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 Subject: weights & measurements Category: Science Asked by: chigung-ga List Price: \$2.50 Posted: 13 Sep 2004 11:20 PDT Expires: 13 Oct 2004 11:20 PDT Question ID: 400625
 `How many drops of water are in one gallon of water?`
 There is no answer at this time.

 Subject: Re: weights & measurements From: rainbow-ga on 13 Sep 2004 11:41 PDT
 ```Hi chigung, Since I cannot verify the following calculations to be accurate, I'm posting these as a comment. If you find this information to suffice, let me know and I will post it as an answer. "Have students predict how many drops of water they can put in one tablespoon. Provide them with eyedroppers, standard measuring tablespoons and water. Have students keep track of the number of drops of water they successfully drop in until the tablespoon no longer holds anymore. (Aproximately 500 drops of water will fill one tablespoon) The following chart was used to figure the amount of atrazine allowed in drinking water: 500 drops water in one tablespoon 8000 drops water in one cup 16,000 drops water in one pint 128,000 drops water in one gallon 640,000 drops water in five gallons 12,800,000 drops water in 100 gallons 128,000,000 drops water in 1000 gallons 1, 280,000,000 drops water in 10, 000 gallons" Fort Hays State University http://www.fhsu.edu/kga/lp/6/mcchesney.html "Let's say that you have a moisture detector in your basement sump area that's so sensitive that it will respond to one drop of water in the sump. You want to know right away 'cuz you've got valuable furniture in your basement. This then becomes your standard - one drop of water. Now you have some ground water seep in. An ounce (100 drops, a quart (3200 drops and finally a full gallon of water(128,000 drops)." Greenspun http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=0016AO I hope that helps. Best regards, Rainbow```
 Subject: Re: weights & measurements From: pinkfreud-ga on 13 Sep 2004 11:46 PDT
 ```This may help: http://www.versaquatics.com/Measurement%20Conversion.htm```
 Subject: Re: weights & measurements From: guzzi-ga on 13 Sep 2004 17:11 PDT
 ```There is unfortunately no definitive answer to your question. Industrially I had a similar requirement when we were trying to meter exact quantities of an adhesive. Not really surprisingly, the volume of the drop (ie when it detached) was very dependent upon orifice size, orifice shape, thickness of tube end, and material of the dispenser. I seem to recall that our extremes were 5:1. Water may be even more problematic because of it?s polar nature, hence wetting ability. The purity can also make a great difference as too will temperature -- the sound of hot water is different to that of cold due to fluidity. All that can be said is that using deionised water at a constant temperature with the same dropper rate and the same dropper in still air, will give you reasonably consistent drop size. Only then can your question be answered. However, one could experiment with extremes and say that the number of drops will be between two figures. One final variation -- US gallons are smaller than real gallons (ie UK). Best```
 Subject: Re: weights & measurements From: pinkfreud-ga on 13 Sep 2004 17:17 PDT
 ```Guzzi, Regarding the "reality" of our gallons, I don't think it matters a hoot in a rainbarrel, since "real" scientists use the metric system. ;-) ~Pink```
 Subject: Re: weights & measurements From: tornado2-ga on 18 Sep 2004 19:16 PDT
 ```I just counted, using a water dropper and an OXO measuring cup, that one half an ounce of water (or one tablespoon) is 261 drops. This would be 522 drops for one once. A gallon is 128 ounces, so 128ounces/gallonx522drops=66,816 drops/gallon. Note: the size of a drop of water varies greatly depending on the size of the hole that produced it and the force behind it. So, I do not think you will get a definitive answer. Perhaps my drops were just larger than those that rainbow's article used and so there are fewer per gallon.```
 Subject: Re: weights & measurements From: willh-ga on 25 Sep 2004 16:18 PDT
 ```"Drop" is not a unit of measure. Will```
 Subject: Re: weights & measurements From: tutuzdad-ga on 25 Sep 2004 17:10 PDT
 ```The answer, of course, is ONE. tutuzdad-ga```
 Subject: Re: weights & measurements From: tutuzdad-ga on 25 Sep 2004 17:14 PDT
 ```Let me clarify...A drop of water has no standard unit of measure. There is ONE big drop of water in a gallon container of water. Your question is like asking "How many peices of ice are in a glacier?". The answer is ONE - it's just a really, really big one. tutuzdad-ga```
 Subject: Re: weights & measurements From: armydoc-ga on 30 Sep 2004 14:18 PDT
 ```As stated previously, there is no one answer, because drops of water may have different volumes. In medicine, IV sets are calibrated as "drops per milliliter", or the number of drops through the set that will deliver 1 mL. Pediatric sets may have as many as 70+ drops per mL, and veterinary large animal sets 15 drops per mL. FYI, while a drop is not a unit of measure, it does have a latin-derived abbreviation: gtt, for gutta (pl. guttae) meaning "drop". Therefore, IV sets are often compared by "gtt/mL".```
 Subject: Re: weights & measurements From: willh-ga on 05 Oct 2004 08:42 PDT
 `yada yada. . . while a drop is not a unit of measure. . . yada yda`
 Subject: Re: weights & measurements From: subcodex-ga on 23 Oct 2004 22:11 PDT
 ```The key to the answer is knowing the unit of measurement of a "drop". This unit is the "minim". There are in a U.S. gallon 61,440 minims [drops]. The British gallon, larger than the U.S. gallon, contains 76,800 minims [drops]. Drops vary in size and amount. But the quantity of the "minim" always remains the same, this size being an agreed upon standard measure of volume and capacity.```