Liquid chromatograph with flow controller

Claim 1

In a liquid chromatograph which includes a solvent tank, a pump, a sample injection element, a column, a detector, and conduits for successively connecting said solvent tank, said sample injection element, said column and said detector together, said detector including a sample solution inlet and a reference solution inlet and said column being connected between said pump and said sample solution inlet of said detector, the improvement wherein said liquid chromatograph includes a flow controller connected in parallel with said column between said pump and said reference solution inlet of said detector, said flow controller comprising a fluid inlet, a fluid outlet, an internal chamber, a diaphragm in said internal chamber dividing said internal chamber into an upper chamber and a lower chamber, an inlet passage connecting said upper chamber with said fluid inlet, an adjustment valve positioned in said inlet passage and connected to said diaphragm, an adjustment passage connecting said upper chamber with both said lower chamber and said fluid outlet, a needle valve capable of closing off said adjustment passage, a micrometer head to adjust said needle valve, and a compression spring positioned inside said lower chamber to bias said diaphragm toward the upper chamber.