NUTS AND VOLTS

Posted in: Nuts and Volts

A Digital Salinometer

Believe it or not, Daniel Kramnik is only a Junior in High School and has built this Digital Salinometer for a Water Quality Science Olympiad event. The Digital Salinometer built by Daniel took almost 2 weeks and is capable of accuracy within 0.0014%. Daniel's entry ended up winning him first place at the regionals and he's now headed for the State competition in March. Amazing what high school kids can do these days!

"The entire circuit consisted of several parts: an opamp-based salinity-measuring circuit, a linear positive/negative power supply, a digital voltmeter, and a peltier device temperature controller.


In order to save time debugging (inevitably) flawed bread or perfboarded circuits, I designed custom circuit boards in Eagle CAD and etched them at home with ferric chloride. I won’t post my .sch/.brd files as that would make it too easy to copy this project for Science Olympiad, but I will share schematic image files and board image files (if you already know how to reCAD them for etching in Eagle, chances are, you’re already beyond this guide)."

 


[Source] HackedGadgets via A Digital Salinometer


Comments

  • submit question
  • reader feedback
  • submit ideas

Projects:

  • USB, LEDs, and Some Sensors

    Turning LEDs on and off is fun and all, but why not add a sensor or two that would be useful for something other than the usual light show? Read More...

  • The Versatile Wireless Doorbell

    Advances in technology often decrease price points, but not usefulness. See how to turn one circuit into several devices that most homeowners would find invaluable. Read More...

  • Frequency Counters and Retrofitting

    Even the lowest grade frequency counters are often the most accurate instruments on the test bench. This article will describe their general principle operation, but more specifically on the construction and retrofitting into existing equipment such as the sweep generator and RF signal generator covered in recent issues. Plus, we'll take a look at expanding added features, all the way to a full blown universal counter. Read More...