Introduction: PP Float Switch Tutorial


Polypropylene Float Switch is a type of level sensor. It is used to detect the level of liquid within a tank. Most of the common usage of the flow switch can be summarised as below:

  • pump control
  • tank water level indicator
  • alarm
  • pair up with other device for control.


  • Max Contact Rating : 10W
  • Max Switching Voltage : 220V DC/AC
  • Max Switching Current : 1.5A
  • Max Breakdown Voltage : 300V DC/AC
  • Max Carry Current : 3A
  • Max Contact Resistance : 100m ohm
  • Temperature Rating : -10 / +85 Celsuis
  • Float Ball Material : P.P
  • Float Body Material : P.P
  • Thread Dia(Approx) : 9.5mm / 0.374"
  • Switch Body Size : 23.3 x 57.7mm / 0.9" x 2.27"(Max D*H)
  • Cable Length : 36cm / 14.2"
  • Color : White
  • Net Weight : 70g

Step 1: Material Preparation

In this tutorial, we used LED as output to show how this PP Float Switch works. The items needed in this tutorial is listed as below:

  1. Arduino Uno
  2. USB Cable Type A to B
  3. Male to male jumper wire
  4. LED
  5. Resistor (220 ohm)

Step 2: Hardware Installation

Diagram above shows the simple connection between PP Float Switch and Arduino Uno:

  1. Terminal 1 > GND
  2. Terminal 2 > D2

and LED is connected to Arduino Uno:

  1. LED > D8

Once the connection is completed, the circuit is ready to run by supplying power with USB cable.

Step 3: Insert Source Code

Source code is provided here which is used in this tutorial for running the whole circuit.
  1. Download the attached source code and open it with Arduino software or IDE.
  2. Upload the source code into your Arduino.

Step 4:

When PP Float Switch is pulled up, the LED will be lighted up. The circuit is opened when one does not pull up the switch and circuit is closed when switch is being pulled up. PP Float Switch utilizes a magnetic reed switch, consisting of two contact sealed in polypropylene. A magnet inside will attract the two contact together if switch is pulled up and vice versa.

Step 5: Video

The video shows the tutorial on PP Float Switch in the water. Once the water has reached the level where the switch is at, the switch will be pulled up by the buoyancy of water and thus activate the circuit.