The invention has the objective of offering a sensor the allows for measuring the pressure force of the springs on the carbon brushes as well as the actual brush pressure on its contact surface. This is obtained by measuring between the carbon brush, and there is limited space through its holder, and the contact surface and is therefore characterized by the fact that the sensor is thinner than 4 mm, and that it is provided with a target (4) which is suspended in the sensor (1) by means of a mechanically deformable section (3), and where the sensor is fitted with one or more strain gauges (2) that is/are set up as such that it can detect the shearing of the mechanical deformable measuring section under pressure. In contrast to the existing measuring sensors, the measuring strips also connect the suspension points of the mechanically deformable elements with the sensor and/or the suspended target or measuring point through which sensitivity increases and makes the sensor useful for such applications.