[Gasification] Better than Spit Moisture Meter

[jim mason]

the cheap moisture meters are also available on ebay and via amazon.
search "moisture meter" many in the 30 dollars and under for pin
types.  50 or so will do an inductive type.  combinations of the two
are findable on ebay for around 100.

glad to hear the tests showed the cheapies to be at least tolerable
for ballpark.

with the pin types, remember to cut the block apart so you can test at
different depths other than the 1/4" pin.




On Wed, Feb 27, 2008 at 4:58 AM, Thomas Reed <tombreed at comcast.net> wrote:
> Dear Friends of Biomass/wood:
>
>  Biomass has many excellent fuel properties - renewable, carbon neutral,
>  low cost - but one problem is that it is by its nature highly absorbing
>  for water.  Live biomass typically contains 50% moisture by weight AND,
>  you can't look at a piece of wood and judge its water content.   It will
>  dry relatively easily to 20% moisture in any climate, but only in Denver
>  here do we enjoy 7% "Denver dry" wood.
>
>  The founder of the Biomass Energy Foundation, Harry LaFontaine, tells
>  that at the beginning of WWII he and Niels Bohr developed wood gasifiers
>  when the Nazis took over all liquid fuels.  They set up a supply system
>  of bags of wood blocks (usually Beech), match box size, that had to have
>  less than 20% moisture by weight and they had uniformed inspectors who
>  went to the stores to make test the water content by weighing, then
>  heating to 110C and weighing again.
>
>  Halfway through WWII someone developed a simple "spit" test.  If you
>  spit on one end of the wood block and could blow bubbles from the other
>  end it was <20% MC.  The testing police disappeared overnight.
>  ------------------------------------------------------------------------
>  Today we like more quantitative results and don't spit in public.
>  Yesterday I was overjoyed to find a two pin Moisture Meter for wood at
>  Harbor Freight, about 2"X6"X1", with a nice leather case.  It is made by
>  Cen-Tech, uses a 9 V battery (included) and costs ~$14.
>  (http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=96472)
>  It has a low (0-17%) and high (17-35%) range.  I haven't tested it
>  quantitatively yet, but one  of my very dry (EdBurtonCompany) Chunkettes
>  measured less than 7%.  I wetted it and it read 16%.  I'll equilibrate
>  some bone dry wood and test it quantitatively.
>  ------------------------------------------------------------------------
>  Dry wood is not always best.  In some cases wood with 10-15% moisture
>  burns more efficiently than bone dry wood because the flame zone is
>  localized, rather than allowing the whole log to evolve volatiles faster
>  than air can mix and burn.  (Measured by Tom Miles's nephew.)
>
>  Onward...
>
>  TOM REED               BEF/BEC
>
>
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>  http://info.bioenergylists.org
>



-- 
--------------------------------------------------------------------------------
jim mason
website: www.whatiamupto.com
current project: mechabolic (http://www.mechabolic.org)
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