Advantages of The Mercury Switch
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Advantages of The Mercury Switch Advantages of the mercury switch over other types are that the contacts are enclosed, so oxidation of the contact points is unlikely. In hazardous locations, interrupting the circuit will not emit a spark that can ignite flammable gasses. Contacts stay clean, and even if an internal arc is produced, the contact surfaces are renewed on every operation, so the contacts don't wear out. Even a small drop of mercury has a low resistance, so switches can carry useful amounts of current in a small size. The sensitivity of the drop to gravity provides a unique sensing function, and lends itself to simple, low-force mechanisms for manual or automatic operation. The switches are quiet as there are no contacts that abruptly snap together. The mass of the moving mercury drop can provide an "over center" effect to avoid chattering as the switch is tilted. Multiple contacts can be included in the envelope for two or more circuits. |