A removable pressure sensor which is configured to be removably mounted in an intermediate part of an elastically deformable tube for transferring a liquid, the removable pressure sensor comprising: a main body portion ; and a pressure measurement element that is disposed in the main body portion , wherein the main body portion comprises a base portion having a tube mounting recessed portion into which the intermediate part of the tube is removably fitted so as to cause the tube to be elastically deformed and to cause a circuit pressure of the liquid inside the tube to be measured by the pressure measurement element , and a lid portion configured to hold the tube inside the tube mounting recessed portion in a state in which the tube mounting recessed portion of the base portion is closed, wherein a width of a cross section of the tube mounting recessed portion is configured to be smaller than an external dimension of the tube, characterized in that the removable pressure sensor further comprises: a temperature sensor that measures a temperature of an environment in which the tube is positioned; and a control unit that acquires temperature information of the environment from the temperature sensor, acquires the circuit pressure of the liquid inside the tube from the pressure measurement element , and corrects the circuit pressure of the liquid inside the tube measured by the pressure measurement element , in accordance with a value of the temperature. a main body portion ; and a pressure measurement element that is disposed in the main body portion , wherein the main body portion comprises a base portion having a tube mounting recessed portion into which the intermediate part of the tube is removably fitted so as to cause the tube to be elastically deformed and to cause a circuit pressure of the liquid inside the tube to be measured by the pressure measurement element , and a lid portion configured to hold the tube inside the tube mounting recessed portion in a state in which the tube mounting recessed portion of the base portion is closed, wherein a width of a cross section of the tube mounting recessed portion is configured to be smaller than an external dimension of the tube, characterized in that the removable pressure sensor further comprises: a temperature sensor that measures a temperature of an environment in which the tube is positioned; and a control unit that acquires temperature information of the environment from the temperature sensor, acquires the circuit pressure of the liquid inside the tube from the pressure measurement element , and corrects the circuit pressure of the liquid inside the tube measured by the pressure measurement element , in accordance with a value of the temperature. a temperature sensor that measures a temperature of an environment in which the tube is positioned; and a control unit that acquires temperature information of the environment from the temperature sensor, acquires the circuit pressure of the liquid inside the tube from the pressure measurement element , and corrects the circuit pressure of the liquid inside the tube measured by the pressure measurement element , in accordance with a value of the temperature. <EOS>