In the automatic amount note device liquid level method of detection and the automatic amount note device

摘要

PURPOSE: To improve the injection speed by detecting inner pressure increase in a tubing system with a pressure sensor, reversely rotating a pump and returning the inner pressure in the tubing system to the atmosphere pressure at the time when a nozzle is lowered from above a sample vessel. ;CONSTITUTION: When a nozzle 14 is lowered as a very small amount of air is discharged from the edge of the nozzle 14, inner pressure in a tubing system increases from a pump 18 to the nozzle 14 through an air tube 24 at the time point when the edge of the nozzle reaches a liquid surface of a sample 10. When a pressure sensor 26 detects the pressure in the tubing system and detection pressure exceeds a threshold value, it is detected that it reaches the liquid surface. Just after liquid surface detection, lowering of the nozzle 14 is stopped, and the edge of the nozzle is advanced from the liquid surface to specified depth. A control part receives an output signal of the sensor 26, the pump 18 is sucked on the basis of inner pressure change in the tubing system, and the inner pressure in the tubing system is enforcedly returned to the atmospheric pressure. Thereby nozzle positioning for a suction start position and making a reference state for sucking the sample of tubing system inner pressure can be performed speedily.;COPYRIGHT: (C)1997,JPO