From: nze christian (christian_nze@hotmail.com)
Date: 02/07/01-03:00:31 PM Z
Sure jeffrey. it is why I wrote it is appoximative. As volume depend on
temp, and density of the liquid. But Alt print work without being so
precise. It can take a little variation.
christian nze
>From: "Jeffrey D. Mathias" <jeffrey.d.mathias@worldnet.att.net>
>Reply-To: alt-photo-process-l@sask.usask.ca
>To: alt-photo-process-l@sask.usask.ca
>Subject: Re: pipette dreams
>Date: Wed, 07 Feb 2001 15:49:04 -0500
>
>Nick Makris wrote:
> > ... do you have the relationship of drops to
> > millileters or stated differently, how do you determine the correct
>amount
> > of fluid to be dispensed.
>
>No. Nze stated the .05 ml per drop, but that may work for water at
>standard conditions and is a good estimate. However, I have measured
>different drop sizes depending on the dropper and the solution (likely
>due to differing surface tension interactions). Anyway I have found it
>best to calibrate each dropper for each solution. Now this is not a
>problem if the threshold amount of all solutions are well exceeded; some
>wide tolerance can still work, but at the expense of wasting chemistry.
>
>The best accountability is to measure volume in ml and not drops.
>
> > ... It could be that the best way to determine where to
> > make the mark on the dropper would be to take the dropper that you use
> > successfully and drop drops into the 'to be marked' dropper. ...
>
>That could certainly work. But again I caution that different solutions
>may have a different number of drops per ml. So it is best to calibrate
>to make sure the different solutions are measured accurately relative to
>each other. In other words, calibrate all droppers with drops of the
>same solution from the same dropper. The 1 ml syringes, accurate to .01
>ml can be found at most drug stores and are inexpensive (and only one is
>required).
>
>--
>Jeffrey D. Mathias
>http://home.att.net/~jeffrey.d.mathias/
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