| 摘要 |
PURPOSE:To control effectively a pulsative current of a column sending liquid moving phase in a liquid chromatograph, by increasing the speed of a pump driving motor at the time of overlapping discharge stages of plural plunger type pump units. CONSTITUTION:When a discharge stage of each plunger type pump unit is moved from a stationary state period to an overlapping period, a slit of a disk rotating synchronously with a driving motor is detected optically and the overlapping period is detected by an overlapping period detector 44. Further, a changeover switch 38 is switched and a pump driving motor 30 is controlled through a voltage-frequency transducer 46 basing on an difference output obtained by a comparison amplifier 36 between a set point of a standard level setting circuit 32 and the pressure of a sending liquid moving phase to a column by a pressure detector 40 and then, the speed of the motor 30 is increased. Hereby, the overlapping period of the discharge stage generating a pulsative current is shortened and the pulsative current of the column sending liquid moving phase is controlled effectively. |
