Proposal for Summer 2005

TURBIDITY METER EXECUTIVE SUMMARY James A. Berg [email protected] (510) 910-3831

Purpose The purpose of this research project is to develop a turbidity meter that is cost effective for small cities in the developing world. Turbidity meters are necessary for determining how much alum to add to remove sediment in the water. It is not necessary for water purification plants in the developing world to have turbidity meters that meet EPA standards. Existing devices are expensive, at least $600, and exceed the requirements of a city in the developing world. For example the ESW group working on the water purification plant in Honduras had to find a turbidity meter and eventually got Cornell to donate the Hach 2100P which costs $800 new. Developing a meter that is functional for the developing world and costs as little as possible will make water purification accessible to more cities.

Current Development Status At present the low-cost turbidity meter is in development and is functioning fairly closely to the values measured in the lab. Though the measured value (value from the Hach 2100 in the lab) and the calculate value (value from the experimental meter) can differ by as much as 55 Nephelometric Turbidity Units (NTU) the average difference is only 18 NTU. The electronic components in the meter add up to about $60, this means that with the additional costs of the plastic frame and sample containers the meter should retail for $100 to $150.

Summer Goals The goals for this summer are to refine the meter to a precision of 0.1 NTU between 0 and 50 NTU and a precision of 1 NTU between 50 and 1000 NTU. Once the meter meets these minimum requirements we will have to prototype the circuitry and plastic frame as well as find funding sources and a distribution network. After the prototype is finished we will need to find a manufacturer for both the plastic frame and the circuitry. The funding that will be necessary for refining and prototyping the meter is rather hard to estimate. We will be experimenting with the light source, light sensors, amplifiers, and possibly the micro controller. Though the ECE lab will grant us access to some of this equipment, the light sensors and light source are not standard and we don't know how many different types we will need to try. Also once we get into prototyping it can cost quite a bit to print the circuit board. I estimate that development will at most cost around $500, however prototyping could cost $1000 to $1500 more.

After the Summer Once we have developed a finished product we can concentrate on how best to bring it to customers. There are a several possibilities at this point. This could be th beginning of a company that sells inexpensive water purification tools in the developing world. Another option would be to license the turbidity meter out to an existing company like Approtech that already has manufacturing and distribution networks in the developing world.