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 Tube Electrodes Ball Bearing or Mercury Ball Figure 1.1 Switching Device in “On” Position Tube Ball Bearing or Mercury Ball Electrodes Figure 1.2 Design of Mercury Switch Figure 1.3a Design of Ball Switch Figure 1.3b Actual Mercury Switch and Ball Switch Ball switch Mercury 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 Research & Development Machining & Operating Disposal Mercury Switch $20,000 $35,000 $1,400 Ball Switch $50,000 $35,000 Minimal Table 1.1 Multi-Attribute Economic Analysis Factors Weight MS BS Life cycle cost .35 60 50 Environmental .10 Effects Safety .25 30 100 40 90 Ease of Use .30 80 80 Sum = 1.0 58.0 74.0 Customer Point of View Table 2.1 Multi-Attribute Economic Analysis Factors Weight MS BS Life cycle cost .30 60 50 Environmental .15 Effects Safety .35 50 100 30 90 Ease of Use .20 70 70 Sum = 1.0 50.0 75.5 Company Point of View 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 ??