These are handy little boards if you
are interested in monitoring the level of a liquid in
a vessel. They use Darlington Transistors which enable this
circuit to work with very clean (low conductivity) water.
Unlike other water level detectors that rely on a float
switch, this does not require any moveable switch (although
one can be used, if desired). It detects the presence or
absence of liquid at the tip of the probe. The probe can be
simply 2 wires that when they both come into contact with
the liquid at the same time, a relay closes. The 10A
relay(s) on these boards can turn on or off a pump,
solenoid, alarm (up to 10 A) or be connected to a digital
input line on your DAC card for event logging. They require
12VDC for operation. This board is available in 2
One Probe / One Relay. Useful for
detecting the presence of a spill or leak.
Two Probes / Two Relays. Useful for
detecting high and low level conditions.