Turbidity (Water Transducer) Sensor

The working principle of the turbidity sensor sensor: When light passes through a certain amount of water, the amount of light penetration depends on the amount of dirt in the water. As the amount of dirt increases, the light that penetrates the water sample decreases, and the turbidity sensor measures the amount of light transmitted to calculate the turbidity of the wash water.

The turbidity sensor provides these turbidity measurements to a washing machine or dishwasher controller, with the washing machine and dishwasher controller determining the time of each wash cycle. These judgments are based on a comparison between the measured value of the purified water (measured at the beginning of the washing cycle) and the measured value of the washed water measured at the end of the washing.

By measuring the turbidity of the wash water, the washing machine can only wash the time required to wash the laundry which is not very dirty, thereby saving energy, so that the end user saves energy.

Specifications

• Voltage: 3.3 – 5V
• Sensor default out analog value 0~4.5V
• Measuring range: 0-1000 NTU

Connection

• V+→ Arduino 5V
• V- → Arduino GND
• S → Arduino A2

Arduino Sketch

int ledPin = 13;                // Connect an LED on pin 13, or use the onboard one
int sensor_in = 2;                 // Connect turbidity sensor to Digital Pin 2

void setup(){
  pinMode(ledPin, OUTPUT);      // Set ledPin to output mode
  pinMode(sensor_in, INPUT);       //Set the turbidity sensor pin to input mode
}

void loop(){
  if(digitalRead(sensor_in)==LOW){       //read sensor signal
    digitalWrite(ledPin, HIGH);   // if sensor is LOW, then turn on
  }
  else{
    digitalWrite(ledPin, LOW);    // if sensor is HIGH, then turn off the led
  }
}