From: Nick Makris (nick@mcn.org)
Date: 02/07/01-12:23:13 PM Z
Jeffrey, Great idea. Question - do you have the relationship of drops to
millileters or stated differently, how do you determine the correct amount
of fluid to be dispensed.
Everyone starts with drops and one could use a known dropper as the
calibrated measure. 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. Just a
thought.
Nick
----- Original Message -----
From: "Jeffrey D. Mathias" <jeffrey.d.mathias@worldnet.att.net>
To: "alt-photo-process list" <alt-photo-process-l@usask.ca>
> Here's a way to turn an inexpensive dropper into an accurate pipette for
> measuring out coating solutions.
>
> This works best for glass droppers and may be more accurate than using
> plastic.
>
> Materials:
> + droppers
> + a small calibrated syringe (1 ml, accurate to .01 ml, most drug stores
> have these)
> + masking tape
> + chemical resistant white epoxy paint
> + distilled water
>
> Instructions to calibrate:
> + determine the amount required to be dispensed
> + fill syringe to desired amount with distilled water (distilled is used
> so as not to contaminate the dropper.)
> + remove bulb from dropper
> + placing finger over narrow end of dropper and holding with large end
> up, fill with measured syringe contents
> + place masking tape on dropper so that edge is at the level of the
> water and the tape covers the water filled portion.
> + release water from dropper
> + mark a line on the dropper at the tape edge using the epoxy paint
> + remove tape and let paint dry
>
> Instructions to Use:
> + fill dropper with solution to just above paint line
> + then empty some solution back so that the top of the solution is at
> the top of the paint line
> + empty entire dropper into destination
>
> The delivery might be slightly less due to solution sticking to the
> dropper surface, but should be very consistent.
>
> Each dropper has been marked to deliver the precise desired amount of
> solution. A dropper could even have several marks.
>
> --
> Jeffrey D. Mathias
> http://home.att.net/~jeffrey.d.mathias/
>
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