There is a "Hand-Held, Portable, Hardness Tester"
commonly used in the fibreglass composites industry.
Putting "barcol hardness"
into http://www.google.com returned 2,170 links!
We use the Barber-Colman version
http://www.ciicontrols.com/library/impressor/barcol.htm
It "weighs only 1 lb. 2 oz. and comes complete with carrying case,
adjusting wrench and two spare indenter points, 2 lb. 8oz".
Do note that you need to practice using it for a while
before you get reasonable repeatability in the numbers returned!
===================================
Dr John Summerscales
Reader in Composites Engineering
===================================
Advanced Composites Manufacturing Centre
Department of Mechanical and Marine Engineering,
Smeaton Building Room 101
University of Plymouth
Plymouth, Devon UK, PL4 8AA.
Telephone: +44.1752.23.2650
Facsimile: +44.1752.23.2650
WebSite: http://www.tech.plym.ac.uk/sme/jsinfo.htm
===================================
-----Original Message-----
From: Peter Keen [mailto:[log in to unmask]]
Sent: 26 February 2003 21:05
To: [log in to unmask]
Subject: Determining hardness of zooplankton integument
Hello,
I've had an inquiry from a doctoral student who wishes to determine the
hardness, relative or otherwise, of the integument of zooplankton that form
the natural prey of crayfish phyllosoma. She originally proposed using a
penetrometer but the ones available to her were far too large and it's my
feeling that they all will be given the scale of her test subjects which
range from a few millimetres to a couple of centimetres. We've considered a
surface hardness instrument such as used for testing metal surface coatings
but she was concerned that the storage of samples until returning from her
sample collection cruise would affect the properties of the integument, and
the instruments available to her cannot be taken on board the ship for
testing while fresh. Another suggestion was to treat sorted samples in bulk
and dissolve the calcium carbonate fraction away with EDTA to ascertain the
% compostion ratio by weight which may be useful for the crustaceans but
perhaps not for other species. Prey species include copepods, salps, and
fish larvae. I'd appreciate any ideas anyone might have on this topic that
we could explore prior to her departure on the sample collection cruise in
mid-march. I look forward to responses with interest.
Best Regards
Peter Keen
University of Auckland,
School of Geography and Environmental Sciences
Phone: 09 3737 599 ext 88536
e-mail: [log in to unmask]
http://www.auckland.ac.nz
Best Regards
Peter Keen
University of Auckland,
SGES
Phone: 09 3737 599 ext 8536
e-mail: [log in to unmask]
http://www.auckland.ac.nz
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