A first oscillation circuit (331) and a second oscillation circuit (332) are respectively connected to a first pressure sensor (321) and a second pressure sensor (322) and oscillate based on the capacity values of the corresponding pressure sensors. The first oscillation circuit (331) and the second oscillation circuit (332) operate in response to instruction from a CPU (100). The one of the first oscillation circuit (331) and the second oscillation circuit (332) that has received an activation signal from the CPU (100) outputs a signal having a frequency that corresponds to the capacity value of the corresponding pressure sensor. An adjustment circuit (335) is connected to the first oscillation circuit (331) and the second oscillation circuit (332) and allows one of the frequency signals to pass therethrough outputting the signal to the CPU (100).
