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Re: Water Quality B/C
Posted: November 4th, 2013, 3:34 pm
by TwelveSquared
caseyotis wrote:TwelveSquared wrote:
We haven't actually built the device yet, but i will once we do.
The build is, as stated above, pretty simple- some sort of multimeter/ohmmeter/something-that-measures-electrical-resistance device, and a small apparatus that contains two metal leads of a particular size and distance apart(it doesn't matter, so long as the resistance will be within your device's measurable range)that are connected to the device. Then, you would just dip the leads into the sample, and plug the reading into a formula. We aren't the first people to try this, so you should be able to find plans or similar online. That's where we got the idea in the first place, actually.
Oh, okay.
Really? Odd. I looked up stuff like that online, and I couldn't find anything. I'm actually not that good at science, so that doesn't seem all that simple. But I'm sure I could make something like that with assistance.
This should be a good place to start-
http://mathinscience.info/public/home_m ... tmeter.doc. start with that, but find a way to fix the two leads a certain distance apart, then test a bunch of samples with different salinity. that should allow you to determine the correlation between your reading and the salinity, and you've got a salinometer.
Re: Water Quality B/C
Posted: November 4th, 2013, 4:31 pm
by caseyotis
TwelveSquared wrote:caseyotis wrote:TwelveSquared wrote:
We haven't actually built the device yet, but i will once we do.
The build is, as stated above, pretty simple- some sort of multimeter/ohmmeter/something-that-measures-electrical-resistance device, and a small apparatus that contains two metal leads of a particular size and distance apart(it doesn't matter, so long as the resistance will be within your device's measurable range)that are connected to the device. Then, you would just dip the leads into the sample, and plug the reading into a formula. We aren't the first people to try this, so you should be able to find plans or similar online. That's where we got the idea in the first place, actually.
Oh, okay.
Really? Odd. I looked up stuff like that online, and I couldn't find anything. I'm actually not that good at science, so that doesn't seem all that simple. But I'm sure I could make something like that with assistance.
This should be a good place to start-
http://mathinscience.info/public/home_m ... tmeter.doc. start with that, but find a way to fix the two leads a certain distance apart, then test a bunch of samples with different salinity. that should allow you to determine the correlation between your reading and the salinity, and you've got a salinometer.
Oh! Thank you so much~
Re: Water Quality B/C
Posted: November 4th, 2013, 5:53 pm
by mnstrviola
Je suis K wrote:Does anyone have advice on how to make the salinometer? How should I measure the salt and water mixtures?
To answer both your questions, check this link out!
http://soinc.org/sites/default/files/up ... er12_0.pdf
^ I definitely recommend using the above design, as it's a lot easier to build and calibrate. Go for using a thing straw, as that will help make measurements more precise.
Re: Water Quality B/C
Posted: November 17th, 2013, 5:07 pm
by Godlike
What does the Fleshy Algae look like? Google Images doesn't pull up any useful images...
Re: Water Quality B/C
Posted: November 21st, 2013, 3:46 pm
by Kazen
Godlike wrote:What does the Fleshy Algae look like? Google Images doesn't pull up any useful images...
I think it's seaweed, but I'm not sure.
Do we only have to identify organisms on the list given in the rules or do we also have to know others? Since in the rules they put IDing and regarding the table into two separate sentences.
Re: Water Quality B/C
Posted: November 24th, 2013, 12:05 pm
by CulturallyScientific
Technically, identification is not supposed to go beyond the organisms listed in the table in the rules, but I've seen several tests where they've asked for ID of other organisms...
Re: Water Quality B/C
Posted: November 29th, 2013, 8:30 pm
by geminicross
Can someone here explain BOD in a straightforward way? Thanks
Re: Water Quality B/C
Posted: November 29th, 2013, 9:04 pm
by caseyotis
geminicross wrote:Can someone here explain BOD in a straightforward way? Thanks
The wiki entry does a pretty good job of explaining.
So decomposers need oxygen to break down organic material. Biological oxygen demand is the amount of dissolved oxygen that the organisms in a certain amount of water, at a certain temperature, need in order to break down the organic material that's in that certain water sample.
It's important because this microbial metabolism (the breakdown of organic material by the decomposers for food) often depletes the oxygen in the water faster than it can be replenished. Organisms that are less tolerant of low oxygen levels can die off.
Re: Water Quality B/C
Posted: November 30th, 2013, 10:05 am
by rtunnel97
geminicross wrote:Can someone here explain BOD in a straightforward way? Thanks
BOD is, in simple terms, the amount of oxygen needed by the organisms in an ecosystem to live. The demand can basically met or not.
Re: Water Quality B/C
Posted: December 2nd, 2013, 9:43 pm
by PicturePerfect
Is there not a 2014 wiki for this event yet? Because this year it's about 'marine, coral reefs, and estuaries', and the wiki still shows last year's.