Self-Calibrating Apparatus to Find Dynamic Compressibility of Organic Solids
Abstract
A self-calibrating apparatus has been developed to measure the adiabatic dynamic compressibility of organic solids. The test chamber is a small cavity where bulk cyclic compression is accomplished and monitored with piezoelectric transducers (simple disks). The chamber is different from other chambers of similar design in that it can be re-calibrated at each data point without changing static pressure, opening the chamber, or using a calibration sample. Self-calibration is accomplished using a chamber cavity which is divided into a main chamber and two side-chambers. One side-chamber contains the sample suspended in pressure fluid; the other contains only pressure fluid. The main chamber contains transducers and a remotely operated door. The door may close off either side-chamber or be left open, allowing the three measurement conditions required to calibrate the chamber. Much of the measurement process is monitored or controlled by a Hewlett-Packard HP-85 desktop computer through DC control voltages or an HPIB bus. Data were taken in isothermal runs at pressures stepped down from 8000 or 10,000 psi in 2000, 1000, or 500 psi increments. Poly(vinyl acetate) (PVAc), and polytetrafluoroethylene (Teflon) were tested and the results compared to data obtained by other researchers using other means. This comparison showed that the apparatus yields reliable, useful data. (aw)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 29, 1989
- Accession Number
- ADA219780
Entities
People
- David E. Edmonds
Organizations
- University of Texas at Austin