[NHCOLL-L:3875] RE: Monitoring alcohol concentrations in spirit collections

[Robert Waller]

Hi Lisa,
As you suggest these seem a great idea in theory.  The problem for me is that I am not aware of any testing by an independent lab to determine how reliable they are.  These rely on a known mixture of plastic and inert filler, with no entrapped air bubbles, to have the correct density.  I will want to see the results of sampling and testing by an independent laboratory (e.g., ICN, CCI, CMN, MCI) to determine the range of densities random samples of indicator exhibits.  Without such verification, I would not recommend their use.  I hope Labshop will arrange for the testing that could make this product valuable to many of us.
Rob

Robert Waller, Ph.D.
Chief, Conservation
Chef de conservation 
Musée canadien de la nature/Canadian Museum of Nature
C.P. 3443, Succ. D              /P.O. Box 3443, Stn D
Ottawa, ON
K1P 1P4 
Tel.:  (613)566-4797
Fax:  (613)364-4027
rwaller at mus-nature.ca

-----Original Message-----
From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of Lisa Conyers
Sent: June 10, 2008 10:04 AM
To: NHCOLL-L
Subject: [NHCOLL-L:3873] Monitoring alcohol concentrations in spirit collections

Hi there

I was just wondering if anybody has experience using the Concentration 
Shift Indicators supplied by Labshop in The Netherlands?
Basically they are two plastic 'pills' which you place in a specimen jar 
and they either float or sink depending upon the concentration of 
ethanol/industrial methylated spirit  present. They are intended to give 
a rough estimation of alcohol concentrations, removing the need to open 
the jars to test with a density meter (unless more accurate measurements 
are required) - which obviously would be ideal with thousands of jars to 
monitor. I think they sound great in theory but it would be nice to know 
if anybody has encountered any problems. If you have used them and not 
had any problems it would also be nice to know!

Many Thanks

Lisa Conyers

-- 
Lisa Conyers
Zoological Collections Technician (Invertebrates)
Oxford University Museum of Natural History
Parks Road
Oxford OX1 3PW

T 01865 272581/272950
F 01865 272970
E lisa.conyers at oum.ox.ac.uk