Basic Moisture Meter

[houtslager]

here is the url for those tempted link
and for the real curious here is what it looks like.I got the info
from a green forum , where someone uses it to check their fire
wood prior to moving into the house for their stove. I liked it so
much , I bought one.

Will do a review once I 've used it.

 

[mrbingley]

Cheers for the link.
Ordered one, I thought that, at that price maybe I should :wink:


Chris.

 

[lucky9cat]

Looking forward to the review. That could be a really useful tool!

Cheers, Ted

 

[promhandicam]

I had a certain sense of deja vu reading this. As I said in the previous thread, I found it very helpful to have a look at this website as on the third page their is a very useful table showing Moisture content (%) at various relative humidity values and temperatures. Without this information a moisture meter isn't much help as it is difficult to know what the correct moisture content should be for the given conditions. The only way to use it would be to measure a piece of wood that has already acclimatised to the environment that you want to work in, and customers might just get a bit anxious seeing you jamming 2 metal spikes into their furniture.

There is also a table showing the Fibre saturation point (FSP) for various timber. FSP is the moisture content at which all of the free water is removed - the cell cavities are empty - but the cell walls are still completely saturated. I think I'm right in saying that shrinkage only occurs when the MC is below the FSP. Take a look at the link - I think it is very helpful.

Steve
(where the Relative Humidity is about 99% tonight!) :shock:

 

[user 2070]

Amazing: Price is a huge contrast with something like the Wagner meters or even the more moderately priced pin based meter from Axminster (£70). I guess the big (open) question would be how accurate it can reliably be.
Simon

 

[mrbingley]

How would you tell the accuracy without buying one of the expensive ones to compare it with. Ain't got no friends with one ot those. In fact I don't know anyone with one of the expensive models.
Looks like I'm doomed

Chris.

 

[RogerS]

Amazing: Price is a huge contrast with something like the Wagner meters or even the more moderately priced pin based meter from Axminster (£70). I guess the big (open) question would be how accurate it can reliably be.
Simon

Measured some ash yesterday.

Cheapie moisture meter - 17%
Wagner moisture meter - 32% (probably higher as this is the upper range on the Wagner)

You pays your money......

 

[user 2070]

Roger,
Actually I should probably confess that I made my choice and paid my money some years ago for a Wagner which seems to give reasonable results.

However for Chris: The older method (described in Joyce) for determining moisture content (before electrical meters were deployed) was by weighing when wet, drying and re-weighing. The equipment used for drying was purpose built for the job, but I have done this with a conventional electric oven at ~105C and some digital kitchen scales (on scrap wood). I used scraps which were relatively small (~200g) and baked until the weight stopped changing when I tested - several hours altogether. The recommendation was 18 to 24 hours but my samples stopped changing before this time.

I think I recall someone once mentioning using a microwave oven for this, but I have a nasty feeling they also recounted the sample either burning or exploding - so I thought it prudent to avoid that route!

Simon