AUTOMATIC ANALYZER
The occurrence of splash of a sample or a reagent from a nozzle tip is prevented during shifting of a dispensing mechanism. An automatic analyzer includes a nozzle for sucking liquid to be dispensed; a pump for allowing suction of the liquid into the nozzle and generating pressure variations; a pipe line connecting the nozzle with the pump; and a shifting mechanism for shifting the nozzle in horizontal and vertical directions. In the automatic analyzer, the pipe line is at least partially composed of a flexible tube. The flexible tube has an upward or downward convex bending portion in the middle thereof. The convex bending portion changes in position and shifts along with the shifting mechanism at a nozzle side. If the nozzle is shifted horizontally, a value obtained by subtracting a vertical distance between the top of a convex portion of the flexible tube and the uppermost portion of the nozzle from a vertical distance between the tip portion of the nozzle and the uppermost portion of the nozzle is a value ranging from −30 mm to 130 mm.
1 . An automatic analyzer comprising:
a nozzle for sucking liquid to be dispensed;
a pump for generating pressure variations allowing suction of the liquid into the nozzle;
a pipe line connecting the nozzle with the pump; and
a shifting mechanism for shifting the nozzle in horizontal and vertical directions;
wherein the pipe line is at least partially composed of a flexible tube and the flexible tube has an upward or downward convex bending portion in the middle thereof, the convex bending portion changing in position and shifting along with the shifting mechanism at a nozzle side, and
wherein when the nozzle is shifted horizontally, a value obtained by subtracting a vertical distance between a top of a convex portion of the flexible tube and an uppermost portion of the nozzle from a vertical distance between a tip portion of the nozzle and the uppermost portion of the nozzle is a value ranging from −30 mm to 130 mm.
2 . The automatic analyzer according to claim 1 ,
wherein the value obtained by subtracting the vertical distance between the top of the convex portion of the flexible tube and the uppermost portion of the nozzle from the vertical distance between the tip portion of the nozzle and the uppermost portion of the nozzle is a value ranging from 0 mm to 130 mm.
3 . The automatic analyzer according to claim 1 ,
wherein the value obtained by subtracting the vertical distance between the top of the convex portion of the flexible tube and the uppermost portion of the nozzle from the vertical distance between the tip portion of the nozzle and the uppermost portion of the nozzle is a value ranging from 0 mm to 50 mm.
4 . The automatic analyzer according to claim 1 ,
wherein a segmented gas layer allowing gas to separate liquid from liquid is provided in the liquid in the nozzle and a value obtained by subtracting the vertical distance between the top of the convex portion of the flexible tube and the uppermost portion of the nozzle from a distance obtained by adding a length of the segmented air layer to the vertical distance between the tip portion of the nozzle and the uppermost portion of the nozzle is a value ranging from −30 mm to 130 mm.
5 . The automatic analyzer according to claim 1 ,
wherein the pump is suction-operated during lift of the nozzle.
6 . The automatic analyzer according to claim 1 ,
wherein an electromagnetic valve is installed on a pipe line between the nozzle and the pump, and the nozzle is shifted with the electromagnetic valve closed.