Moisture meter

[rakuz66]

Where can I buy a moisture meter? how much do they cost and how do they work? What moisture percentage is considered ready to burn? thanks.

 

[Battenkiller]

Here's a link to the one I use:

http://www.harborfreight.com/digital-mini-moisture-meter-67143.html

$12.99 plus shipping. It works really well, but you have to make sure the batteries are good. I started to get some extremely high readings from mine, then I saw that the battery indicator was on. Got new batts and it is right back to normal. Real small, so it fits in the pocket without being bulky. I'm pleased.

 

[tfdchief]

I have the same one. Great price and fairly accurate, as near as I can tell......comparing to relatively known moisture contents, like kiln dried and 2 - 3 year seasoned wood.

 

[Battenkiller]

I have the same one. Great price and fairly accurate, as near as I can tell......comparing to relatively known moisture contents, like kiln dried and 2 - 3 year seasoned wood.

Mine is real close to the results I get by doing an actual oven-dry test. Close enough for firewood, anyway.

One caveat. Moisture meters by their very nature are not really that accurate beyond 28% MC no matter how high the range shown. They work best when the wood is at or below the fiber saturation point - about 28% MC. This is straight from the engineer at Delmhorst, one of the biggest makers of professional quality meters in the world. When I asked him why their top of the line meter goes all the way to 60%, he said "Well, it tells you something, it's just not that accurate."

Whatever that means. :roll:

 

[tfdchief]

When I asked him why their top of the line meter goes all the way to 60%, he said "Well, it tells you something, it's just not that accurate."

Whatever that means. :roll:

That is strange, especially coming from an engineer of the product. It makes you wonder when you can spend $12.95 or $300.00 for a moisture meter.

 

[oldspark]

+1 on the Harbor Freight moisture meter.

 

[Lumber-Jack]

Where can I buy a moisture meter? how much do they cost and how do they work? What moisture percentage is considered ready to burn? thanks.

A reading of < 20% is usually considered ready to burn with prime efficiency. Wood with slightly higher MC will still burn, but you'll use more wood to get the same heat output and you'll get more creosote buildup in your chimney requiring more frequent cleanings. Wood over 25% is not really worth burning, it should be left to dry (season) for another year, or two.

 

[Battenkiller]

When I asked him why their top of the line meter goes all the way to 60%, he said "Well, it tells you something, it's just not that accurate."

Whatever that means. :roll:

That is strange, especially coming from an engineer of the product. It makes you wonder when you can spend $12.95 or $300.00 for a moisture meter.

All of them do the same thing - measure electrical resistance between the points and use a microchip to convert that resistance into an analog or a digital display as MC. The Delmhorst is a robust unit that can stand a lot of abuse in the field, has species correction programed into the chip, has extremely sharp, replaceable prongs, accepts a hammer probe that can sink as deep as 1 1/2", etc. One thing it can't do it to defy the laws of electricity.

I think what the engineer meant (aside from dodging a question he didn't see coming) is that a 60% reading would mean that the wood was wetter than a 50% reading, just can't be sure with wood how close is would be to real life MC. Interesting thing is that the Delmhorst species correction table only goes up to 28% MC. Shows you what they really know compared to what their top-of-the-line device implies.

 

[woodchip]

When I asked him why their top of the line meter goes all the way to 60%, he said "Well, it tells you something, it's just not that accurate."

Whatever that means. :roll:

That is strange, especially coming from an engineer of the product. It makes you wonder when you can spend $12.95 or $300.00 for a moisture meter.

All of them do the same thing - measure electrical resistance between the points and use a microchip to convert that resistance into an analog or a digital display as MC.

Which begs one question then.

If a moisture meter measure the electrical resistance between the points, is it an accurate way of measuring if you split a split, then drive the points into the fresh bit of wood (ie., the middle of the split), as you will not be getting resistance from point to point. You will get less resistance as there is more metal in contact with the wood and whatever moisture is there. Should you just press the points slightly against the newly split cross section?

 

[oldspark]

When I asked him why their top of the line meter goes all the way to 60%, he said "Well, it tells you something, it's just not that accurate."

Whatever that means. :roll:

That is strange, especially coming from an engineer of the product. It makes you wonder when you can spend $12.95 or $300.00 for a moisture meter.

All of them do the same thing - measure electrical resistance between the points and use a microchip to convert that resistance into an analog or a digital display as MC.

Which begs one question then.

If a moisture meter measure the electrical resistance between the points, is it an accurate way of measuring if you split a split, then drive the points into the fresh bit of wood (ie., the middle of the split), as you will not be getting resistance from point to point. You will get less resistance as there is more metal in contact with the wood and whatever moisture is there. Should you just press the points slightly against the newly split cross section?

I have stuck mine in there any way you can think of and it all seems to be the same as long as you do it firmly. Pleas take this post in context. :cheese:

 

[astrodon]

Interestingly, I just did an experiment this past weekend with my MM by drilling little pilot holes to let me sink the probe in further than I can without them. I just can't get myself to force my little $12 cheap meter into the wood like I got the impression you should do ( from the instructions or from here, I don't remember where I got that notion). Anyway, drilling the holes and pushing it further in gave no more than 2% higher readings than without the holes. So I just push it in as hard and as far as I think the cheap thing can take without breaking and call it good. 2% one way or the other doesn't change things for me.

 

[Woody Stover]

as you will not be getting resistance from point to point. You will get less resistance as there is more metal in contact with the wood and whatever moisture is there. Should you just press the points slightly against the newly split cross section?

Someone, I forget who, posted that you should press the points firmly into the wood, as that will give a higher reading than if you just touch the points to the wood. I have found that to be the case, as well.

 

[Battenkiller]

If a moisture meter measure the electrical resistance between the points, is it an accurate way of measuring if you split a split, then drive the points into the fresh bit of wood (ie., the middle of the split), as you will not be getting resistance from point to point. You will get less resistance as there is more metal in contact with the wood and whatever moisture is there. Should you just press the points slightly against the newly split cross section?

Less resistance equals a higher reading rather than a lower one. It is the distance between the probes that the meter is reading, not the amount of contact surface. When I said point-to-point, I meant "Point A" to "Point B". The probes are far enough apart that you needn't worry about slight discrepancies.

Even the cheapo meters are remarkably accurate over their range, but the accuracy of all resistance meters increases dramatically as the wood gets drier. Woodworkers are not concerned much with the difference between 20% MC and 30% MC since they won't be using the wood at these MCs, they are more concerned with the difference between 6% MC and 8% MC. At these low percentages, all of the meters are pretty much spot on.

 

[SpeakEasy]

Here's a link to the one I use:

http://www.harborfreight.com/digital-mini-moisture-meter-67143.html

$12.99 plus shipping. It works really well, but you have to make sure the batteries are good. I started to get some extremely high readings from mine, then I saw that the battery indicator was on. Got new batts and it is right back to normal. Real small, so it fits in the pocket without being bulky. I'm pleased.

I think I have the same meter, but when I looked into replacing the batteries I found that a new set of batteries cost more than a new meter!

-Speak

 

[Battenkiller]

Here's a link to the one I use:

http://www.harborfreight.com/digital-mini-moisture-meter-67143.html

$12.99 plus shipping. It works really well, but you have to make sure the batteries are good. I started to get some extremely high readings from mine, then I saw that the battery indicator was on. Got new batts and it is right back to normal. Real small, so it fits in the pocket without being bulky. I'm pleased.

I think I have the same meter, but when I looked into replacing the batteries I found that a new set of batteries cost more than a new meter!

-Speak

Ha, ha! Yup, just about. I got new batts at Wally World the other day. They come three to a pack for $5.99 Of course, the little bugger takes four batteries, so I had to buy two packs = $12. Hope I don't misplace the other two, they will allow me to get only a single pack the next two times they need changing.

 

[oldspark]

I just bought 4 batts. for a little over 5 bucks, guess I am lucky to get that price, maybe it would make some feel better if they were putting the batteries in a 50 dollar meter.

 

[wood-fan-atic]

Lowes sells one for $30.... made by General .... works for me...... takes a 9 volt battery.

 

[dafattkidd]

Here's a link to the one I use:

http://www.harborfreight.com/digital-mini-moisture-meter-67143.html

$12.99 plus shipping. It works really well, but you have to make sure the batteries are good. I started to get some extremely high readings from mine, then I saw that the battery indicator was on. Got new batts and it is right back to normal. Real small, so it fits in the pocket without being bulky. I'm pleased.

I think I have the same meter, but when I looked into replacing the batteries I found that a new set of batteries cost more than a new meter!

-Speak

Ha, ha! Yup, just about. I got new batts at Wally World the other day. They come three to a pack for $5.99 Of course, the little bugger takes four batteries, so I had to buy two packs = $12. Hope I don't misplace the other two, they will allow me to get only a single pack the next two times they need changing.

That's hilarious. I just got back from walmart and discovered the same fact. I may just go to harbor freight and buy a new one for the same price. The prongs on my meter are bending a bit anyway.

 

[DanCorcoran]

Yep, I bought the batteries at WalMart 2 days ago. A pack of 3 for $5.67, plus tax...two packs needed. When it comes to ranges, don't forget that the Harbor Freight meter has two scales, one of which is for use on sheetrock or plaster, rather than wood. That may account for why the range goes higher than you'd care about, when it's on the wood setting.

 

[Pete Kurki]

Which exact battery is this moisture meter using? I'm thinking about buying one as well, but the HF specs in the web site do not mention which battery it takes. I usually buy all the button batteries in bulk from internet. Just ordered 10 pieces of LR44 from Amazon for $2.37 + free shipping. My digital tire gauge uses 3 of these at the time.

 

[oldspark]

Which exact battery is this moisture meter using? I'm thinking about buying one as well, but the HF specs in the web site do not mention which battery it takes. I usually buy all the button batteries in bulk from internet. Just ordered 10 pieces of LR44 from Amazon for $2.37 + free shipping. My digital tire gauge uses 3 of these at the time.

The HF one has LR 44 so you are good to go, I am off to Amazon to look, thanks for the tip.

 

[Battenkiller]

Which exact battery is this moisture meter using? I'm thinking about buying one as well, but the HF specs in the web site do not mention which battery it takes. I usually buy all the button batteries in bulk from internet. Just ordered 10 pieces of LR44 from Amazon for $2.37 + free shipping. My digital tire gauge uses 3 of these at the time.

I would have looked there but I needed to use the thing right away for something urgent (leaky basement related). I will be sure from now on that I have plenty on hand from a supplier on the web.

 

[Black Jaque Janaviac]

I see Ace Hardware has one that is $21 but only needs a 9v battery. So after a number of battery changes the extra $8 would pay for itself. I've noticed that with a number of digital things - you can get some cheapo things but good luck finding a battery for it, or you can pay more and get something that takes a more common battery.

(broken link removed to http://www.acehardware.com/product/index.jsp?productId=3890605&kw=moisture+meter&origkw=moisture+meter&searchId=52993267324)

 

[DanCorcoran]

I see Ace Hardware has one that is $21 but only needs a 9v battery. So after a number of battery changes the extra $8 would pay for itself. I've noticed that with a number of digital things - you can get some cheapo things but good luck finding a battery for it, or you can pay more and get something that takes a more common battery.

(broken link removed to http://www.acehardware.com/product/index.jsp?productId=3890605&kw=moisture+meter&origkw=moisture+meter&searchId=52993267324)

Or, buy the cheaper Harbor Freight model and pay 23 cents each on Amazon for the batteries (total of 92 cents per changeout).

 

[chile verde]

I think I have the same meter, but when I looked into replacing the batteries I found that a new set of batteries cost more than a new meter!

-Speak

http://www.harborfreight.com/24-piece-button-cell-battery-multi-pack-97072.html

$4.99, plus 20 additional bats for whatever dead watches might be lurking in your nightstand.