| 摘要 |
PURPOSE:To receive almost none of the influence of liquid, to eliminate troubles in electrolysis, and to maintain high detection accuracy by detecting whether the liquid level reaches a target reservoir liquid level or not by using an electromagnetic or sound wave. CONSTITUTION:When the liquid level in a liquid storage tank 10 is lower than the target reservoir liquid level, the electromagnetic wave or sound wave omegatransmitted by a transmitter 16 is received by a receiver 18 directly without passing through the liquid and a detecting means 20 detects its intensity being larger than a set level value to detect the liquid level hot reaching the target reservoir liquid level. Further, when the liquid level rises above the target reservoir liquid level, the electromagnetic wave or sound wave omega transmitted by the transmitter 16 travels in the liquid and is received by the receiver 18, or reflected or refracted by the liquid surface and received by the receiver 18; and its intensity decreases below the set value and the detecting means detects that to detect the liquid level reaching the target reservoir liquid level. |
