| 摘要 |
PURPOSE:To prevent generation of shortage of a dispensing quantity by controlling the dispensing quantity by the number of liquid drops dropped and discharged from a nozzle. CONSTITUTION:A sample 2 is sucked up into a nozzle pipe 16, a negative water head of a height difference (h) of a nozzle hole 16b and a liquid level in a pressure governing chamber 20 is applied to the hole 16b, and a voltage pulse 32 of a prescribed quantity is applied in the radial direction of a pressure member 19. The member 19 contracts suddenly in accordance with a rise time of the pulse 32, forms a liquid column 34 by the nozzle hole 16b by applying an external pressure to a pipe 16, and subsequently, the liquid column 34 is cut at the nozzle end by a sudden pressure drop of a pressure chamber 16c by a load elimination of the pulse 32, becomes a liquid drop 17 and is injected into a reaction vessel 14. Accordingly, if a volume of the liquid drop 17 is known in advance, a dispensing quantity of a prescribed quantity can be given as the total number of applied pulses, and a dispense which generates no shortage of the dispensing quantity can be obtained with a high accuracy. |
