Moisture Meter

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

sixman

Feeling the Heat
Apr 12, 2010
257
Central Texas
New to wood burning this year and thought that I might buy a meter to see how my wood is drying till I can get an idea of how long it needs to cure. Burning mostly mesquite and post oak and figure both will pretty much dry in one year here in Texas with these hot 100 degree days and low humidity. I would just like to check it the first couple of years till I get the hang of it. Where is a good place to get one at a reasonable price and how do you use them? Do you have to cut the wood in half and measure in the middle?
 
I bought that one just to play with and so far I agree with all the readings it has given me, some guy broke off one of the prongs but Ihave had no problems, I think it was well worth it.
 
How do you use it on the wood? Do you have to make a fresh cut?
 
Yes. Pick a round or large split, and re-split it, then stab it with the probes of the meter along the grain in the center of one face of a freshly exposed surface. Measuring on the outside or the end of a piece of wood won't tell you anything other than the fact that wood seasons from the outside in. Rick
 
Yes fresh cut or split and kinda average it with the out side reading.
 
Thanks, I just want to get a ball park figure to see if it is close, don't want to dirty up my new chimney. What is a good number to consider it ready to burn? I want to keep my new chimney clean.
 
Around 20% m.c. is considered ideal. I wouldn't worry much about a couple % one way or the other, and I actually wouldn't worry at all about readings below 20%. Dunno what sparky's referring to about "averaging"...in my mind, it's the freshly exposed inside center reading that's germane...everything else is gonna be less than that anyway, and I think that a reading on the outside or the end is pretty much meaningless for assessing the readiness of the wood for burning. Say I read 30% in the freshly split center, but 12% on the outside...is that wood good to burn because I can "average" it out to ~ 21%? I don't think so...that wood needs more seasoning. Get your wood to where you can open up a freshly cut split and read about 20% in the center, you should be good to go. Rick
 
Thanks for all the help!
 
Here is a piece of ash .edited out the pos.misinformation about the ash split.
 

Attachments

  • 1202091617.jpg
    1202091617.jpg
    30.9 KB · Views: 458
I was just thinking that with our climate here in central Texas, the oak and mesquite would dry in one summer but I want to check it to be sure.
 
fossil said:
Around 20% m.c. is considered ideal. I wouldn't worry much about a couple % one way or the other, and I actually wouldn't worry at all about readings below 20%. Dunno what sparky's referring to about "averaging"...in my mind, it's the freshly exposed inside center reading that's germane...everything else is gonna be less than that anyway, and I think that a reading on the outside or the end is pretty much meaningless for assessing the readiness of the wood for burning. Say I read 30% in the freshly split center, but 12% on the outside...is that wood good to burn because I can "average" it out to ~ 21%? I don't think so...that wood needs more seasoning. Get your wood to where you can open up a freshly cut split and read about 20% in the center, you should be good to go. Rick
Yes I know the wood need to be 20% or so to be good to go but if you are burning wood before it is ready you could average it some what, for the most part is is always going tobe a little more dry on the out side than in the middle until the wood gets much older. I have some 3 year old oak that I might check out to see if there is any difference between the out side and inside. Did not mean to imply that "averaging" was SOP.
 
I have that MM and works fine for me. It is nice to have something to go one when you are new to this stuff. After you get ahead, not a big deal, but still nice to check once in awhile. Especially Oak since it can take a long time.
 
17% mc after 2 months on that ash!! Was it live or dead when cut? I surprised it's that low...the ash I'm currently cutting is 39% green.
 
muncybob said:
17% mc after 2 months on that ash!! Was it live or dead when cut? I surprised it's that low...the ash I'm currently cutting is 39% green.
I'm thinking that is not a fresh split or the wood had been dead for a long time.
 
oldspark said:
Did not mean to imply that "averaging" was SOP.

It probably is, though. IMO, an average MC of 20% throughout the split is probably pretty close to as good as it gets for most folks.
 
Don't get to caught up in the readings. When I first bought my stove I had to have a moisture meter. Used it once and got readings over the 20%......freaked me out a bit. I burned the wood that winter making sure to keep good hot fires that got up to temp as quickly as possible. I had very little buildup in my stove pipe that spring.
 
I think a little over the 20% is no big deal, I think I read some where that the build up in chimney starts with upper 20's moisture(assuming evey thing else is OK), prime burning efficenty wise is 20% or so but a little higher is doable with out a problem.
 
Battenkiller said:
oldspark said:
Did not mean to imply that "averaging" was SOP.

It probably is, though. IMO, an average MC of 20% throughout the split is probably pretty close to as good as it gets for most folks.
The more I think about it it probably is an average of the piece more or less. I suppose if your wood is as old as Backwoods supply its dry to the bone. :lol:
 
muncybob said:
17% mc after 2 months on that ash!! Was it live or dead when cut? I surprised it's that low...the ash I'm currently cutting is 39% green.
.

Late fall, A tree service was taking down a neighbors ash trees and knocked on my door and asked me if I wanted it. I said sure and within minutes a constant parade of wheelbarrows full of logs went in my backyard. To be honest, Don't have a clue. It looked winter dead to me but. I thought it was alive b/c those trees had leaves on it in the summer. When I cut some of the rounds(b/c log length was 22-24") It smelled fresh from what I remember.
And Hearth peeps say ash drys out pretty quick. And in the late Fall the amount of water going through that tree is far less then right now. If I am wrong, please correct me.
 
fire_N_ice said:
muncybob said:
17% mc after 2 months on that ash!! Was it live or dead when cut? I surprised it's that low...the ash I'm currently cutting is 39% green.
.

Late fall, A tree service was taking down a neighbors ash trees and knocked on my door and asked me if I wanted it. I said sure and within minutes a constant parade of wheelbarrows full of logs went in my backyard. To be honest, Don't have a clue. It looked winter dead to me but. I thought it was alive b/c those trees had leaves on it in the summer. When I cut some of the rounds(b/c log length was 22-24") It smelled fresh from what I remember.
And Hearth peeps say ash drys out pretty quick. And in the late Fall the amount of water going through that tree is far less then right now. If I am wrong, please correct me.


F&N, is that a freshly split surface you were measuring in the photo, or did you just stick the prongs into the outside? Makes a big difference. You should grab a few more pieces and split them and measure right away in the center of the fresh face. If you did that already and got those results, your meter is defective or you are blessed with extraordinary drying conditions. BTW, I have the same meter and it seems accurate enough for the purpose of firewood testing. I didn't think that would be the case, but it held up well against a much more rigorous method of determining moisture content, so I'm a cautious believer... at least in my own meter.

As far as less water going through the tree in the fall, that's not necessarily true. I've searched the Internet pretty thoroughly for info about seasonal sap flow and there is not a lot of hard data available to support that claim. There are several regulatory mechanisms that trees use to control water flow (like opening and closing the stoma in the leaves, or varying the viscosity of the sap by changing the sugar content), and these mechanisms vary from species to species. Theoretically, the leaves are what pull the water up the trunk by establishing a pressure gradient to replace water lost through the leaves during evaporation. But there is lots of capillary action holding that water up way past the 32 feet that atmospheric pressure would ordinarily allow water to rise to. It seems that it can take a very long time for that water to fall down considering that capillary tension is pulling it back up. Since the tree is somewhat sealed by the bark, even standing dead trees can take a long time to drop moisture. Some folks here have claimed they've cut and split standing dead oak that squirts water at them when they try to split it. In the end, I guess you can say that it depends.
 
"F&N, is that a freshly split surface you were measuring in the photo, or did you just stick the prongs into the outside?"


Mine is a 12 dollar meter, not a $500.00 one . yes fresh split. inside middle measure. Could also be mine are split on the small side to begin with. If I throw in (the EM-42) anything bigger then say a 3"split, I have put out the fire within 45 minutes guarenteed.
 
Got my meter in the mail yesteday but did not have a chance to use it last night (Lodge Meeting), I will split some this evening and see how it its progressing and update.
 
Well I split or rather cut some logs with the chain saw last night to check the moisture and it is still too wet. The mesqite was in the 30-40% range and the oak was in the high 20's. Not sure if it will be dry enough to burn this winter but I have some old stuff that I had stock piled for my bbq pit that I could process, cut to length, but it is several years old and would sure be hard on the saw. I will check it again in a month and see it it is getting close. Not sure about the averaging thing that I saw on another post but I may have to try that too.
 
Status
Not open for further replies.