PHYSICAL QUANTITY DETECTION DEVICE

Provided is a physical quantity detection device capable of not only measuring tire air pressure without using a sensor component other than a strain sensor, but also detecting a load and wear from a strain signal corrected using information on the tire air pressure. The physical quantity detection device according to the present invention detects air pressure of a tire at a reference level of a signal waveform of the strain sensor, and detects a load and wear of the tire from a strain signal corrected by the air pressure of the tire. The physical quantity detection device according to the present invention holds a reference value stored in a storage unit as a table, and detects each physical quantity by comparison with the reference value.