Installation schematic; The probe blue top (with the inside!) is what you get.  Ultrasonic sensor probe 12/24Vdc. PVC case. Fit on an 50mm pipe (PVC or any pipe, length up to 6,5m, 250inch). Suitable for water level or any non corrosive liquid medium. Not for any explosive liquid, vapour or damp.

The probe cable wire, is terminated with a RS232 plug that can directly be plugged into the PC.
The probe supply power,10 to 35Vdc 25mA, can be connected to the red (positive) and black (negative) wires coming out of the connector. 12Vdc is enough to measure lengths up to 4m (>150inch). For more, 24Vdc is recommanded.


See also:

See also the hall submersible encoder for dirty liquid level measure
our optical level sensor optosens.html  and hall float switch float.html Float switches.