| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrostatic capacity type liquid sensor prevented from erroneous operation by widening a detection range of a semiconductive substance. SOLUTION: An insulating film 31 is formed to the inner peripheral surface becoming a contact surface coming into contact with a coating solution is formed to a ring-shaped detection electrode 30 by PFA coating. The inner peripheral surface is exposed to the inside of a pipe part 22 through which the coating solution 12 passes. Therefore, the resistance value between the detection electrode 30 and the pipe part 22 being an earth electrode increases to become almost infinite and the detection circuit in a circuit part 25 detects the coating solution 12 only by a change in electrostatic capacity between the detection electrode 30 and the pipe part 22 being the earth electrode in spite of the resistance value. Further, since the detection circuit becomes almost infinite in resistance value, even if the change in electrostatic capacity is small, the semiconductive substance can be detected. Accordingly, a range capable of detecting the semiconductive substance is widened and the arroneous operation of an electrostatic capacity type liquid sensor is prevented. COPYRIGHT: (C)2006,JPO&NCIPI |
