[Nhcoll-l] Digital density meter vs refractometer

[Callomon,Paul]

I'd also point to the good old Traille glass densitometers - the bigger ones are pretty accurate, though you need enough fluid for them to float in. The little "pocket" ones are less precise, but are cheap and do not go out of calibration.


Paul Callomon
Collection Manager, Malacology and General Invertebrates
________________________________
Academy of Natural Sciences of Drexel University, Philadelphia
callomon at ansp.org Tel 215-405-5096 - Fax 215-299-1170
________________________________
From: Nhcoll-l <nhcoll-l-bounces at mailman.yale.edu> on behalf of Bentley, Andrew Charles <abentley at ku.edu>
Sent: Tuesday, March 21, 2023 5:11 PM
To: nhcoll-l at mailman.yale.edu <nhcoll-l at mailman.yale.edu>
Subject: [Nhcoll-l] Digital density meter vs refractometer


External.

After receiving an enquiry from someone about cheap alternatives to expensive digital density meters, I purchased a refractometer from Amazon for $22  (https://www.amazon.com/dp/B018LSMI34<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB018LSMI34&data=05%7C01%7Cprc44%40drexel.edu%7Cb87a66f4bdba443f856808db2a50e0e6%7C3664e6fa47bd45a696708c4f080f8ca6%7C0%7C0%7C638150299084791886%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CijD0jCBSRBmMJsPoEiSY%2Bw9XytR%2BXqlsYcrB%2BOR0CU%3D&reserved=0>).  I did a number of tests against 70%, 50% and 30% and various concentrations in between measured with our $3,000 Anton Paar DMA 35 digital density meter.  The refractometer is not super accurate but is probably within 2-3% once calibrated.  I first calibrated against distilled water using the method in the instructions but found that it was reading a little high and so then calibrated against a known 70% concentration and then it was reading a little more accurately.  Take home I think is that if you are not too concerned about super accurate readings and just want to get in the ballpark it is a viable, cheap (can’t beat $22) alternative to a digital density meter.



Just an FYI for those working with wet collections who may be working with restrictive budgets.



Andy

    A  :             A  :             A  :
 }<(((_°>.,.,.,.}<(((_°>.,.,.,.}<)))_°>
    V                V                V
Andy Bentley
Ichthyology Collection Manager
University of Kansas
Biodiversity Institute

Dyche Hall
1345 Jayhawk Boulevard
Lawrence, KS, 66045-7561
USA

Tel: (785) 864-3863<tel:%28785%29%20864-3863>
Fax: (785) 864-5335<tel:%28785%29%20864-5335>
Email: abentley at ku.edu<mailto:abentley at ku.edu>

ORCID: https://orcid.org/0000-0002-3093-1258<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Forcid.org%2F0000-0002-3093-1258&data=05%7C01%7Cprc44%40drexel.edu%7Cb87a66f4bdba443f856808db2a50e0e6%7C3664e6fa47bd45a696708c4f080f8ca6%7C0%7C0%7C638150299084791886%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=fxy8AKRyYn5m576PG84ddCBzSRdBTK6CIXfz6CloWzg%3D&reserved=0>

http://ichthyology.biodiversity.ku.edu<https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fichthyology.biodiversity.ku.edu%2F&data=05%7C01%7Cprc44%40drexel.edu%7Cb87a66f4bdba443f856808db2a50e0e6%7C3664e6fa47bd45a696708c4f080f8ca6%7C0%7C0%7C638150299084791886%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=UpXiVUCnUV0oZMCGuD21ZUQLDuQqpBqGvNtLJZLjsyc%3D&reserved=0>

    A  :             A  :             A  :
 }<(((_°>.,.,.,.}<(((_°>.,.,.,.}<)))_°>
    V                V                V


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20230321/14b66770/attachment.html>