Abstract: A contrast sensor for evaluating identification markings and a method of evaluating identification markings on detecting objects using a contrast sensor, having at least one light transmitter and at least one light receiver, with the light receiver having a single photodiode; having a control and evaluation unit for evaluating the light receiver signal of the light receiver, and having an output for a sensor signal that is formed by the control and evaluation unit on the basis of the light receiver signal, wherein the identification marking has lettering or a marking; an elongate illumination field is projected by the light transmitter onto a region of the identification marking narrow in the direction of movement; and the control and evaluation unit compares a reception signal sequence having a plurality of contrast transitions with a stored reception signal sequence and outputs the sensor signal in dependence on the comparison.

Abstract: A contrast sensor for evaluating identification markings and a method of evaluating identification markings on detecting objects using a contrast sensor, having at least one light transmitter and at least one light receiver, with the light receiver having a single photodiode; having a control and evaluation unit for evaluating the light receiver signal of the light receiver, and having an output for a sensor signal that is formed by the control and evaluation unit on the basis of the light receiver signal, wherein the identification marking has lettering or a marking; an elongate illumination field is projected by the light transmitter onto a region of the identification marking narrow in the direction of movement; and the control and evaluation unit compares a reception signal sequence having a plurality of contrast transitions with a stored reception signal sequence and outputs the sensor signal in dependence on the comparison.

Abstract: A method of evaluating print marks of detection objects using a print mark sensor and a print mark sensor for evaluating print marks having at least one light transmitter and at least one light receiver having a control and evaluation unit for evaluating the light receiver signal of the light receiver and having an output for a sensor signal that is formed by the control and evaluation unit on the basis of the light receiver signal.

Abstract: A method for controlling movement of a piston in a metering device is described. The method comprises supplying a fluid by actuating the metering device's piston, wherein compression or expansion of the fluid causes corresponding temperature variations. The method further comprises superposing a corrective movement onto the piston movement, with the corrective movement at least partly compensating for at least one of thermal expansion and contraction of the fluid induced by the temperature variations. In one embodiment, the corrective movement imposed onto the piston movement comprises two components: a reduction (74) of the compression jump (73), and a subsequent increase (75) of the piston's forward displacement rate (71) during a period (76) of time (72).

Abstract: A liquid delivery system having at least one channel, at least one valve within that channel, at least one flow sensing device within that channel, and a pressure source downstream of the valve capable for generating variable pressures.

Abstract: A supply flow path for supplying a solvent is described. The supply flow path includes metering devices each with a piston, the metering devices being adapted for metering the solvent through separate source paths feeding the supply flow path. The supply flow path further includes a control unit adapted for controlling the metering devices' piston movement in accordance with solvent pressure, wherein a variation of the solvent pressure gives rise to a corresponding variation of a solvent volume contained in the supply flow path or a part thereof. The control unit is adapted for compensating for the variation of the solvent volume by corresponding movements or forward or backward displacements of the pistons.

Abstract: A method for controlling movement of a piston in a metering device is described. The method comprises supplying a fluid by actuating the metering device's piston, wherein compression or expansion of the fluid causes corresponding temperature variations. The method further comprises superposing a corrective movement onto the piston movement, with the corrective movement at least partly compensating for at least one of thermal expansion and contraction of the fluid induced by the temperature variations. In one embodiment, the corrective movement imposed onto the piston movement comprises two components: a reduction (74) of the compression jump (73), and a subsequent increase (75) of the piston's forward displacement rate (71) during a period (76) of time (72).

Abstract: There is provided a method that includes, (a) monitoring a pressure on a fluid being conveyed through an intake tube into a chamber by a pump, (b) determining a deviation of the pressure from a predefined value, (c) determining a blockage of the intake tube based on the deviation, and (d) determining an amount of an adjustment of a parameter of the pump to compensate for the blockage.

Abstract: A variety of methods for operating a chromatography system are presented. Specifically, methods for operating a pumping system within a chromatography system are presented. The methods presented are directed to pumping apparatus in which very small amounts of fluid are pumped through the system. A number of techniques for detecting and compensating for leaks are presented as well as a number of techniques for operating the pumping system.

Abstract: A supply flow path for supplying a solvent is described. The supply flow path comprises a metering device with a piston, the metering device being adapted for metering the solvent. The supply flow path further comprises a control unit adapted for controlling the metering device's piston movement in accordance with solvent pressure, wherein a variation of the solvent pressure gives rise to a corresponding variation of a solvent volume contained in the supply flow path or a part thereof. The control unit is adapted for compensating for the variation of the solvent volume by a corresponding corrective movement of the piston.

Abstract: A liquid delivery system having at least one channel, at least one valve within that channel, at least one flow sensing device within that channel, and a pressure source downstream of the valve capable for generating variable pressures.