Modeling Of Temperature Probes In Convective Media
Adson Ferreira da Rocha, Jonathan W. Valvano · 2005
This paper discusses the dynamic behavior of probes embedded in convective media during temperature measurements. In certain conditions the temperature measured by a probe can be written as the convolution of the true temperature with the impulse response of the probe. We present a general method to find the natural response of any kind of probe, and then we present results for a more realistic 1-D model for the thermistor probe in a thermodilution catheter. The results of these analyzes can be applied to enhance the dynamic response of temperature measurements made by probes in convective media. We begin with a methodology for developing a convolutional model for temperature probes in a medium with a time-independent convection coefficient, even though it can be non-uniform along the boundary. The requirement of a constant, non-uniform convection coefficient will make it possible to write a linear time-invariant relationship between the true and measured temperatures. The bulk temperature of the fluid will be the magnitude to be measured. The step response measured by the finite size probe can be written: