Advantages of Mercury Switch | disadvantages of Mercury Switch
This page covers advantages and disadvantages of Mercury Switch and its basics. It mentions benefits or advantages of Mercury Switch and drawbacks or disadvantages of Mercury Switch.
What is Mercury Switch?
The switch which uses blob of mercury in a glass bulb for its switching operation is known as mercury switch. It can be used as tilt switch. Mercury remains in its liquid state from -38 to +356 degreeC.
The figure-1 depicts mercury switch with mercury blob inside. In this figure, the contacts are open as mercury is on the opposite side of the metal contacts. This is the open state of the switch.
When bulb is tilted, mercury blob rolls to the end where metal contacts are present. This makes mercury switch pass current through it and lights the bulb as shown in the figure-2.
Benefits or advantages of Mercury Switch
Following are the benefits or advantages of Mercury Switch:
➨Mercury functions as excellent electrical conductor
➨It offers very high surface tension.
➨Empty space of bulb is filled with inert gas. This prevents oxidation of electrodes. Hence mercury switch offers very long operating life.
➨It is visible as its color is silvery shining.
➨It is highly durable as mercury does not evaporate easily.
Drawbacks or disadvantages of Mercury Switch
Following are the drawbacks or disadvantages of Mercury Switch:
➨Mercury is an environmental hazard. Due to this, its use is restricted by many countries across the world.
➨It can not be used outside the range -380C to +356 0C.
➨Mercury is poisonous and hence it is harmful if tube is broken. Need to keep away from children.
➨It is very expensive.
➨As many countries have prohibited its use, the mercury switches are not available easily.