MODELLING THE DYNAMIC MECHANISM OF A METAL BULB TEMPERATURE TRANSMITTER

Seigha I. Fetepigi, Zekieni R. Yelebe* and Revelation J. Samuel

Department of Chemical/Petroleum Engineering,

Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.

E-mail: yelebezr@gmail.com

ABSTRACT: A mathematical model for the dynamic mechanism of a metal bulb temperature transmitter is developed. The model was formulated based on the mechanism of heat transfer, transmission of pressure along the capillary tube and the bellows movement. The combination of these three mechanisms produced the desired result of developing a transfer function that relates changes in bellows movement to changes in the temperature of the liquid in which the gas filled metal bulb is immersed. To obtain this transfer function requires that the inflow rate into the bellows be expressed as the ratio of difference in pressure to resistance at the entrance to the bellows. The transfer function obtained was translated to real time expression using the inverse Laplace transform technique.