SLAU880C December 2022 – May 2024 ULC1001
The second burst in a typical calibration sequence is for temperature calibration, CONTROL_Burst_Cal_Region_Temp (5). The temperature is calibrated at a single frequency that is far from any resonance frequency in the LCS's impedance response. An example is shown in Figure 4-2. The temperature slope constant, USER_Params_tempParams_slope_CperOhm_Q27, and the calibration temperature, USER_Params_tempParams_calTemp_C_Q21, must be set to properly calibrate the LCS temperature. The temperature slope is determined by measuring the LCS impedance across temperature and finding the slope of the best fit line where the x-axis is impedance and the y-axis is temperature, the inverse of the example figure. The calibration temperature, calTemp, is the ambient temperature (in Celsius) of the LCS when calibration is run. The impedance decreases as the temperature increases making the temperature slope constant negative. When the calibration sequence is run, the temperature slope constant, USER_Params_tempParams_constant_C_Q21, is set to an appropriate value.