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Unformatted text preview: t frazzled, tattered, cracked, or damaged. Inspect the plugs; make sure
they are not bent or damaged. Make sure that only 3-wire grounded, doubleinsulated, or isolated wiring is used for 110–115 V AC applications.
Bench-top centrifuges should be anchored securely so that if vibration occurs, they
will not “walk” off the edge of the bench or knock over bottles and equipment. These
rules apply to the safe operation of centrifuges:
● If vibration occurs, stop the centrifuge immediately and check the counterbalance
load. If present, check the swing-out buckets for clearance and support.
● Always close the centrifuge lid before operating the centrifuge; keep it closed while
the centrifuge is running.
● Do not leave the centrifuge until full operating speed is attained and the machine
appears to be running safely without vibration.
● If the centrifuge has no brake, allow the centrifuge to coast to a stop. If it has a
brake, use the brake, not your hand, to stop the centrifuge.
● If requested by your laboratory instructor, clean centrifuge rotors and buckets regularly; use a noncorrosive cleaning solution.
Some laboratories are equipped with steam outlets at the laboratory benches; in other
laboratories, students set up their own steam-generating equipment as needed. Steam
is very hot and can severely burn the skin and underlying tissues. Wear thick cloth or
leather gloves, safety goggles, a face shield, and a laboratory apron or coat when you
work with steam. Never direct steam toward any person.
When carrying out a steam distillation, minimize the accumulation of condensate
28 students short index 1/15/03 12:45 PM Page 29 in the distillation flask. Remember that the heat of condensation of steam is very
high. Overfilling of the flask is less likely if condensation from the entering steam line
is trapped and if the flask is heated or insulated to prevent excessive condensation.
Do not flood the condenser by running the steam in too fast. Using High-Pressure Air
Many laboratories are equipped with outlets for pressurized air. Air under...
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This document was uploaded on 02/27/2014 for the course PHYS 1B at UCSD.
- Spring '07