The cloths pin and aspirin water sensor is quite old – I remember seeing it in an electronics magazine in the 50s or 60s as a rain detector for parked convertables.

Conductivity Sensors for Pure Water Applications UniCond conductivity / resistivity sensors are available in 2-electrode and 4-electrode models to cover all ranges of measurement.

Environmental Monitoring with Arduino ... conductivity of water. These first couple chapters also give the reader a familiarity with a couple different ways to indicate the value the sensors ...

The sensor measures electrical conductivity, which is an indicator of ion concentration, using a nine-electrode array, and processing, developed by Murata to reject variations in contact quality. Also ...

An example of success in this type of application is where a high speed CombiLyz Conductivity Sensor supplied by sensing and instrumentation specialists BAUMER has made an important contribution at ...