Moisture Meter

Bill Gaiche · March 21, 2014, 10:05:08 PM

I have been using a pin meter and I have broken several pins in the wood. Its not easy to push in and pull them out when the wood gets dry without eventually breaking one.
So I ordered this one tonight Wagner MMC220 pin less. bg

GeneWengert-WoodDoc · March 21, 2014, 10:44:00 PM

They do make 1/2" long needles that are much less prone to breaking.

Bill Gaiche · March 21, 2014, 11:38:10 PM

I have the 7/16", they are tempered and the first 1/16" or so is what breaks off. I thing they need to be a little softer so they don't snap off as easy. bg

Magicman · March 22, 2014, 10:27:19 AM

Bill, my Wagner is analog (pre-digital readout) but I have been pleased with it.

Bill Gaiche · March 23, 2014, 10:38:03 AM

MM, I had studied the Wagner brand and it seems they were the first to make a pin less meter,also reviews show that they are supposed to be one of the best, hope so. bg

GeneWengert-WoodDoc · March 23, 2014, 10:22:13 PM

There are plus and minus factors for both meters...for example, the pinless is very sensitive to density changes and cannot measure a gradient within the lumber (that is, shell and core). The pin meter is sensitive to wood temperature, cannot measure under 6.5% MC, and takes more effort to use (slower and takes more time to extract the broken pins). In either case, spend more than $200 to get a durable, reliable model.

Perhaps the best approach is to use the pinless and then when you get a reading that is too high, double check it with the pin meter.

Both meters will get really close to the true MC. Check the write up in DRYING HARDWOOD LUMBER for a comparison.

The problem 9 times out of 10 is operator error. Example: I had one complaint yesterday where the pinless was used on a stack of wood and gave a high reading, but the oven test was OK. The pinless meter must have an air space under the piece of lumber and not another piece of wood. In this case, measuring the top piece of a stack, they would get higher values than if they had an air space under the piece being measured.

Escavader · March 24, 2014, 05:32:01 PM

I use the pinless wagnerl22 with attached wand it's really nice cause I can reach way inside the pack between the stickers pricy but we've had it a long time now and no more take it out of the kiln and put it back in cause you guessed wrong

longtime lurker · March 24, 2014, 07:02:45 PM

I use a Delmhorst J-4. It's been pretty good so far though I've broken a few sets of pins off - they're a wear part, that's why they're so easy to replace. It also comes with a slide hammer set of pins for deep readings in dense timber: don't use it often but I think it'd be difficult to shear them off.

beenthere · June 18, 2014, 10:34:46 PM

Here is a Woodworkers Journal basic vid on moisture meters if interested.

http://www.woodworkersjournal.com/resource/JigBasedJoinery/MoistureMeter/index.html

WDH · June 19, 2014, 07:31:23 AM

I have a Wagner MMC210 pinless and a Delmhorst J-2000X. The J-2000X is designed for use in kilns and is supposed to be able to measure moisture content up to 60% moisture. Anyone with any experience with the "X" version of the J-2000?

scsmith42 · June 21, 2014, 10:21:44 PM

Quote from: WDH on June 19, 2014, 07:31:23 AM
I have a Wagner MMC210 pinless and a Delmhorst J-2000X. The J-2000X is designed for use in kilns and is supposed to be able to measure moisture content up to 60% moisture. Anyone with any experience with the "X" version of the J-2000?

I have a J2000x, and older R2000, and a Merlin pinless. I have never had a problem with breaking the pins with the J2000X meter. The Merlin is fast, accurate, and reads deep into the lumber.

GeneWengert-WoodDoc · June 22, 2014, 07:31:02 AM

The problem with all moisture meters is that the electrical property that they measure is not closely related to moisture content above 30% MC. Hence, the estimate of MC is not very close to the true MC. The meter itself measures the electrical property just fine, so it is not an issue with the meter itself...although some foreign made meters do not measure the electrical property very well...the problem at high MCs is in the wood.

WDH · June 22, 2014, 08:07:12 AM

So, you would not trust the readings from the J2000X above 30%? Delmhorst advertises that it will measure to 60%.

beenthere · June 22, 2014, 10:44:16 AM

Here is some Delmhorst info from a slide show.. it appears.

http://www.esf.edu/nekda/documents/UsingWoodMoistureMeters-AlanDuglash.pdf

Would be interesting to know if anyone has actually measured above 30% and the weighed and dried samples to check variability at high MC's. Maybe Delmhorst has some backup info available to support their claims.

WDH · June 22, 2014, 08:08:36 PM

Looks like that I need to conduct an experiment.

Den Socling · June 22, 2014, 08:19:03 PM

Do it!

GeneWengert-WoodDoc · June 22, 2014, 08:23:56 PM

If you note slide #5, Delmhorst says readings over 30% MC are qualitative.

They also give the accuracy under 30% MC, which means that 2/3 of the readings at low MCs will be within plus or minute 3/4% MC under the best conditions.

Again, this variation and difficulty over 30% MC reflects the fact the electrical resistance does not translate perfectly into MC.

I had a student do research on this meter being used over 30% MC. Sometimes it was close and other times it was off quite a bit. However, if you knew the initial MC and could "re calibrate" the meter for each individual piece of lumber, this custom calibration allowed a very close estimate of MC. For this test, we used the Delhorst needles that are driven into the wood and then left in the wood during drying. This avoids variation from driving the needles to different depths.

WDH · June 22, 2014, 08:34:59 PM

I use the meter with 1" pins and the slide hammer. This puts the tips of the insulated pins into the center core of the boards. I use the same pin holes to test for M% after I have hammered the pins in initially. Delmhorst said that it was OK to use the same pin holes to test the moisture on subsequent days. Does anyone else use the slide hammer, long pins, and the same pin holes to measure M% over the course of a kiln cycle?

Larry · June 22, 2014, 08:51:41 PM

I have an Electrophysics MT808. It will read up to I think 100%. Its programmable for temperature and species. I have compared it against oven dry samples and it is right on when less than 20%. Above 20% it looses its accuracy. Above 40% I may get a different reading in every spot I test on the board. At 60% the readings will really vary from one end of the board to the other.

Above 30% I just figure the wood is wet and don't worry too much about a specific reading. I tried to monitor moisture loss each day in both my solar kiln and dh kiln by using pins connected to cable running to the outside, where I took a reading each morning/evening. That ended in frustration as I think my lamp cord cables absorbed moisture. I also wondered if voltage from my meter was drying the wood at the location of my pins. I had a lot more confidence in my oven sample. After a few loads I got used to what was happening and didn't check moisture or do samples till near the end.

I'll be interested to hear what you come up with using the J-2000.

Den Socling · June 22, 2014, 09:04:54 PM

I would really refrain from using the same pin holes. They are exposed to the atmosphere. In a vacuum kiln, this is very apparent. You can't use probes in a vac kiln and I wouldn't use the same holes in any kiln.

GeneWengert-WoodDoc · June 23, 2014, 06:18:59 AM

I believe that you can leave the pins in the wood without much problem, but you cannot remove the pins and then use the same holes on another day during drying. However, it is best to use new holes (new location) for every test for the most accurate results.

WDH · June 23, 2014, 07:07:45 AM

This is a good discussion. Delmhorst told me that when you hammer in the pins and take one reading, that is the only one that will be accurate. If you then take repeated readings without removing the pins in the same spot, you can get a different reading because the wood fibers relax.

hackberry jake · July 01, 2014, 04:49:43 PM

I got the delmorst j2000 with the slide hammer. It is by far the best meter I have ever used... course the only other meeter I ever used was a $40 chinese piece of.... junk, yeah. Junk.