Patent ID: 11879877
Assignee: SHIMADZU CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  F | IPC F  G

Claim 3:
4. The binary pump according to claim 3, further comprising:
a pre-compression operation part configured to perform a pre-compression operation of the first pump part so that the first pressure becomes closer to the system pressure while the switching valve is in the second state, and to perform a pre-compression operation of the second pump part so that the second pressure becomes closer to the system pressure while the switching valve is in the first state; and
a compression ratio calculation part configured to obtain a compression ratio of liquid to be delivered by the first pump part based on a relationship between a liquid delivery amount by the first pump part and an increase amount of the first pressure during the pre-compression operation of the first pump part, and to obtain a compression ratio of liquid to be delivered by the second pump part based on a relationship between a liquid delivery amount by the second pump part and an increase amount of the second pressure during the pre-compression operation of the second pump part, wherein
the backflow calculation part is configured to calculate the backflow rate to the first pump part and the backflow rate to the second pump part using the compression ratios obtained by the compression ratio calculation part respectively.