What moisture meter do you use?

[Brucer]

Mine is a Timber Check. It has pins built into the body. Turn a dial on the top until a red LED on the side comes on. Then read the dial.

Common moisture meters come in two styles - resistance and electromagnetic. The ones with pins are resistance meters; they're very simple and they've been around for a long time. (You could build your own if you were so inclined). They measure the resistance of the wood over a fixed distance (the distance between the pins), then translate it into a moisture reading.

The resistance of wood increases as it gets drier so you will always be measuring the highest moisture content that the pins can reach. The relationship between resistance and moisture can vary depending on the species and the temperature of the wood. Usually a meter will come with a chart to adjust the reading for different species and temperatures.

One thing you really have to watch for with the pin-type meters is that the pins are straight, parallel, and smooth. Any deviation or roughness can create a gap between the pin and some of the wood. That increases the resistance and makes the wood appear a lot drier than it actually is. I've seen a meter with badly bent pins (not mine ;D) give a reading of 6% when the actual value was 14% . I always carry a pair of smooth jaw pliers in my tool box to straighten the pins.

The best resistance type meters have hammer-in pins. The pins are mounted in a sturdy non-conducting block and there is a heavy handle the slides on a steel rod attached to the block. Just slide the handle up and down to hammer the pins straight in. The kind like mine with built-in pins tend to bend the pins as you lever them into the wood. I wouldn't want one like mine is I were dealing with hard wood.

Resistance type meters have a useful range of about 6% to 25% and over. The resistance of the wood doesn't change much outside this moisture range. A 25% reading can mean just about anything above 25%.

The electromagnetic ones like the Wagner MMC220 don't need to penetrate the wood. An electromagnetic signal is sent into the surface and bounces back a signal that varies according to the moisture content. The moisture range it can measure is a little broader, especially at the high end. You still have to correct for species.

For the work I'm doing, mainly in softwoods, the pin-type meter is perfectly adequate. If I were selling wood (or processing it) according to moisture content, I would probably spend the bucks on a Wagner.

[Kbeitz]

When checking wood that you have been drying for a while do you need to cut a chunk off to get to the center for a good reading ?

[ScottInCabot]

Sort of embarrassed to even mention it, but since it compares to more expensive models(tested)...I'll go ahead.

Home Depot Ryobi E49MM01(think it was discontinued-probably because it actually works and came from HD)....and it only cost $39!!!!  Just have to remember to bring a 9v battery, or you'll wonder why it isn't working at all(DAMHIKT)


Scott in Cabot

[Brucer]

When checking wood that you have been drying for a while do you need to cut a chunk off to get to the center for a good reading ?

Depends. A resistance type will give you the moisture reading near the end of the pins. If that's close to the centre, you're good. The other types will usually tell you how deep they are measuring (usually not more than 3/4").

The best way to get a reading deep into a thicker piece of wood is to cut a board in half and then take a measurement on one of the cut ends. If it isn't dry enough, leave the two halves in the kiln and cut one of them in half when you want to take another reading. Remember that wood loses moisture faster out the ends to any reading taken near the ends will read on the low side.

[Kbeitz]

So whats a good number for planning or sanding ?

[WDH]

12% and below has worked well in my experience. 

[BCsaw]

Brucer, thanks for your post. I was looking at the Timber Check. I would like to have an idea of moisture content in my wood. However it is not critical. I did not want to spend a ton of money but I did not want to waste my money either.  ;D

[OffGrid973]

Mini Lingo has treated me well...two settings for different types of woods.

[Brucer]

BCSaw -- I've had the Timber Check for about 10 years now and it stood up well. It was designed to be simple and rugged.

You have to be sure you've switched it to the OFF position after you've taken a reading. Otherwise you'll forget and wear out your battery -- and you have to undo a screw to replace the battery.

Biggest problem I've had is pushing it into a hard surface (carefully so as not to distort the pins) only to realize that I've got the LED's facing away from me >:(.

[Compensation]

I use a General. It's the fastest one I could get that day and it's done a good job so far.

[Bandmill Bandit]

Mini Lingo has treated me well...two settings for different types of woods.

exact same as mine and it has worked well for me.

[bkaimwood]

My previous post about my cheap pinned Wagner meter being pretty close and reliable has recently come into question...I still think it has been great for the money, and has been close, and reliable...BUT.. I just checked some good sized walnut slabs that have been in the kiln FOREVER, last load to come out...it checked out 8-10% on surface and sub-surface checks, but after cutting a slab, I got readings as high as 25%!!! Yes, I know, this screams case hardening.. BUT, I find this hard to believe, as this walnut was air dried for months, then in the kiln for months...and its a low temp kiln...it reaches peak temps of 120, but rarely, more commonly in the 95-100 degree range...no fan overkill, regular destressing cycles overnight, with everything off, and so on...I'm thinking maybe this meter is good for standard grade lumber up to maybe 6/4 max, but its performance lacks past that... I think the most important detail is I deal with mostly 8/4-12/4, and these slabs are 28" wide...so maybe I need to spend 250-300 bucks on a pinless, high quality meter? Your thoughts gentleman?...

[DR Buck]

I use the Delmhorst J2000.  It's been excellent for about 10 years with only ocassional battery replacements.

[logboy]

I have thick (8/4) wood in the kiln right now and the slide hammer with the longer pins are sure coming in handy.


 

I have the exact same setup.  I used a mini Ligno for years but started having a hunch it was lying to me about stuff coming out of the kiln. After buying the Delmhorst it confirmed that it was telling me stuff was dry when it really wasn't.  Some of the readings on the Ligno were 4% different than the Delmhorst.

[Brucer]

Remember, those pin-type meters are actually measuring the resistance of the wood between the pins. Drier wood has a higher resistance. The meter will measure the lowest resistance (greenest) wood between the pins.

If the pins only penetrate the surface, you'll get the surface moisture. If they penetrate deeper, you'll get the higher moisture reading near the tips (and the dry surface will be ignored).

If the pins are bent or rough, they won't make good contact with the wood. That will increase the resistance a lot and your meter will give an artificially low moisture content.