How to Use float sensor: Examples, Pinouts, and Specs

A float sensor, manufactured by R.M ENTERPRISE with part ID SENSOR, is a device designed to detect the level of liquid within a tank or container. It operates using a buoyant float that moves with the liquid level, triggering a switch or sending a signal when a specific level is reached. This simple yet effective mechanism makes float sensors highly reliable for liquid level monitoring.

• Water level monitoring in tanks and reservoirs
• Industrial liquid level control systems
• Automotive fuel tank level detection
• Home appliances such as washing machines and dishwashers
• Agricultural irrigation systems

The following table outlines the key technical details of the R.M ENTERPRISE float sensor:

The float sensor typically has two wires for connection. The table below describes the wiring:

1. Wiring the Sensor:

   • Connect the red wire to the positive terminal of the power supply (5V to 24V DC).
   • Connect the black wire to the input pin of a microcontroller or to ground, depending on the circuit design.
   • If using with a microcontroller, ensure a pull-up resistor is used if required.

2. Circuit Design:

   • The float sensor acts as a switch. When the float rises or falls to the set level, the internal contact changes state (NO to NC or vice versa).
   • Use the sensor output to trigger an action, such as turning on a pump or sending a signal to a monitoring system.

3. Example Circuit:

   • Connect the sensor to an Arduino UNO as follows:
     • Red wire to 5V pin on the Arduino.
     • Black wire to a digital input pin (e.g., D2) on the Arduino.

Below is an example code to read the float sensor's state using an Arduino UNO:

// Float Sensor Example Code
// This code reads the state of the float sensor and prints it to the Serial Monitor.

const int floatSensorPin = 2; // Connect the black wire to digital pin 2
int sensorState = 0;         // Variable to store the sensor state

void setup() {
  pinMode(floatSensorPin, INPUT); // Set the float sensor pin as input
  Serial.begin(9600);            // Initialize serial communication
}

void loop() {
  sensorState = digitalRead(floatSensorPin); // Read the sensor state

  if (sensorState == HIGH) {
    // If the sensor is HIGH, the float is at the trigger level
    Serial.println("Liquid level reached!");
  } else {
    // If the sensor is LOW, the float is below the trigger level
    Serial.println("Liquid level below threshold.");
  }

  delay(500); // Wait for 500ms before reading again
}

• Ensure the sensor is mounted securely in the correct orientation (vertical or horizontal) as per the application.
• Avoid exposing the sensor to temperatures or chemicals beyond its specified limits.
• Use proper waterproofing techniques for wiring connections in wet environments.
• Test the sensor's functionality before integrating it into critical systems.

1. Sensor Not Responding:

   • Cause: Loose or incorrect wiring.
   • Solution: Double-check all connections and ensure proper polarity.

2. False Triggering:

   • Cause: Electrical noise or unstable power supply.
   • Solution: Use a capacitor across the power supply terminals to filter noise.

3. Sensor Stuck in One State:

   • Cause: Float mechanism obstructed by debris or dirt.
   • Solution: Clean the sensor and ensure the float moves freely.

4. No Output Signal:

   • Cause: Damaged sensor or incorrect voltage.
   • Solution: Verify the operating voltage and replace the sensor if necessary.

Q1: Can the float sensor be used with liquids other than water?
A1: Yes, the float sensor can be used with various non-corrosive liquids. However, ensure the liquid is compatible with the sensor's material (polypropylene).

Q2: How do I switch between Normally Open (NO) and Normally Closed (NC) modes?
A2: Some float sensors allow switching between NO and NC by inverting the mounting orientation. Refer to the manufacturer's instructions for details.

Q3: Can the sensor be used in high-pressure environments?
A3: The float sensor is not designed for high-pressure applications. Use a sensor rated for high pressure if required.

Q4: Is the sensor suitable for outdoor use?
A4: The sensor can be used outdoors if proper waterproofing and protection from extreme conditions are ensured.