Mercury Switch 5mm

Mercury switches are commonly used in applications where the tilt of an object is of importance. The switch has two terminals on the inside, with mercury in its liquid state. When the switch tilts, the mercury will flow to the lowest point in the switch and close the circuit between the two terminals. If the mercury switch tilts upside down, the mercury will flow away from the contacts and the switch will be open. 

It is best not to use these switches in cold weather conditions, as the mercury may become solid at a temperature of -38degrees Celsius. Even before the temperature reaches this point, the mercury will become thick, and it may struggle to flow. This may cause false readings on the mercury switch.