| 摘要 |
PURPOSE:To detect the contact of a nozzle with the surface of a liquid to be inspected, when the nozzle is lowered to the surface of the liquid. CONSTITUTION:A vessel 6 wherein a liquid 4 to be inspected is held is disposed between a pair of electrodes 8 and 10 disposed opposite to each other and an electroconductive nozzle 12 is inserted into this vessel 6. An oscillator 14 is connected to the electrode 8, while a receiver 16 is connected to the electrode 10, and the nozzle 12 is connected to a zero potential level being common for these oscillator 14 and receiver 16. When the fore end 12a of the nozzle lowers and comes into contact with a liquid surface 4a, an electrostatic capacity between the paired electrodes 8 and 10 changes, and with this change, a signal transmitted from the oscillator 14 to the receiver 16 also changes. On the basis of this change of the signal, a determinator 18 makes determination as to whether or not the fore end 12a of the nozzle comes into contact with the surface 4a of the liquid to be inspected. |
