I agree with Leslie - the nice thing is most are good or better. If one 
is specific you could see how it is calibrated over a region

using a micrometer to test the calipers.  Once cleared for use it is 
good.  I have both plastic and several metal ones for the shop.

The plastic one stands nicely with the two metal ones.  Close enough for 
the caliper to be the measuring device.  e.g. one isn't trying to 
measure to the micron with a caliper.

Martin

On 4/30/2017 9:38 PM, Leslie Crnkovic wrote:
> Hello Jack,
>
> Personally I am a fan of digital calipers to measure shells (a micrometer is the wrong product to use).
> However I would suggest buying it  made form a composite or other non-metal material, which will be lighter weight, easier to handle, and less chance of damaging the shell.
> Depending on how picky you are in the level of accuracy, Harbor Freight sells one for about $10 bucks and 20% off coupons are easy to get.  Or you can go the other rout of high end and spend over $100 with products such as Mitutoyo Absolute Digimatic, or Starrett.
> At the college we use a blend of both ends of the quality spectrum.
>
> Leslie
>
> --------------------------------------------------------------------------
> From: Conchologists List [mailto:[log in to unmask]] On Behalf Of Jack Sullivan
> Sent: Sunday, April 30, 2017 9:04 PM
> To: [log in to unmask]
> Subject: [CONCH-L] Digital micrometer preferences
>
> While on vacation recently in the resort town of Rehoboth Beach, DE, I happened on a shell store. Half an hour later I had spent $36 on 18 or so on 18 or so nice cone shells, some known to me (marmoreus, textile, a couple of leopardus variants)  along with a number of smaller shells that will require identification using my library. Up to now I had been relying on sellers to let me know the shell lengths, but now I'm interested in picking up an inexpensive 6"-capacity micrometer with an LCD readout. I'd appreciate it if fellow shell collectors with first-hand experience with these devices would share their experiences and any reomendations. Thanks!
>
> Jack
>
> ----------------------------------------------------------------------
> [log in to unmask] - a forum for informal discussions on molluscs
> To leave this list, click on the following web link:
> http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
> Type your email address and name in the appropriate box and
> click leave the list.
> ----------------------------------------------------------------------
>

----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------