| 摘要 |
PURPOSE:To make it possible to detect the liquid surface of a specimen accurately and simply by jetting gas through sample pipet, and detecting the time when the tip of the pipet comes into contact with the liquid surface of the specimen based on the change in pressure. CONSTITUTION:A first pipet-descent controlling means 6 discharges the gas from the inside of a sample pipet 3 and lowers the pipet 3 from an upper stop-point position. When the rise of the gas pressure in the pipe 3 is detected with a pressure-change detecting means 5, it is judged that the tip of the pipet 3 reaches the liquid surface of a specimen (k) in a specimen cup 1. The discharge of the gas is stopped with a gas feeding stopping means 7. Then, a second pipet-descent controlling means 8 lowers the pipet 3 by the minute specified amount and slightly dips the tip nozzle into the specimen (k). After the specimen (k) is sucked, the pipet 3 is returned to the upper stop-point position. Thus, the liquid surface of the specimen can be detected accurately and simply under the state wherein there is no dispersion of detecting sensitivity without making the apparatus itself complicated and large. |
