Electronic float with infrared refraction or Optical Level Sensor.

The optical liquid level sensor is useful in all solutions where electrical contact with liquid (water) is not recommended.

Small in size, the optical level sensor detects the presence of liquid if in direct contact with water, due to the simple principle of operation, it allows very high sensitivity (~1 mm).

The cable, contains the 4 terminals: two of the infrared led and two of the infrared sensor.

Principle of operation: the presence of liquid refracts the light beam and the generated negative signal inhibits the sensor. If the liquid is in air, the refraction generates an active signal on the sensor, which outputs the signal to the output cable.

The optical liquid sensor should be connected to a system such as Arduino or PICMicro that handles the signals and activates the pump control operation. One could also use olo a relay, with exercise voltage not exceeding 15 mA.

At this link you will find the explanation of the sensor operating principle, example code, in English. (I have not personally verified the code)

In the package you will find the optical level sensor,the locking nut and the two resistors for connection to 5V.

Specifications.

• difraction liquid level sensor
• operating voltage: 5 Vdc
• max output current: 15 mA
• Operating temperature: - 25 ~ 105 ℃
• low output level: < 0.1 V
  
• high output level: > 4.6 V
• Sensor accuracy: ±1.0 mm
• Material: polycarbonate-PC
• Service life: 50,000 hours
• Dimensions: 28 x 28mm/ 1.1 x 1.1 inches
• Cable length: 500mm
• Weight: 26g

Pinout

•    Red      : GND
  
•   Yellow  : GND
•     Blue    : VCC 5Vdc
•    White : Out (dc output <0.1 Vdc - >4.6 Vdc)