The torque sensor has a body. A first gastight chamber is defined at least partly by the body. A pressure sensor is connected with the gastight chamber for measuring the pressure in the gastight chamber. A pressure to torque converter is connected to the pressure sensor. The gastight chamber is arranged to change its volume by deformation of the body when the body is subjected to a torque wherein the volume change causes a change of pressure of the enclosed gas in the gastight chamber.