Abstract: Vehicle wheel tire inflation pressure, e.g. an aircraft undercarriage wheel tire, is measured in real time by a sensor assembly mounted on a rotary part of the wheel. The assembly includes a piezoresistive cell exposed to inflation gas pressure and an electronics module comprising an assembly of three printed circuit boards (PCB). A power signal transmitted from the vehicle to the electronics module via a rotary transformer is conditioned by PCB to provide an energising signal for the cell. Pressure and temperature signals output by the cell are received by the PCB and converted to digital form before being applied to address locations in a look-up table of PCB which holds pre-calibrated cell outputs. Data from the look-up table is processed to obtain a corrected real time pressure value which is transmitted to the vehicle. If desired, a temperature value may also be transmitted.