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How water sensors work?

Updated: Jun 30, 2023

With clear under-standing you can involve in a much better way in installing, operating and also improvising water sensor system to meet your specific needs. Good thing is, it is very easy to understand how water sensors work.

Water sensors using water conductivity are most popular in India. Most water level alarms and automation use these type of water sensors only. Depending upon type of device there can be 2, 3, 4 or more water sensor probes in water. These type of water sensors work only in un-processed raw water (ground/sea / tap water), as raw water allows minute sensor signal to flow through it.

Water sensor probes connect water to electronic circuit inside water level alarm or automation device. Device generates a signal and sends it to one sensor probe in water tank (through wire connecting sensors with device). Often this sensor is called reference sensor. The signal from this reference sensor flows to other sensors through water when other sensors immerse in water. As device receives signal back from a sensor, it activates the function configured to that sensor.

Two sensor probe devices, are generally single function devices, like water overflow alarm, low water level alarm or overflow auto stop devices. When both water sensor probes immerse in water, water alarm or auto-stop works. It is not really required to know which water sensor is doing what. So its very easy to install a water level alarm or overflow auto stop using two water sensor probes. The sensing signal flow is as in diagram below

Water Sensor Signal Flow
Water Sensor Signal Flow

Three sensors devices offer two functions. Water level alarm may have both overflow level alarm as well as low water level alarm. Automation with both auto-start and auto-stop function also uses three water sensors most of time. In 3 water sensor devices it is important to know which water sensor is reference signal sensor. Reference signal sensor has to be lower most water sensor in tank. The sensor signal flows from reference sensor to upper sensors as they immerse in water. Diagrams below make it more clear

Water Sensor Signal to Water Tank
Water Sensor Signal to Water Tank

Water sensing signal has reached water tank.

Water Sensor Signal From Low Level Sensor
Water Sensor Signal From Low Level Sensor

Water sensing signal is being conducted back by one sensor to device

Water Sensor Signal From Full Level Sensor
Water Sensor Signal From Full Level Sensor

Water sensing signal is being conducted back to device by both upper level sensors.

To make it easy to install and handle water sensors, SensaSwitch provides 3 or more water sensor devices with a pre-connected water sensor set. Buyer just need to hang the provided sensor set in water tank and connect it to main device.

Devices using more than 3 water sensors work exactly as explained above. Only difference being number of water sensors above reference level sensor. For example water level indicator devices have as many water sensors above reference water sensor as number of water levels indicated on device panel.

Above is very basic know-how to help users have a clear picture in mind as to how water sensors work. Using above information users can adjust water sensor level in water tank or adjust gap between water sensors to suit their specific needs.

Last but not the least, please note above was only about sensaswitch water sensors using conductivity of water. There are water sensors for other type of water also which work in different way. Now what other type of sensors are and how they work is another topic and we shall share in another post.

SensaSwitch provides water sensors for all type of waters like de-minalerized waters, storm / sewage water and industrial effluent. Generally SensaSwitch provides all devices with raw water sensors using conductivity and prices include that only. Processed water sensors or storm/sewage/ETP water sensors are provided on buyer mentioning specific need. Hope you check what we have got on our shop.

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