Abstract: A tire pressure indicator includes a hollow annular pressure cell fixed fastened to the inner side of the rim for synchronous rotation, the hollow annular pressure cell having a diaphragm that displaces subject to the condition of the tire pressure of the tire, a contactless displacement sensor adapted to detect axial displacement of the diaphragm and to produce a corresponding modulated signal, a signal processor adapted to process the modulated signal from the displacement sensor into a tire pressure signal, a pressure display adapted to display the value of the tire pressure signal output from the signal processor, and a link tube connected between the hollow annular pressure cell and the tire to keep the internal air pressure of the hollow annular pressure cell in balance with the internal air pressure of the tire.

Abstract: A tire pressure indicator includes a hollow annular pressure cell fixed fastened to the inner side of the rim for synchronous rotation, the hollow annular pressure cell having a diaphragm that displaces subject to the condition of the tire pressure of the tire, a contactless displacement sensor adapted to detect axial displacement of the diaphragm and to produce a corresponding modulated signal, a signal processor adapted to process the modulated signal from the displacement sensor into a tire pressure signal, a pressure display adapted to display the value of the tire pressure signal output from the signal processor, and a link tube connected between the hollow annular pressure cell and the tire to keep the internal air pressure of the hollow annular pressure cell in balance with the internal air pressure of the tire.