Tandem Technique for Fluid Testing
DAYTON UNIV OH RESEARCH INST
Pagination or Media Count:
A spectrometers analytical sample stand is modified to incorporate a conductivity sensor to measure the electrical properties of liquids prior to spectrometric oil analysis SOA. The sensor is positioned either in the bottom of the fluid sample container or in a probe dipped in the oil container. The sensor configuration is designed for high sensitivity by using coplanar electrodes of a highly conductive material such as copper with large surface area sheathed in a protective alloy material and mounted on a nonconductive substrate. The sensor electrodes are on the order of several hundred micrometers in width and positioned very closely so that the distances between them are on the order of their width. Any small changes in the conductance of the oil sample can easily be detected. The electrodes are connected to a circuit where the signal is integrated and printed a few seconds prior to initiation of SOA. Conductance measurements provide values proportional to the magnitude of oil degradation. A fresh oil of the same formulation as that of the used oil being measured may be used to establish a precise zero baseline and any deviation from this value is indicative of thermal and oxidative stressing of the oil.
- Lubricants and Hydraulic Fluids