Mercury Switch Analysis GROUP MEMBERS: Darrell Biggs Melissa Bauer Frank Bain Fred DeSanti

Project Focus Research the dangers of mercury switches Analyze their usefulness Discuss alternatives to mercury tip/ tilt switches Compare costs of the different alternatives

Mechanics of a Tilt/Tip Switch Consists of a glass or metal encasement Two electrode contacts on one side Free floating ball of mercury or another conductor enclosed in the encasement This ball allows current to flow between the electrodes

Switching Device in “Off” Position Electrodes Tube Ball Bearing or Mercury Ball Figure 1.1

Switching Device in “On” Position Tube Electrodes Ball Bearing or Mercury Ball Figure 1.2

Design of Mercury Switch Figure 1.3a

Design of Ball Switch Figure 1.3b

Actual Mercury Switch and Ball Switch Mercury switch Ball switch Figure 1.4

Why Mercury is Used Liquid at room temperature Sensitive to small movements Surrounds the electrode which allows it to pass larger amounts of current Conducts electricity

Products Which Contain Mercury Switches Thermostats that contain 2 to 6 switches each Space heaters where it is used as a safety device Steam irons (safety device) Flotation devices to control the amount of fluid in a tank Mobile homes used as a leveling device Car trunk and hood lamps

Hazards of Mercury Use HIGHLY TOXIC Can remain in the atmosphere for up to a year Does not degrade in the environment Primary source of exposure is through water supply Causes severe damage to body through inhalation and ingestion of contaminated fish

What Alternatives Are There to Mercury Switches? Switches which use ball bearings instead of mercury Experimental material with mercury-like properties in a vacuum but unstable in air (high cost)

Life Cycle Cost Comparison $20,000$35,000$1,400 $50,000$35,000Minimal Research & Development Disposal Machining & Operating Mercury Switch Ball Switch Table 1.1

Multi-Attribute Economic Analysis Customer Point of View FactorsWeightMSBS Table 2.1

Multi-Attribute Economic Analysis Company Point of View FactorsWeightMSBS Table 2.2

Solutions Discontinue use of mercury in household products Pass legislation to control the use and recycling of mercury in industry Arrange collection facilities for used mercury

Acknowledgements Mr. Robert Romano, President Comus Intl., Nutley, NJ Dr. James Luxhoj, Rutgers University Dr. Priscilla Hayes, Cook College

Mercury Switch Analysis ?? QUESTIONS ??