1. Abhijeet Kher Aakant Taurani Course: Embedded Systems and Software 55:032 Instructor: Dr. Anton Kruger

2. Particles can be suspended in water Test for water quality Clear water is not always clean water Drinking dirty water can cause many GI and other health problems Especially a problem in developing nations Why is measuring water turbidity important?

3. Cost ~$60!!! Source: http://www.nextag.com/turbidity-meter/shop-htmlhttp://www.nextag.com/turbidity-meter/shop-html Our Project

4. Components of Our Turbidity Meter Phototransistors LED Vial Slot Microcontroller LCD

5. Circuit Schematic Voltage Ratio Vs NTU Rating Transistor 2 Transistor 1 100k 470 Ohms LCD

6. Voltage Ratio & NTU Correlation  Higher the Voltage ratio, lower the NTU  Using the polynomial equation in the graph, we can obtain the corresponding NTU rating MS Excel plot of Voltage Ratio Vs. NTU Rating  Significant error +/- 5 NTU

7. How it works: Vial Inserted LED Emits Light Through Sample or Gets Refracted Phototransistors Pick Up Photons Signal Converted to Voltage Calculate Voltage Ratio and Respective NTU Rating Output Voltage Ratio and NTU Rating to LCD Screen

8. Possible Improvements Building a more compact container Fixing/mounting LED and Transistors firmly to prevent shock damage Error correction to provide a more accurate reading of voltage ratio Using a custom made circuit to cut down costs further Increase accuracy by using more test samples

9. Demo

10. Questions?