Simplified Computational Approach for Determining In Situ Probe Spacing of a Dual Probe Heat Pulse Sensor

For the dual probe heat pulse (DPHP) method, the probe spacing r is very important for the calculation of volumetric heat capacity and thermal diffusivity. Separate models for probe spacing correcting resulting from linear and nonlinear deflections have been reported earlier. In this paper, the linear model and the nonlinear model are unified into a single algorithm. Compared with the earlier models, the new model simplifies the procedure. To use the new model, it is not necessary to calculate a deflected angle, and also there is no longer a need to initially identify whether probe deflection is inward or outward. The new r correcting approach provides an easy way to use relationship that accounts for linear and nonlinear probe deflections.