PURPOSE: To eliminate detection error of specimen liquid surface even if a plurality of specimens are sucked and a tip of a dispensor is in contact with a test tube by transmitting and receiving ultrasonic wave to a nozzle, and controlling the driving mechanism of the nozzle based on a recieption signal.
CONSTITUTION: A disc 3 is driven by a driver 4 and turned, then a test tube 2 containing a specimen 1 is moved to a dispensing position. A dispensor 21 is turned by a dispensor driving mechanism 25 and moved up and down so that a new tip 11 is set onto a holder 12. Next, the dispensor is 21 turned turned to a dispensing position and a dispensor shaft 24 descends toward the specimen 1. Simultaneously, ultrasonic wave pulse is transmitted from a ultrasonic wave transmitting/receiving unit 23 and detection of reflection wave is started. After the lapse of time from the start time of transmission to the completion time of reciplocation to the foremost end of the tip 11 reception is made by the unit 23, and processed by a ultrasonic circuit 26 so that change occuring when the foremost end of the tip 11 reaches the liquid face of specimen 1 is detected. After the detection of change a computer 31 controls the mechanism 25 to stop descending of the shaft 24. Thereafter, the specimen 1 is sucked from the tip 11 into a tube 13 by a syringe pump 15. The specimen 41 in a bottle 43 is then sucked in the same manner.
NIIYAMA YASUSHI
UCHIDA HIROYASU
Next Patent: JPS6341999