5" eTape Liquid Level Sensor + extras [discontinued]

The eTape Liquid Level Sensor is a solid-state sensor with a resistive output that varies with the level of the fluid. It does away with clunky mechanical floats, and easily interfaces with electronic control systems. The eTape sensor's envelope is compressed by the hydrostatic pressure of the fluid in which it is immersed. This results in a change in resistance that corresponds to the distance from the top of the sensor to the surface of the fluid. The sensor's resistive output is inversely proportional to the height of the liquid: the lower the liquid level, the higher the output resistance; the higher the liquid level, the lower the output resistance.

This is a very unique sensor. We haven't seen anything else that is affordable and accurate for measuring liquid level. This sensor seems like it would be a handy addition to a hydroponics, aquarium, fountain, or pool controller, or perhaps measuring a rain tube. This particular sensor is the 5" version, and it includes a 4-pin connector and 560Ω 5% resistor. The connector is so you don't have to solder directly to the delicate pins. Instead, just solder to the connector and plug it onto the sensor.

Since the sensor is resistive, it is easy to read it using a microcontroller ADC pin. Check the tutorials tab for a quick-start pointer!

Please Note: This product only comes with the 5" bare Tape Liquid Level Sensor. In our demo, we set up a 12" enclosed version with an Adafruit Metro, a TB6612 Stepper Motor Driver Breakout Board, and an Automotive Gauge Stepper Motor to demonstrate functionality.

Technical Details

// the value of the 'other' resistor #define SERIESRESISTOR 560       // What pin to connect the sensor to #define SENSORPIN A0    void setup(void) {   Serial.begin(9600); }   void loop(void) {   float reading;     reading = analogRead(SENSORPIN);     Serial.print("Analog reading ");    Serial.println(reading);     // convert the value to resistance   reading = (1023 / reading)  - 1;   reading = SERIESRESISTOR / reading;   Serial.print("Sensor resistance ");    Serial.println(reading);     delay(1000); }