month unitl i burn them, i plan on burning them once the weight change flattens out. I have been storing them about 4 ' to the side of the stove along the block wall, which is also where I keep the stash near the stove, about a face cord at a time. So here is my math for one of these pieces, let me know if im on the right track. Also, i realize ALL of the math below
    is assuming that my MM gave an accurate reading intially.
    ----------------------------------------------------------------

    MATH EDITED 1/3/16 4:23PM EST



    Nov. 28, 2015

    Weight - 29LB
    %MC - 30% per MM

    29lb / 130 = .2230 Pts of total

    100%(wood value) * .2230 Pts = 22.3Lbs wood


    ----------------------------------------------------------------

    Jan. 3, 2016

    Weight 25.5 LB

    3.5lbs water lost *.2230Pts % = 15.69%pts lost

    30% MC original - 15.69% lost = 14.31% MC left in wood.


    20160103_113423.jpg
     
    Last edited: Jan 3, 2016
  2. bobdog2o02

    bobdog2o02

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    More pics, or it didnt happen right...
     

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  3. bobdog2o02

    bobdog2o02

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    I guess i forgot to mention what makes it an experiment. I'm going to split one and recheck with the MM just before burning to see if my projected MC is close to what the MM tells me it is....
     
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  4. Paul bunion

    Paul bunion

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    You are on the right track but your calculations are a little wrong. The way you did it is on a wet basis. Moisture meters read on a dry basis. Dry basis is expressing the weight of the water compared to the weight of the wood if it had no water in it. Wet basis is a simple ratio as you worked it out to be.

    To think on a dry basis it is much easier to understand if you think in terms of parts and not pct. You will always have 100 parts of wood and the moisture meter reads the number of parts water that there is. So 30% you have 30 parts water and 100 parts wood. Or 130 parts total. So divide your original weight 29 lb by 130 to figure out what a single part (or pct point is). 29 lb/130=.223 lb. Round it up to .25, each point of moisture is going to roughly weigh a quarter pound.

    The wood itself with no water weighs 100 x .223 or 22.3 pounds. That never changes and will be a light as you can make it providing your original reading was correct.

    So your loss so far, 3.5 pounds will amount to 3.5/.223 = 15.69 points. (The actual water loss is in fact quite interesting). Your starting measurement was 30%, You are now at 30-15.7=14.3% or you have 100 parts wood and 14.3 parts water. And those calculations are all relying on the original measurement being accurate across the piece of wood.

    Make sense?
     
  5. bobdog2o02

    bobdog2o02

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    Makes perfect sense. I didn't know the wet/dry basis stuff. With this knowledge i'm going to go to weekly measurements. I'm going to edit the post above and then edit the notes when I do, I'll keep following up with data as I go.
     
    Last edited: Jan 3, 2016
  6. bobdog2o02

    bobdog2o02

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    Fyi, these pieces are what I plan on using for the time lapse video I've mentioned. I realized my action cam will die long before the stove quits so I'll have to borrow a camera from my SIL.
     
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  7. milleo

    milleo

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    :popcorn:
     
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  8. bobdog2o02

    bobdog2o02

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    Paul bunion can you look at the original post again, i edited . let me know if i expressed everything correctly.
     
    Last edited: Jan 3, 2016
  9. CTYank

    CTYank

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    What I've found to help to track the air-drying process of some splits, besides jamming the MM's electrodes into exposed faces, is to also jam them into/througn the bark, to get some high readings. Once the latter drop, things are looking good for that wood and the batch of which it's a sample.
     
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  10. Paul bunion

    Paul bunion

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    Yes, looks like you got it.
     
  11. papadave

    papadave

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    :popcorn:
    Even though milleo beat me to it.
    I like these experiments, especially when BKs are involved.:thumbs:
     
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  12. milleo

    milleo

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    I was hungry and couldn't wait papadave
     
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  13. papadave

    papadave

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    No problem, I always share popcorn.:thumbs:
    Still,:popcorn:
     
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  14. Locust Post

    Locust Post

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    Bogy Dave had some of these experiments going last year or maybe the year before.
     
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  15. bobdog2o02

    bobdog2o02

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    I'd love to look at those threads if anybody can throw up a link. digging for stuff that old can be a pain in the butt. bogydave
     
  16. bobdog2o02

    bobdog2o02

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    Updated data from the weekend, calcs to follow

    [​IMG]
    [​IMG]
     
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  17. papadave

    papadave

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    Gained almost 1/2 lb on the 2nd, smaller piece, or am I seeing the numbers wrong?
     
  18. bobdog2o02

    bobdog2o02

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    It's a 4. I know it looks like a 9, hard to wrote on the wood worth the saw grooves
     
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  19. papadave

    papadave

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    Ok, so it still lost a little bit in the last week.
    Are they off the concrete floor? This is interesting stuff.
     
  20. bobdog2o02

    bobdog2o02

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    Nope, sitting on the concrete 3ft from the dark box.