Heidi Rausch's Individual Contribution Page

Summer 2011

I was a member of the Turbidimeter Team. This team worked to create a low cost turbidimeter prototype to be used by communities in Honduras. At the end of the summer we were able to ship ten turbidimeters to Hondorus; the design only cost about $4. This design consisted of a plastic stick about 60 cm long to which was attached a LED light and a HDPE block with a simple design stuck to top of it. This design could read NTU values down to 15 NTU; in the future hopefully a turbidimeter that can read NTU values down to 5 NTU or lower can be created.

Fall 2011

I am a member of the Turbidimeter team as well as the Inlet Manifold Fabrication Team. This semester on the Turbidimeter team worked to make the turbidimeter more accurate. We tried to do this by experimenting with different colored LED lights and different sizes of HDPE blocks. At the end of the semester we were able to come up with a design that can possibly read down to about 7 NTU while still being only 60 cm long. However, this design needs to be tested more for accuracy before it can be used. Also, the team has concluded that it may impossible to get any lower read any lower NTU without lengthening the plastic stick that is the turbidimeter lowering rod.
On the inlet manifold team we worked to create a suitable method for creating the inlet manifold diffuser tubes that have been designed for the plant. The main problem that need to solved was that a fabrication method needed to be established for changing the shape of the diffuser tubes (PVC pipe) from a circle into a rectangle. The final method that the team came up for creating this rectangular geometry was heating the PVC pipe in boiling water over a hot plate and then forcing the hot PVC over a metal mold that had also been heated in the boiling water.