An apparatus comprising: a sensor body including a low-pressure side and a high-pressure side; a sensor configured to measure differential pressure; and first and second pressure inputs, the first pressure input associated with the low-pressure side of the sensor body and the second pressure input associated with the high-pressure side of the sensor body, the pressure inputs configured to apply at least one input pressure from the low-pressure side and the high-pressure side to the sensor, each pressure input comprising: a barrier diaphragm (208, 210) configured to move in response to pressure; and an overload diaphragm (216, 218) configured to limit movement of the barrier diaphragm, wherein the overload diaphragm is configured to exert a preload force against the sensor body; wherein the overload diaphragm of each pressure input is conifgured to move away from the sensor body in response to a pressure that overcomes the preload force, characterised in that the overload diaphragm of each pressure input includes multiple convolutions; wherein bases of the convolutions are conifgured to provide the preload force against the sensor body, and tops of the convolutions are separated from the sensor body by gaps; or wherein tops of the convolutions that are non-adjacent are configured to provide the preload force against the body; and tops of the convolutions between the non-adjacent convolutions are separated from the sensor body by gaps. a sensor body including a low-pressure side and a high-pressure side; a sensor configured to measure differential pressure; and first and second pressure inputs, the first pressure input associated with the low-pressure side of the sensor body and the second pressure input associated with the high-pressure side of the sensor body, the pressure inputs configured to apply at least one input pressure from the low-pressure side and the high-pressure side to the sensor, each pressure input comprising: a barrier diaphragm (208, 210) configured to move in response to pressure; and an overload diaphragm (216, 218) configured to limit movement of the barrier diaphragm, wherein the overload diaphragm is configured to exert a preload force against the sensor body; wherein the overload diaphragm of each pressure input is conifgured to move away from the sensor body in response to a pressure that overcomes the preload force, characterised in that the overload diaphragm of each pressure input includes multiple convolutions; wherein bases of the convolutions are conifgured to provide the preload force against the sensor body, and tops of the convolutions are separated from the sensor body by gaps; or wherein tops of the convolutions that are non-adjacent are configured to provide the preload force against the body; and tops of the convolutions between the non-adjacent convolutions are separated from the sensor body by gaps. a barrier diaphragm (208, 210) configured to move in response to pressure; and an overload diaphragm (216, 218) configured to limit movement of the barrier diaphragm, wherein the overload diaphragm is configured to exert a preload force against the sensor body; wherein the overload diaphragm of each pressure input is conifgured to move away from the sensor body in response to a pressure that overcomes the preload force, characterised in that the overload diaphragm of each pressure input includes multiple convolutions; wherein bases of the convolutions are conifgured to provide the preload force against the sensor body, and tops of the convolutions are separated from the sensor body by gaps; or wherein tops of the convolutions that are non-adjacent are configured to provide the preload force against the body; and tops of the convolutions between the non-adjacent convolutions are separated from the sensor body by gaps.