Moisture Meter(s)

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AsylumResident

Feeling the Heat
Mar 23, 2023
254
NE Wisconsin
I have a cheaper moisture meter that basically just turns on, stick the prongs into the wood and it gives me a reading. There are no settings or options.

I bought a second moisture meter that was a little more expensive that has options. Before I test I can choose soft wood, hardwood, building material.

I split a piece of black locust, selected hardwood on the moisture meter, and on the fresh face took a reading. It was 18%. For comparison I also took a moisture reading with the cheaper moisture meter and the reading was 31%. So what is the moisture content? Do I really need to buy a third moisture meter to triple check this stuff? That's a pretty big discrepancy.
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Just for yucks, try the other settings (softwood, construction) Does it read radically different?
What does your intuition tell you based on how long it's been seasoning. If you take the freshly split face of the wood up against your cheek, does it feel cool and damp or dry?
 
Just for yucks, try the other settings (softwood, construction) Does it read radically different?
What does your intuition tell you based on how long it's been seasoning. If you take the freshly split face of the wood up against your cheek, does it feel cool and damp or dry?
The other settings give drastically different readings.
 
The other settings give drastically different readings.
That may indicate a defective meter. The range should change, but for say a 12% mc split, the reading should be the same.
FWIW, I have the same General MC meter as Caw. It's worked well for years.
 
That may indicate a defective meter. The range should change, but for say a 12% mc split, the reading should be the same.
FWIW, I have the same General MC meter as Caw. It's worked well for years.
I have the same general mc as well. But never tested it against another. Using the cap test though it was right on.
 
These are my tools and they've served me well over the years:
My meter is a close relative of that: a General MM9. A pin + pinless Home Depot version. I don't have any reliable way to calibrate it, but the readings seem reasonable for length of time drying, wood species, and burning results.

My IR thermometer is a Fluke.
 
Why would it matter if it’s hard wood, soft wood or building material? Is is 20% moisture in pine firewood different than 20% moisture a 2x4?
 
That may indicate a defective meter. The range should change, but for say a 12% mc split, the reading should be the same.
FWIW, I have the same General MC meter as Caw. It's worked well for years.
Well the readings will change a bit because the conductivity of different woods is different. Good ones either come with correction tables or have different settings for different species. But I have never seen any drastically different between species. It's just a few percentage points
 
Well the readings will change a bit because the conductivity of different woods is different. Good ones either come with correction tables or have different settings for different species. But I have never seen any drastically different between species. It's just a few percentage points
That's exactly why I brought this question up. I've never used moisture meters before so to get such different readings just by changing the setting from hardwood to softwood really threw me for a loop.
 
These are my tools and they've served me well over the years:

View attachment 319472

That may indicate a defective meter. The range should change, but for say a 12% mc split, the reading should be the same.
FWIW, I have the same General MC meter as Caw. It's worked well for years.

I have the same general mc as well. But never tested it against another. Using the cap test though it was right on.
General MMDE4 pins kinda slated by an Amazon review by "pro" firewood supplier

My research continues...
 
I'm not following. I assume you meant to say slanted so one bad review on Amazon versus everyone here telling you it's great value and you're out?
 
I'm not following. I assume you meant to say slanted so one bad review on Amazon versus everyone here telling you it's great value and you're out?
slated is what I wrote and what I meant :)

it means a negative review in this regard
shall I quote him, then? There are +12,000 reviews of this MM
Firewood business means more wear and tear than consumer/ prosumer
I'm certainly a prosumer...I'll keep looking for more info anyway...

here we are (it is an amazon.fr link, so language!):
https://www.amazon.fr/product-revie...r&reviewerType=all_reviews#reviews-filter-bar

3 star review:
"We have a fire wood business and a moisture meter is a must to ensure our wood is seasoned. This meter works great, but the pins bend, warp, and the tips curl after using it for a day. So I replaced the pins with the two the meter came with. Within 45 minutes the tips were bent again. We are using it to measure hard and soft fire wood. We are not rough or over zealous with the meter. I just looked up replacement pins and they are $15! That’s half the cost of the meter. If I am going to have to replace pins nearly every day that’s going to add up to a crazy amount of money. Overall, If the pin issue was fixed this would be a perfectly good moisture meter.

Update: I spoke with the manufacturer today and they confirmed that this meter’s pins are not built to withstand testing firewood. Also said it is not a manufacturer problem, it’s the woods problem 🤔, so even through it has a year warranty, this isn’t covered under it. He suggested I try a more rugged brand or a pinless meter. I wish I had come to this conclusion before the return date was up for Amazon."
 
I'm certainly a prosumer
Are you selling firewood? I don't have any issue with anyone wanting a more rugged machine. That's your prerogative.

What I'm suggesting is that you really shouldn't need to use it very often for firewood. Grab one or two pieces per cord stack to test. You can assume the rest of that stack is similarly dry. I don't use mine very often just if I'm curious how a new stack is progressing once in a while. After burning a while it's pretty easy to tell when the wood is dry by weight and sound.
 
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I have not bent mine yet. I use it in mostly oak and am careful not to crank it in to crazy hard.
 
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Are you selling firewood? I don't have any issue with anyone wanting a more rugged machine. That's your prerogative.

What I'm suggesting is that you really shouldn't need to use it very often for firewood. Grab one or two pieces per cord stack to test. You can assume the rest of that stack is similarly dry. I don't use mine very often just if I'm curious how a new stack is progressing once in a while. After burning a while it's pretty easy to tell when the wood is dry by weight and sound.
I am not selling firewood, the fellow who provided the review I shared said he was.

I do have a lot of woodworking projects and several rental properties and I am the carpenter for all of this wood stuff in my life. I like high end tools. I don't do very well with assumptions. The firewood my current supplier is delivering is a bit all over the shop...which I only know by weight and then burning in the stove. I have about 8 years of firewood to test...I can't really assume time will tell the truth...burning the wood has taught me that.

Anyway, even stretching to a Wagner 950 wouldn't be out of scope for me needs...I can't really afford it, but I might have to find a way

research continues...
 
make your own subset of pins that you can hammer in and pull backout or screw in same deal & back out, You need about a 1/2" penatration. some nonconductive material to keep the spacing the same, then touch units pins to that. on any of these the material to be tested needs to be at room temp, cold or frozen is going to give false readings, that can be compensated for with a little math. a piece of dressed lumber kept dry at room temp should come in at about 12% just as a referance point. surface of your arm should just about over scale. A volt /ohm meter used on the resistance scales can be used quite nicly also . These meters are very basic ohm meters- just reading the restance between two points. there are articles on how to set up a calabration range system on the net.
 
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make your own subset of pins that you can hammer in and pull backout or screw in same deal & back out, You need about a 1/2" penatration. some nonconductive material to keep the spacing the same, then touch units pins to that. on any of these the material to be tested needs to be at room temp, cold or frozen is going to give false readings, that can be compensated for with a little math. a piece of dressed lumber kept dry at room temp should come in at about 12% just as a referance point. surface of your arm should just about over scale. A volt /ohm meter used on the resistance scales can be used quite nicly also . These meters are very basic ohm meters- just reading the restance between two points. there are articles on how to set up a calabration range system on the net.
I do have a DMM Extech EX350 (talk about beer budget 🫣)

I’ve read on hearthDOTcom and other places electrical interference can be a headache when using a DMM for firewood moisture measuring…I have not tried it

I feel like I need something trustworthy to reference against…like using a very good level to check if your “working” levels are giving good feedback