Moisture Meters

[ncrawshaw]

I've read posts about correct use of moisture meters so I thought I'd carry out my own experiment. I took a two year seasoned, split, sweet chestnut log from my dry, under cover stock. I measured the moisture three ways:

1. Along the grain in three locations
2. Across the grain in three locations
3. On the end grain in three locations

The averaged results were 20%, 18% 17%

Then I spilt and cut the log again to measure the moisture inside. The results, averaged again, were: 20%, 20%, 21%.

So it does look as though measuring on the end grain is the least consistent method, but they are all quite close.

[SimonFisher]

As you say, your log was seasoned and therefore having an almost uniform moisture level throughout. I'd expect it to show the same reading regardless of where you measured it and whether or not it was freshly split.

Try it on a log that's only partially seasoned. An exposed part or the end will have lower moisture level than the wood inside the middle of the log, which can only be tested by making a fresh split.

I recently measured some of my own oak that was felled about a year ago. Sure enough the ends gave readings of around 20%, which might have tempted me into thinking that they were ready to use. Splitting to reveal the middle on a few logs showed most of them still over 30%.

[Rich]

I felled some beech recently and was interested in it's moisture content, but my meter measured it at 30% . Clearly this is wrong, I would have expected it to be 50 or more. it was only a few quid from ebay the type with 4 pins, but it made me think just how accurate they are? Has anyone any experience of more accurate meters?

[SimonFisher]

I've a Euroheat AC101 (https://shop.euroheat.co.uk/misc.php?style=Wood%20Moisture%20Meter) which was about £46 when I bought it three years ago. I've never had any reason to doubt its accuracy. It has a test facility built into the cap - touch the pins across the cap contacts and it reads (I think) 27% to confirm it's working properly.

Rich, you could measure some of your beech doing an oven test to compare against your meter.

[Rich]

Rich, you could measure some of your beech doing an oven test to compare against your meter.

I could do, but I think it's just so obviously wrong! I just noticed in the instructions that it only has a range of 5 - 40%, might explain. but actually your one only seems to have a 6 - 44% range. Will it read 44% when you have an obviously greener piece of wood than that? or make up a figure like mine! I see yours has an auto off, that would save me £3.95 for a new battery each time I use it and forget to turn it off!

[SimonFisher]

The instruction sheet that came with mine indicates a measuring range of 1 - 45% with a reading of 45% means over upper limit / overflow.

The auto power off activates after 10 minutes, but it also powers off as soon as you replace the cap.

It also has replaceable pins (and came with two spares).