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Apparatus for liquid chromatography

  • US 4,772,388 A
  • Filed: 09/07/1982
  • Issued: 09/20/1988
  • Est. Priority Date: 09/09/1981
  • Status: Expired due to Term
First Claim
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1. Apparatus for rapidly bringing a chromatographic means to equilibrium pressure comprising:

  • pumping system means;

    means for setting a pumping speed for pumping fluid from the pumping system means into said chromatographic means at a predetermined rate of flow;

    means for measuring, after start up of the pumping system means and before equilibrium pressure is reached and at a time of a low value of pressure of said fluid, the pressure of said fluid being transferred from the pumping system means to the chromatographic means;

    means for estimating the equilibrium pressure from said measurements of said pressure made at a low value pressure;

    means for increasing the rate of flow of fluid from the pumping system means under the control of at least said measured pressure until said pressure reaches said estimated equilibrium pressure;

    said means for estimating including means for taking the time derivative of said measured pressure at first and second times and means for multiplying a value equal to substantially the pressure of the fluid being transferred between the pumping system and the chromatographic system at the second point in time by a factor which is the ratio of the value of the time derivative at the second point in time subtracted from the time derivative at the first point in time divided into the time derivative at the first point in time; and

    means for reducing said rate of flow from the pumping system means to said predetermined rate of flow after said pressure reaches equilibrium.

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