Mercury Displacement Relays
Mercury displacement relays use mercury as a contact material instead of metal contacts. Because the mercury is liquid, mercury displacement relays can cycle faster and will last for more cycles than electro-mechanical relays. Additionally, mercury displacement relays will not burn out as quickly since there is no physical contact-to-contact wear.
Mercury displacement relays typically have to be mounted in a vertical orientation in order to work properly. Additionally, they can explode if overheated from cycling too fast or if they are overpowered.
