From: Jeffrey D. Mathias (jeffrey.d.mathias@worldnet.att.net)
Date: 02/07/01-10:30:57 PM Z
Judy Seigel wrote:
> ... I am totally confused as to
> meaning of this thread.
I thought it would be helpful to pass on information for others
benefit. Most alt-photogrphers have and use dropper bottles for
solutions. Most want to budget their finances wisely. So this
presented a low budget, accurate, simple improvement with readily
available materials.
The calibrated syringe can easily be found at CVS or other common drug
stores (the needles are not needed). And only one is required.
> ... Now tell
> me again, why can't we just count drops?
You can. But for more accuracy consider that different liquids and
different droppers may form different size drops. So even if using
consistent plastic droppers, different liquids may still form different
size drops. This can result in an incorrect measuring of one substance
relative to another. It is common that the relative proportion of
solutions is more important than the absolute amount as long as the
amount is above the threshold.
The reason I suggested glass instead of plastic is that the epoxy paint
should stick to the glass better.
The reason I suggested epoxy paint is that solutions such as ferric
oxalate have a very low pH. Of course one could use a different cap for
the bottle and not leave the dropper in it, and this may be preferred
for long storage as there will be less chance of the rubber bulb being
damaged (especially with oxidizers [contrast agents] and strong acids).
I have found it more efficient to leave the droppers in the bottles and
just replace the bulbs when damaged.
-- Jeffrey D. Mathias http://home.att.net/~jeffrey.d.mathias/
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