Moisture Meter

[Ironballs]

I've been after a decent moisture meter for a while and like Ed had my eye on an Electrophysics one, until they stopped selling them... Now being a bit tight I didn't fancy paying 100 plus quid for a bells and whistles one, especially as I don't need it to be that accurate and it won't get used all the time.

So I eventually decided to get one of these jobbies from ebay

http://cgi.ebay.co.uk/DIGITAL-MOISTURE- ... 414ec13a18

can't go wrong really for that sum. Had a play with it today and all the internal wood was registering around 5/6%, a piece I picked up from Boddies today was 3/4% and some maple I had part machined yesterday and had spent all winter in the garage was showing 14%.

The percentages may or may not be accurate, what was important was that readings that should have been similar were and relatively there was a difference between the indoor and garage timber. It was enough to make me bring it indoors for some seasoning before final machining.

So far so good and I'll see how I get on with it. Worst comes to the worst, I can always rewire it, fit a bigger battery and Tazer my colleagues at work

 

[Racers]

Hi,

That looks good for the price, I might just treat my self to one.


Pete

 

[colinc]

you could always calibrate it if you are feeling like getting a bit scientific and can beg/borrow some accurate (calibrated?) scales.

What you do is weigh a sample of wood - something smallish and relatively thin and weigh it (W1). Take a reading with your meter. Then dry it (the wood not the meter) in a low oven at approx 100-110 degrees C and keep weighing it until the weight stays constant (Wc).

The original moisture content is ((W1-Wc)/Wc) x 100

Probably overkill, but that's the method described in BS2v37 for aircraft timber for proper aeroplanes.

Colin

 

[Ironballs]

Thanks Colin I'll bear that in mind

 

[Blister]

I've been after a decent moisture meter for a while and like Ed had my eye on an Electrophysics one, until they stopped selling them... Now being a bit tight I didn't fancy paying 100 plus quid for a bells and whistles one, especially as I don't need it to be that accurate and it won't get used all the time.

So I eventually decided to get one of these jobbies from ebay

http://cgi.ebay.co.uk/DIGITAL-MOISTURE- ... 414ec13a18

can't go wrong really for that sum. Had a play with it today and all the internal wood was registering around 5/6%, a piece I picked up from Boddies today was 3/4% and some maple I had part machined yesterday and had spent all winter in the garage was showing 14%.

The percentages may or may not be accurate, what was important was that readings that should have been similar were and relatively there was a difference between the indoor and garage timber. It was enough to make me bring it indoors for some seasoning before final machining.

So far so good and I'll see how I get on with it. Worst comes to the worst, I can always rewire it, fit a bigger battery and Tazer my colleagues at work

Hi , just read your post IB

you say you had readings of 3/4% on some wood , but on the ebay add it says " * Test Range: 5% to 40% " does it go below 5% as stated on ebay ?

Thanks

Allen

 

[grahamar]

Hi,

Just some thoughts that came to my mind when reading your post.

The meter is only measuring moisture at the point where the probe is in contact with the wood. By this I mean the inner part of the piece most likely will have a different moisture level than the outside.

On large(r) pieces this level can vary quite a bit. If you cut a log in half for example and then measure the ends that were exposed and compare to the centre you can often see a quite large difference in levels.

I have no idea how accurate my meter is ( the caibration tip is a really good one IMHO), but it's the relative difference in the number I'm looking at - rather than the number itself.

If I bring wood from outside to inside - I use the meter to check the moisture level is stable over the course of several days - or weeks if need be - rather than care to much about the value/number itself.

Graham

 

[squib]

I got this for christmas and its great, i only use it for comparitive readings as i stick it in some timber i know to be stable,

http://www.maplin.co.uk/Search.aspx?cri ... &source=15

 

[Ironballs]

Yes it does go outside the range specified, but then it starts at 0% so I guess has to go somewhere. I would imagine it's accuracy is decidedly average, but it's the realtive differences I'm looking for and it seems consistent there

 

[Tim Nott]

As you say can't go wrong at the price - what battery does it take ? Is it what we old-timers call a PP3?

Just about to have a major row with our timber supplier - 580€ worth of 'best joinery quality' 54mm thick oak which has a moisture content of 25 per bloody cent, going on the oven test.

 

[xc-mtbr]

i'm looking at getting a cheapie one too,

The 2 probes measure electrical resistance. One probe sends out a signal and the time it takes to get to the other probe is a measure of the resistance between the two this will take into account the water throughout the piece providing the voltage is sufficient, not just toward the ends where the probe meets.

Any other cheapie models anyone has bought and quite happy with ?

 

[Harbo]

I use a cheapo Axminster one - for comparison purposes to see when the wood has stopped drying out so not bothered about complete accuracy.


Rod

 

[davin]

I bought this one (Im sure that I only paid £20), gives you an idea of what the m/c is.


http://www.clasohlson.co.uk/Siteseeker/ ... ture+meter

 

[Qwibble]

I bought the very same model as Rimmer. The accuracy doesn't seem great (but then I've got nothing to compare it with). Overall for a few quid I guess it's a reasonable buy..

.. just as long as you don't design something to fly.