Table   3-2.—Rubber   Gloves pair  of  electrical  safety  rubber  gloves  rated  for  the appropriate voltage (see table 3-2). 5. Have a co-worker stand by; don’t work alone. Make sure your co-worker knows where to secure the power in case of emergency. Follow these four safety precautions  whenever you take measurements on energized equipment: 1.  Always  use  test  probes  with  safety  guards  or barriers on the probe tips. This will prevent your hand from  in  advertently  touching  the  probe  tip. 2. Always used insulated alligator clips. 3. Always keep your body clear of any metal parts of the equipment on which you’re working. 4. Try and keep one hand in your pocket or behind your  back  when  taking  the  measurement.  This  will prevent  you  from  creating  a  ground  path  for  electric current flow through your body from hand to hand. Here is an excerpt from a mishap report that will show   the   importance   of   following   the   above precautions: Member could not get alligator clip on test lead to stay on probe so he held clip to probe with right  hand.  Member  violated  safety  precautions by  continuing  to  hold  clip  and  probe  while energizing the test lead with 1200 volts. Soon thereafter,  the  member  touched  the  ground  lead and received serious shock. The member was treated for minor burns on the palm. MEASURING VOLTAGE ABOVE 300  VOLTS All  the  safety  procedures  for  measuring  voltages below 300 volts apply when you are measuring voltages above  300   volts.   But,   the   big   difference   when measuring voltages above 300 volts is that you must NOT  hold  the  test  probe  in  your  hand  while  the equipment is energized. Instead, you’ll attach the test probes while the equipment is de-energized. Here are the safety procedures you should follow: 1 . 2 . 3  . 4  . 5 . 6  . 7 . 8 . 9  . Follow  all  the  preliminary  safety  procedures  for measuring  voltage  below  300   volts   before beginning your measurements. Make sure the equipment you are working on is DE-ENERGIZED. Follow the required tag-out procedures. With   a   shorting   probe,   discharge   all   high- voltage capacitors. Attach   the   ground   probe   of   the   measuring device first. Secure the other probe of the measuring device to the test point to be measured. Make sure the measuring device is setup for the voltage level and polarity to be measured. Energize  the  equipment  under  test,  make  the measurement,   and   then   de-energize   the equipment. Discharge all high-voltage capacitors. Remove the probes from the equipment. ELECTROSTATIC  DISCHARGE PRECAUTIONS Electrostatic   discharge   (ESD)   can   destroy   or damage   many   electronic   components   including integrated  circuits  (ICs)  and  discrete  semiconductor devices. Certain devices are more susceptible to ESD damage than others. Because of this, warning symbols are now used to identify ESD-sensitive (ESDS) items (fig.  3–1). Certified 2M technicians are trained in procedures for reducing the causes of ESD damage. The procedures are similar for all levels of maintenance. Some of the protective measures you should follow to prevent ESD damage  are:    Ground the work benches where ESDS devices will be handled. 3 -4