A medical system comprising: a medical fluid pumping machine comprising a pressure sensor flush mounted on a face of the medical fluid pumping machine; a medical fluid line set comprising a fluid line in fluid communication with a fluid passage formed between a diaphragm (136, 137) and a base (138, 139), the medical fluid line set being configured to be connected to the medical fluid pumping machine in a manner such that the diaphragm of the medical fluid line set aligns with the flush mounted pressure sensor of the medical fluid pumping machine; a mechanical loading member configured to a) protrude away from the diaphragm or cause the diaphragm to protrude outwardly prior to the medical fluid line set being connected to the medical fluid pumping machine, and b) apply a positive force to the flush mounted pressure sensor when the medical fluid line set is connected to the medical fluid pumping machine and the fluid passage is at atmospheric pressure; and a control unit that is in communication with flush mounted pressure sensor and is configured to determine a medical fluid pressure based on a pressure detected by the flush mounted pressure sensor, wherein either: a) the control unit comprises a look-up table that provides a corrected fluid pressure for each pressure detected by the flush mounted pressure sensor; or b) the control unit is configured to calculate a corrected medical fluid pressure by inputting a pressure detected by the flush mounted pressure sensor into an equation. a medical fluid pumping machine comprising a pressure sensor flush mounted on a face of the medical fluid pumping machine; a medical fluid line set comprising a fluid line in fluid communication with a fluid passage formed between a diaphragm (136, 137) and a base (138, 139), the medical fluid line set being configured to be connected to the medical fluid pumping machine in a manner such that the diaphragm of the medical fluid line set aligns with the flush mounted pressure sensor of the medical fluid pumping machine; a mechanical loading member configured to a) protrude away from the diaphragm or cause the diaphragm to protrude outwardly prior to the medical fluid line set being connected to the medical fluid pumping machine, and b) apply a positive force to the flush mounted pressure sensor when the medical fluid line set is connected to the medical fluid pumping machine and the fluid passage is at atmospheric pressure; and a) protrude away from the diaphragm or cause the diaphragm to protrude outwardly prior to the medical fluid line set being connected to the medical fluid pumping machine, and b) apply a positive force to the flush mounted pressure sensor when the medical fluid line set is connected to the medical fluid pumping machine and the fluid passage is at atmospheric pressure; and a control unit that is in communication with flush mounted pressure sensor and is configured to determine a medical fluid pressure based on a pressure detected by the flush mounted pressure sensor, wherein either: a) the control unit comprises a look-up table that provides a corrected fluid pressure for each pressure detected by the flush mounted pressure sensor; or b) the control unit is configured to calculate a corrected medical fluid pressure by inputting a pressure detected by the flush mounted pressure sensor into an equation. a) the control unit comprises a look-up table that provides a corrected fluid pressure for each pressure detected by the flush mounted pressure sensor; or b) the control unit is configured to calculate a corrected medical fluid pressure by inputting a pressure detected by the flush mounted pressure sensor into an equation.