The MC5740 characterises the piezo sensors’ behaviour over time with a range of diagnostic tools, including instantaneous measurements of temperature, leakage, capacitance, and noise, and an oscilloscope mode to display piezo output waveforms.
The alongside example shows a definite relationship between temperature and sensitivity. However, the continuous clear delineation between real sensor hits and base-level noise is indicating a reliable installation. The report also displays the dynamic range of a piezo sensor. The predominant vehicles (cars) are causing sensor peaks below one volt while heavy vehicles regularly result in peaks over the 2.5V full-scale reading.