A sensor apparatus (230, 310a, 310b),comprising: a mount adapted to be attached to a support; and a sensor element (120, 130, 140, 395a, 395b) adapted to be detachably connected to the mount; wherein the mount comprises a first connecting element and a second connecting element, wherein each of the first and second connecting elements (10, 15) comprises a compressible and/or expandable body, the sensor element (120, 130, 140, 395a, 395b) comprises a substantially circular or cylindrical recess (125, 145), the recess (125, 145) is adapted to sealingly engage with the second connecting element by a push fit, or pressure fit connection, wherein the sensor element (120, 130, 140, 395a, 395b) comprises a sensor probe for a capacitive touch sensor; characterized in that the mount comprises an end portion at, or near a location distal or opposite from a portion of the mount adapted for receiving or connection with the sensor element (120, 130, 140, 395a, 395b), wherein the end portion is adapted to receive a further connecting element, wherein the mount comprises the further connecting element adapted to connect to the end portion, wherein the further connecting element comprises a conductive material, and the mount is adapted such that the further connecting element, connects a mount plate to the end portion, wherein the mount may comprise at least one intermediate portion between the end portion and the mount plate being translucent or transparent, such that the at least one intermediate portion is adapted to diffuse and/or propagate light towards to the sensor element (120, 130, 140, 395a, 395b), wherein the mount is adapted such that rotation of the further connecting element in a first direction, moves the end portion towards the mount plate and wherein the first connecting element is adapted such that the movement of the end portion towards the mount plate causes compression of the first connecting element between the mount plate and the end portion or the at least one intermediate portion, wherein the first connecting element is adapted such that compression of the first connecting element in an axial direction causes expansion of the first connecting element in a radial direction, wherein the end portion comprises an electrical contact, and the further connecting element provides electrical connectivity between the mount plate and the electrical contact, wherein the end portion comprises a sensor circuit (360a, 360b, 440), wherein the electrical contact is electrically connected to, or forms part of, the sensor circuit (360a, 360b, 440), and the sensor circuit (360a, 360b, 440) is adapted for capacitive touch sensing and for detecting and/or measuring relative changes and/or durations of electro-static charges present at the sensor probe. a mount adapted to be attached to a support; and a sensor element (120, 130, 140, 395a, 395b) adapted to be detachably connected to the mount; wherein the mount comprises a first connecting element and a second connecting element, wherein each of the first and second connecting elements (10, 15) comprises a compressible and/or expandable body, the sensor element (120, 130, 140, 395a, 395b) comprises a substantially circular or cylindrical recess (125, 145), the recess (125, 145) is adapted to sealingly engage with the second connecting element by a push fit, or pressure fit connection, wherein the sensor element (120, 130, 140, 395a, 395b) comprises a sensor probe for a capacitive touch sensor; characterized in that the mount comprises an end portion at, or near a location distal or opposite from a portion of the mount adapted for receiving or connection with the sensor element (120, 130, 140, 395a, 395b), wherein the end portion is adapted to receive a further connecting element, wherein the mount comprises the further connecting element adapted to connect to the end portion, wherein the further connecting element comprises a conductive material, and the mount is adapted such that the further connecting element, connects a mount plate to the end portion, wherein the mount may comprise at least one intermediate portion between the end portion and the mount plate being translucent or transparent, such that the at least one intermediate portion is adapted to diffuse and/or propagate light towards to the sensor element (120, 130, 140, 395a, 395b), wherein the mount is adapted such that rotation of the further connecting element in a first direction, moves the end portion towards the mount plate and wherein the first connecting element is adapted such that the movement of the end portion towards the mount plate causes compression of the first connecting element between the mount plate and the end portion or the at least one intermediate portion, wherein the first connecting element is adapted such that compression of the first connecting element in an axial direction causes expansion of the first connecting element in a radial direction, wherein the end portion comprises an electrical contact, and the further connecting element provides electrical connectivity between the mount plate and the electrical contact, wherein the end portion comprises a sensor circuit (360a, 360b, 440), wherein the electrical contact is electrically connected to, or forms part of, the sensor circuit (360a, 360b, 440), and the sensor circuit (360a, 360b, 440) is adapted for capacitive touch sensing and for detecting and/or measuring relative changes and/or durations of electro-static charges present at the sensor probe.