CMT’s Inexpensive Moisture Meter

If you ever work with wood from unreliable or unusual sources, such as one-person sawmills, it pays to own a moisture meter. I slip mine into my pocket whenever I head to the lumberyard and it has saved my skin several times in the last 20 years.

But not everyone can afford an expensive pinless meter with all its features.

So I was interested to try the new CMT DMM-001, a pin-activated moisture meter that costs about $40, or about one-fifth of the price of a nice commercial meter.

On the plus side, the CMT has a rugged case, is simple to operate and comes with the 9-volt battery that runs it.

On the minus side, all pin moisture meters have limitations. You have to drive the pins in fairly deep to activate the meter, and so you don’t want to use the meter on wood that will be a show surface – the pins leave obvious holes.

The other limitation is you cannot calibrate the meter for the specific gravity of the wood species. Expensive meters allow you to adjust for wenge or white pine. So you are unlikely to get a dead-on correct reading. After comparing the CMT to my own meter, I think the CMT is calibrated for something between oak and maple, which is a perfectly reasonable setting.

This limitation means that you can get only relative readings instead of absolute ones. So test some maple that has been sitting in your wood rack all year then compare it to the maple at the lumber yard. You’ll know whether the maple is wet or dry.

In other words, it’s definitely useful, and at $40 it’s silly not to have one from a reputable company such as CMT.  PWM

— CS