The most known and simple level switch consists of a float which is mounted on a moveable arm and magnetically coupled to a micro switch (outside the process). Also versions exist with a spherical float, which contains a small magnet and move upwards a tube. In the tube one or more reed relays are placed. The reed relays will switch as the (magnetic) float passes by. The image below shows a simple float type mechanism.

Advantages of Float level switch

1.    Relatively simple.

2.    It is suitable for various products

3.    Low cost.

Disadvantages of Float level switch

1.    Requires a certain mounting

2.    No reproduction switch point

3.    There is a malfunction in case of build-up.

4.    It is not fail-safe.