Types of Moisture Meters

So you finally have determined that your woodworking merits having a moisture meter in your shop. You know it's important because you've gotta know the moisture of the material that you're working with in order to make sure that it's stable before you start investing your labor into that project. What that means is that you're to a point where you're looking at all of these moisture meters and trying to figure out what's the best one for me. So that's what this is all about. I want to try to help you make buying decisions about the moisture meter that works best for you and what different moisture meters offer. So, first thing let's define moisture meters into pin meters and pinless meters. This one here on the end, this is a meter with pins. Now here's what happens. I project these pins into my workpiece. Different sets of pins come with the moisture meter. So in order to get deeper penetration, I can change to a longer set of pins. Now, the impact of that is that we want to make sure when we're taking moisture meetings that we get the penetration that we need to get an accurate reading at the right depth. So a couple of things here with this meter I'm going to have to push those pins into my work, which does mean I'm gonna leave two little snakebite holes in there. Also, you've got to be able to push hard enough to get the penetration that you want which in some harder woods can be a little bit difficult. That takes us then to pinless meters. So this meter over here doesn't require any pins. What it does is it puts a signal out the backside. That signal does kind of a three-dimensional read into the thickness of your material in order to get the moisture content. Now here's the difference between the two from a little bit of an accuracy perspective. With the pin meters what's happening is that from pin to pin, it's taking a reading at that location. With the pinless meters, it's taking more of an average reading of all the material that that signal is reading through. So one of the things that we want to pay attention to, if you're choosing to go down the pinless route, is to make sure that you're looking for a meter, looking at a meter that allows you to control the depth of your reading. So many meters allow you to set the depth, commonly at 1/4 inch or 3/4 inch depth, that allows you to take readings at the center of different thicknesses of materials. So where with the pin meters, we would control the reading location by how far you can push the pins in, With the pinless meters, we control it by setting electronically the penetration that we get from the electronic reading of the meter itself. Now, the other thing we have to consider here is specie correction. Not every wood is gonna read the same. So if we come back to this meter on the end, you can see on here, there's a two and a three. So those are wood groups. When I look at the chart that comes with the meter, I can tell some species are in one group, some species are in another, so I set the meter to one of those two groups and I get my reading. On other meters, like these I'm looking at down here, they have a more finely tuned specie correction. What it allows me to do is look at the chart. When I look at the chart, there are numbers attached to different species of wood. So then I would bring this chart to my meter. I would set for that specific number on this specific meter. And that same thing is true all the way down here, including into these pinless ones. So what you're looking at there is you're fine tuning your moisture content reading a little bit more because you're dialing in that specie correction a little bit tighter with these meters. The other thing that we can look at here is if we've got a big pile of rough-sawn stock and we want to really make sure that we're getting good penetration on thicker material, then you're ready to look at probes like this one. So with this, when I set this on my material, I can drive those probes very deeply. And now what's cool about this is that notice that the pins themselves are insulated. So I'm getting a reading from here to here, not from here to here. So the other thing that's kind of cool out of this is that on thick stock with just a little bit of penetration, I'm getting a surface reading of moisture content. Every time I tap it more deeply, I'm getting a reading that's deeper and deeper and deeper into the wood specific to that specific penetration point. So this can give you a lot of accuracy on that thicker stack. What if you've got a pile of stuff in the kiln and you want to make sure that boards you have all the way in the middle of the kiln are drying at the proper rate, you wanna know when they're dry, then you can look at setups like this. These probes are gonna get placed into the material, the wires trail out. Then as I come to the kiln, I can plug these wires into my moisture meter, get the reading, leave with my moisture meter. So of course we don't want the moisture meter forever inside that kiln environment where you're drying wood. So I can use this as needed to just kind of monitor the pile, have these in a couple of different spots in the pile. You're gonna get good, accurate readings throughout your kiln. Last thing here on these pinless meters, it's a good thing to know about, is that the pinless meters work best on a fairly smooth surface. So a couple of ways around this, if you're working on rough-sawn stock, it's a good idea to take a block plane and just slightly smooth that a little bit so that when we put the two sensors on the back of the pinless meter onto the material they have the opportunity to make good contact and lay nice and flat on there. Lots of different stuff on the marketplace, lots of choices you can make. But the important thing is that you get a moisture meter into your shop to make sure that you're accurately reading the material that you're using, make sure it's nice and stable before you start that project.