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Moisture Meter

Started by oldmatelot, October 06, 2012, 08:12:12 AM

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oldmatelot

Do you people use same - and if so any recommendations?

Den Socling

A Delmhorst J2000 is as good as any. If you want to check anything more than 4/4, get a slide hammer with the meter.

Tree Feller

Quote from: oldmatelot on October 06, 2012, 08:12:12 AM
- and if so any recommendations?

That's akin to asking "which tablesaw should I buy?"   ;D

Wagner, Delmhorst and Lignomat all make accurate, reliable moisture meters, especially if you go with one in the $200+ price range. (The Delmhorst J2000 is $309 at amazon)

Both pin meters and pinless meters have advantages. Pin meters can measure moisture gradient in a board, especially if using a slide-hammer accessory. Pinless meters can scan an entire board in one pass and also read MC below 6%. In a perfect world, one would have both.

I have a Lignomat MiniED and for my needs, it is as accurate as I need. I don't sell lumber so all I want to know is if my lumber is dry enough for building indoor furniture. The Lignomat tells me that and it only cost around $100 but I sometimes wish I had ponied up the bucks for a better model with more features.

A moisture meter is a long-term investment and it's probably wise to get the best you can afford, especially if lumber is a business.
Cody

Logmaster LM-1 Sawmill
Kioti CK 30 w/ FEL
Stihl MS-290 Chainsaw
48" Logrite Cant Hook
Well equipped, serious, woodworking shop

Den Socling

Pinless meters like Wagners do make it possible to check multiple boards at multiple locations in a hurry but you do need to take some care. If you slide them over dry wood, static can blow them. At least, this was the case in the past and I don't know how Wagner could have corrected the problem. Just lift them from spot to spot. Don't slide them the length of a board.

GeneWengert-WoodDoc

If you are selling lumber and MC is important, use the same meter as your customer, as different meters will give different answers.  Otherwise, specify that the MC is based on readings from a certain model and manufacturer.

One feature of the pinless meter is that it is significantly affected by the density of the wood, so a high MC reading could be because the particular piece is a bit high in density for the given species.  The pinless meter gives an average MC at the location where it is used, but it must have air underneath the piece, especially with 5/4 and thinner.  If no air, the MC will be a percent higher ro so.  The pin meter measures the wettest MC when using uninsulated pins, along the pin's length.  Insulated pins allow the MC to be measured at the tip of a pin so you can measure the surface MC, the core MC, etc., but only at one spot.  The pin meter is sensitive to temperature of the wood...cold wood reads lower in MC than actual.

As mentioned already, having both types of meters, costing $200 or more, is the best when selling to make sure that you will not get a MC complaint...which can be expensive to deal with, even if you are correct.  Be aware that many customers have cheap, non-standard meters and / or fail to use the meters correctly.  (I recall one customer that had a complaint and when I went to check it out, I asked the customer, who claimed he measured MC all the time, what size battery the meter used and where they kept the extra pins...they did not know, so it seemed that the MC claim was bogus indeed.  It is often a false claim from a customer unfortunately.

If selling, always measure the MC of 8-10 pieces when the load is shipped to confirm that the MC is correct and to give you the advantage if there is a complaint.  The customer may have high MCs, but maybe you had the correct MC and it gained in shipment or storage.  Incidentally, the core MC takes a long time to change, so measuring the core MC with insulated pins tells you the MC when the lumber left the kiln.  If the core MC is lower than the shell MC, then you are certain that the lumber gained MC AFTER it left the kiln.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

red oaks lumber

moisture meters are like compass's. only have 1, trust and believe in it.
you get what you pay for :)
the experts think i do things wrong
over 18 million b.f. processed and 7341 happy customers i disagree

kelLOGg

Quote from: GeneWengert-WoodDoc on October 07, 2012, 02:34:34 PM
The pin meter is sensitive to temperature of the wood...cold wood reads lower in MC than actual.

Glad to read that!. Even though my meter has automatic temp compensation I read about 2+% less at 70 deg than I do at ~125 deg. Thought it was a defective meter.

Bob
Cook's MP-32, 20HP, 20' (modified w/ power feed, up/down, loader/turner)
DH kiln, CatClaw setter and sharpener, tandem trailer, log arch, tractor, thumb tacks

GeneWengert-WoodDoc

I have seen that automatic temperature correction does not work as well as manual correction.  I believe it is because it is easier for a Human to figure out the wood temperature then for a probe...use the kiln dry bulb for dry wood.  It takes time for the wood to change temperature, so the present air temperature may be incorrect.  On the other hand, 20 F is just 1% MC.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

GeneWengert-WoodDoc

I forgot to mention that when you measure the MC of 8-10 pieces just before shipping, write the MC on the lumber in big numbers with a marker so that the customer knows you have checked the MC.  A second choice is to write the MC readings on the shipping invoice, again to let the customer know that you are on top of things.

Here is an idea...why not guarantee that the MC is correct or the customer can get double their money back?  If you could not do this, maybe you need to work a bit harder to make sure you have the correct MC...such a guarantee would certainly set you apart from the competition and might increase your customer base greatly.  You could even raise the price to reflect the higher quality lumber you sell.  Less than 20% of the hardwood customers are concerned about price;  quality is their #1 concern.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Tree Feller

Nice avatar, Doc......for an old fart!   :D :D :D

I can say that because i are one, too.   ;)
Cody

Logmaster LM-1 Sawmill
Kioti CK 30 w/ FEL
Stihl MS-290 Chainsaw
48" Logrite Cant Hook
Well equipped, serious, woodworking shop

lowpolyjoe

I didn't want to start a new thread for essentially the same question....  good info in here.  :P

I am hoping to cut my first boards shortly.  After drying i hope to use them in some projects around the house.  It's strictly hobby work, so i am not answerable to anyone but my wife  ;)

I researched moisture meters briefly and found this interesting website describing some manual measurement techniques using a multimeter.  Can anyone comment on the multimeter approach?  Is it reasonable for a one-time project?  I would rather not spend several hundred $ on a good moisture meter but i don't want to buy a cheap one and get inaccurate values.   

http://woodgears.ca/lumber/moisture_meter.html

Also a nice link to a pdf from the US Forestry service on that site:

http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr06.pdf

Thanks,
Joe

GeneWengert-WoodDoc

Here is the probleM with the multimeter.

12% MC is 120 million ohms
7% MC is 12,600 million ohms.

On a multimeter, such high resistance cannot be measured accurately or with any resolution.  The difference in a needle movement is almost nil.  Digital cannot do it either, as there are too many resistance leaks.

Spend no less than $200.  For a made in USA meter.  You will have a reliable, accurate meter that will have value and usefulness 19 years from now too.  It can be repaired easily and quickly when you drop it or run over it.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

lowpolyjoe

Thanks for the feedback Gene.   

Part of the link I posted details a method for setting up a circuit (with a 9V battery i think?) to measure those extremely high resistances using a normal meter.  I'm no where near ready to measure moisture content since my DIY saw mill setup is more challenging than i expected.  But in the coming months i'll have to either read that article more closely or keep a lookout for a good deal on a moisture meter.  $200 is a bit more than i'm budgeting for this hobby project but i have definitely grown over the years to understand the value in quality tools.

Thanks,
Joe

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