MIA-LID 高位报警开关

GENERAL

 

MIA-LIDEC-L20-70D is a dryness sensor using acoustic waves. Since the detection method of this sensor is same as a MIA-LIDEC alarm sensor which does not have a moving part, it excels in durabil- ity and reliability.

It is optimum for empty detection and initial watch of level detection.

 

PRINCIPLE OF OPEARTION

 

In MIA-LIDEC, the LIDEC sensor which generates acoustic waves by a piezo-electric element is put on the upper part, and acoustic waves are sent to a metal rod.

The head of a metal rod has a structure which makes it easy to spread acoustic waves.

When there is no liquid in the surroundings of the part at this head, the acoustic waves spread in the metal rod is reflected at the metal rod head and returns to the upper part.

If a liquid level goes up and a liquid gets to exist at the head of a metal rod, acoustic waves are spread in a liquid and absorbed, and the acoustic waves do not return to the upper part.

The circuit which distinguishes the existence of this reflective acous- tic wave is established in an electric-circuit part, and the existence of the liquid in a metal rod tip position is detected. In an electric-circuit part, the existence of this reflective acoustic waves are changed into the size (6mA / 18mA) of a current signal, and alarm status is trans- mitted to the remote place by the signal loop of two-wire system.