Measurement system and liquid delivery control method

An electrophoresis measurement system comprises an electrophoresis device 1 and a computer (2, Fig. 16). The electrophoresis device includes a phoresis medium container 20 for storing a phoresis medium, a capillary (11, Fig. 5) configured to store the phoresis medium, and a delivery mechanism 60 for delivering the phoresis medium in the container to the capillary. The computer measures a filling time taken to fill the capillary with the phoresis medium, and changes a delivery pressure by detecting a change in the delivery pressure based on the filling time and a relationship between the filling time and the delivery pressure (Fig. 19). The delivery pressure may be changed by changing a drive current to a plunger (61, Fig. 3) of the delivery mechanism. Delivery may be operated a predetermined number of times at the changed delivery pressure. A delivery amount may be corrected, and an estimated delivery amount determined according to a dispersion in the delivery amount based on the changed delivery pressure.