Dynamic analysis of the NPP pressure sensor system

The aim of the work was to develop on-line methods of control and diagnostic of pressure sensors at a NPP. The analysis was carried out along two lines: i) The detection system including the sensor itself was modeled theoretically to obtain and study its transfer function, and to establish correspondence between the spectral characteristics of the pressure signal. ii) The numerical processing of the signal using the AR technique to reconstruct the transfer function and evaluate the system's response, to a step impulse, as well as the spectral analysis. The hydraulic model presented indicate that the spectral lines observed at ∼ 10 Hz are due to longitudinal oscillations of water in the system branches, while the response time of the detection system is effectively the time of signal retardation in the porous ceramic diaphragms of the δ-cell of the sensor itself. (author)