Method and apparatus for degassing a liquid and analytical device having the apparatus

A method for degassing a liquid by means of a piston pump unit having a receiving chamber serving for accommodating the liquid to be degassed and connected with at least one supply line and at least one drain line, and a piston seated in the receiving chamber for performing stroke movements and liquid sealing the receiving chamber on one end, the method comprises the steps of:

• drawing liquid via the supply line into the receiving chamber by performing a first stroke movement of the piston in the case of a blocked drain line and open supply line;
• producing a negative pressure in the receiving chamber by continuing the first stroke movement of the piston in the case of blocked supply line and blocked drain line;
• and
• opening the drain line and removing a gas phase present in the receiving chamber from the receiving chamber via the drain line by performing a second stroke movement of the piston directed counter to the first stroke movement, in the case of an opened drain line and a blocked supply line.

An apparatus for performing a method for degassing a liquid by means of a piston pump unit having a receiving chamber serving for accommodating the liquid to be degassed and connected with at least one supply line and at least one drain line, and a piston seated in the receiving chamber for performing stroke movements and liquid sealing the receiving chamber on one end, the method comprises the steps of:

• drawing liquid via the supply line into the receiving chamber by performing a first stroke movement of the piston in the case of a blocked drain line and open supply line;
• producing a negative pressure in the receiving chamber by continuing the first stroke movement of the piston in the case of blocked supply line and blocked drain line;
• and opening the drain line and removing a gas phase present in the receiving chamber from the receiving chamber via the drain line by performing a second stroke movement of the piston directed counter to the first stroke movement, in the case of an opened drain line and a blocked supply line;
• the apparatus, comprising:
• a piston pump unit having a receiving chamber serving for accommodating the liquid to be degassed;
• a piston movable in said receiving chamber and liquid sealing said receiving chamber on one end
• at least one supply line connected with said receiving chamber;
• at least one drain line connected with said receiving chamber;
• a valve unit, especially one or more valves with associated control mechanisms or a multiport valve, by means of which said supply line and said at least one drain line are selectively blockable, at least at times;
• and
• a control unit, which is embodied to control the apparatus for performing the method.

An analytical device for determining a measured variable of a liquid sample, comprising an apparatus for performing a method for degassing a liquid by means of a piston pump unit having a receiving chamber serving for accommodating the liquid to be degassed and connected with at least one supply line and at least one drain line, and a piston seated in the receiving chamber for performing stroke movements and liquid sealing the receiving chamber on one end, the method comprises the steps of:

• drawing liquid via the supply line into the receiving chamber by performing a first stroke movement of the piston in the case of a blocked drain line and open supply line;
• producing a negative pressure in the receiving chamber by continuing the first stroke movement of the piston in the case of blocked supply line and blocked drain line;
• and opening the drain line and removing a gas phase present in the receiving chamber from the receiving chamber via the drain line by performing a second stroke movement of the piston directed counter to the first stroke movement, in the case of an opened drain line and a blocked supply line;
• the apparatus, comprising:
• a piston pump unit having a receiving chamber serving for accommodating the liquid to be degassed;
• a piston movable in said receiving chamber and liquid sealing said receiving chamber on one end
• at least one supply line connected with said receiving chamber;
• at least one drain line connected with said receiving chamber;
• a valve unit, especially one or more valves with associated control mechanisms or a multiport valve, by means of which said supply line and said at least one drain line are selectively blockable, at least at times;
• and
• a control unit, which is embodied to control the apparatus for performing the method, and further comprising:
• a processing system for treating the liquid sample, wherein the treating comprises adding at least one reagent to the liquid sample;
• a measuring transducer for registering a measured value of the treated liquid sample correlated with the measured variable or a reaction product formed by treating the liquid sample;
• said control unit, which is embodied to control the processing system;
• and
• an evaluating unit, which is embodied for determining the measured variable based on the measured value registered by said measuring transducer.