Reciprocating pump

A reciprocating pump comprising:

• a pump chamber which is able to flow a liquid;
• a suction port which enables a liquid to be suctioned into the pump chamber;
• a discharge port which enable a liquid in the pump chamber to be discharged;
• a reciprocating device which is capable of reciprocating in the pump chamber by a drive device and enables a liquid to be suctioned into the pump chamber from the suction port and enables the liquid to be discharged from the discharge port due to the reciprocating;
• valve devices which are disposed between the pump chamber and a flow route on the suction port side and a flow route on the discharge port side, are openable and closable in response to a change in a liquid pressure in the pump chamber, which is produced depending on the reciprocating of the reciprocating device, allow a liquid to flow in an opened state, and block a liquid from flowing in a closed state;
• a detection device that is able to detect a period of time during which the valve device is in the opened state or in the closed state in a predetermined cycle;
• and
• an arithmetic device that performs an arithmetic operation to obtain pump volumetric efficiency or a flow rate based on a comparison between a period of detection time detected by the detection device and a period of time during which the valve device is in the opened state or in the closed state in the predetermined cycle during normal operation.