Table of Contents

Chapter 1: Laboratory Work

1.2 Behavior and Precautions

The experiments you'll be doing in these laboratories don't involve much particularly dangerous equipment or material. Still, one ought to develop the habits of good lab practice. Most of these are just good common sense: don't play Ultimate with the digital voltmeters, think before you stick your hand into anything, and like that.

A. General Behavior:

  1. Use your time in the lab for the purposes it's been provided for. Any kind of horseplay is completely out of place.
  2. Don't start working with equipment until your instructor says to. He will often have particular instructions you need to hear first.
  3. Don't exchange equipment between setups of the same experiment; there may be differences between apparently identical items that you're not aware of. In general, leave other setups alone - if your equipment has any bugs, bug your instructor.
  4. Maintain good housekeeping in your work area at all times.
  5. When you're done working, leave your experimental area in at least as good order as you found it in.
  6. Look for and obey any warning signs, caution labels, and such. When you meet unfamiliar equipment, read carefully whatever instructions are provided before you start to use it.
  7. NEVER, under ANY circumstances, work alone in the laboratory.

B. Electrical Equipment:

  1. Handle wires and cables by their terminals when connecting or disconnecting them; never yank wires loose.
  2. Any exposed voltages over 30 volts should be considered potentially dangerous. Ordinary 110V and 220V power lines can be very dangerous.
  3. Always disconnect the power source before working on any electric circuit. Remember that capacitors can remain charged up for a while after power to the circuit has been turned off.
  4. Use only one hand when touching any part of a "live" circuit - keep the other hand behind you.
  5. NEVER EVER EVER override or bypass any safety features that are part of the equipment, cobble three-prong plugs into two-hole outlets, etc. Whoever built the safety feature into the instrument probably had a reason!

C. Other:

  1. Never allow the direct (or specularly reflected) beam from a laser to fall on the eye. Even the very low-power lasers you will encounter in elementary physics labs can damage the retina. These lasers can't damage you in any other way, however.
  2. Treat with respect any unfamiliar or exotic light source. A strong mercury-vapor lamp, carbon arc, etc. emit ultraviolet light which can damage the eye.
  3. Ionizing radiation sources should always be treated with great respect. The radioactive sources you'll encounter in elementary labs are sealed sources of a few microcuries or less. These are not dangerous in any way, but even so should not be left in contact with your person for any extended period. Stronger sources, and ANY unsealed source, are to be considered dangerous. The X-ray equipment is potentially very dangerous and is ONLY to be used under direct supervision of the instructor.

Be aware of any particularly delicate pieces of equipment and use extra care around them; damage wastes everyone's time and money. Any malfunctioning or damaged equipment, or any accident, should be reported to your lab instructor immediately.

Section 1-3