A sensor system comprises a first sensor, a second sensor, a high pass filter, and a summation unit. The first sensor senses an environmental parameter and outputs a first electronic signal with a response having a first time constant. The second sensor senses the environmental parameter and outputs a second electronic signal with a response having a second time constant greater than the first time constant. The high pass filter has a filter time constant roughly equal to the second time constant and filters the first electronic signal, outputting a filtered first electronic signal in which changes in a level or value of the first electronic signal with transition times that are less than the filter time constant are passed. The summation unit receives the filtered first electronic signal and the second electronic signal and outputs a sum of the filtered first electronic signal and the second electronic signal.