DESIGN OF A HIGH PRESSURE OPTICAL CELL FOR
IMAGING AQUEOUS SOLUTIONS IN MICROSCOPY

Project Sponsor: Dr. Greg Ziegler, PSU Food Science Dept.

Team Members: Stacy Shadel, Garrett Ferris, Zack Christman, Noel Maestre, Ray Gongaware

Faculty Coach: Dr. Savas Yavuzkurt

Spring 2006

Objectives                                    Dimensions and Materials                                   Temperature Control

Executive Summary:

The Food Science department has a need for an optical cell which will withstand temperatures of 200 °C and 250psia. There are commercially available optical cells, however they are costly and not within the scope of what is needed. Therefore it was decided to design an optical cell to accomplish these needs. The cell will be used for imaging starches crystallize under a variety of conditions and temperature changes.
The cell is designed to meet a variety of specific conditions. These include the ability to change the imaging distance between the glass plates to allow variable viewing between 10 micron and 0.5 mm, an integrated temperature variation control system up to 50°C/min. The variable viewing distance is changed using feeler gauge material as washers in variety of thicknesses, and the temperature is controlled using a calibrated thermocouple in conjunction with a Labview program with resistance heaters and a cold water flow rate for temperature control.
The cell itself will use a circular designed screw method with a viewing port of 0.5 inch in diameter. The optical glass will be a one sided highly polished to ensure a flat area with a diameter of 1 inch for use with sealing. Quartz will be the glass material because of its low thermal expansion coefficient and high durability. The threading will be 12 threads/inch acme threading to withhold the 250psia requirement. All of the seals will be made using Teflon ® material for its high temperature abilities and water sealing excellence.
The heating and cooling will be controlled using Labview. The cell will require an 85 watt heating band. The cooling will be done using tap water circulated constantly through a ¼” by ¼” channel within the cell. The Labview program will work using a thermocouple near the sample and an amplifier to control the output to the program to the resistance heater.