My coach says that we don't need one (which we didn't). They were too expensive to buy and too confusing to make.witwi465 wrote:One of the items on the list of students to bring to the competition is a 9-volt conductivity tester. I have looked it up on Amazon and it costs over $200. I will leave the link below. Is there an alternate item or a low cost one, or did I just view the wrong conductivity tester?
https://www.amazon.com/Extech-Conductiv ... B0137IN21A
Exp Des, Wind, Food, and Bottle
So far, we haven't used oneSkink wrote:It's an artifact from the Powder event rules. That said, they're in the rules, so competitive teams will bring them. Fortunately, they take minimal effort (or know-how) to home-make; there are instructions either on this or the National site.
I suppose, if you want to take the time to make one, you can, but my team decided not to.Exp Des, Wind, Food, and Bottle
There is no need to invest that kind of money. Here is one from Carolina for $28.00 that will do everything needed for this event.:witwi465 wrote:One of the items on the list of students to bring to the competition is a 9-volt conductivity tester. I have looked it up on Amazon and it costs over $200. I will leave the link below. Is there an alternate item or a low cost one, or did I just view the wrong conductivity tester?
https://www.amazon.com/Extech-Conductiv ... B0137IN21A
Thank you! I will ask my coach for thisdholdgreve wrote:There is no need to invest that kind of money. Here is one from Carolina for $28.00 that will do everything needed for this event.:witwi465 wrote:One of the items on the list of students to bring to the competition is a 9-volt conductivity tester. I have looked it up on Amazon and it costs over $200. I will leave the link below. Is there an alternate item or a low cost one, or did I just view the wrong conductivity tester?
https://www.amazon.com/Extech-Conductiv ... B0137IN21A
http://www.carolina.com/catalog/detail. ... AlhN8P8HAQ
We ran this event a few weeks ago and had a station where we asked the kids to put 4 soups in order from least saline to most saline. A device like this would perform admirably.
Exp Des, Wind, Food, and Bottle
it's really just up to the event coordinator. I think it would be in their best interest to test that and ensure the competitors have a good knowledge of the tests, but it's just an option that they can choose to take.Sasstiel wrote:In the last meet I attended, there was no "lab work" with Benedict', Biurets, etc. Any ideas why?
I agree the powerpoint is not very clear with the calculations for calibrating the device and for using it in testing. It is probably clear to those with good understanding of the concepts, but for many of us, like me, we are left scratching our heads.Sasstiel wrote:I would suggest not using that; the rules call for joules/gram. However, if you want to find calories, here's the equation I use...cwscio wrote:Has anyone evaluated the equations found in the 2017 power point on Soinc.org/food science?
I have asked a chemical engineer to assist us with the equations. He looked at the power point and shook his head at the manner in which it was written.
Q=m*c*ΔT. Q is the number of calories, m is the measurement of water (in grams, 1 mL = 1 gram), c is this equation: 1 calorie/gram*degree Celsius, and ΔT is the temperature of the water before burning subtracted by the temperature of the regular water (this is in degrees Celsius) (for example, 40-32=8).
If you want to convert calories to calories/gram, find the mass of the food before burning and divide the calories (what you just got) by that mass. Also, 1 cal/g = 4.1868 Joules/g.
