Technical Articles

What is ESD?

by Andy on June 8, 2007

ESD-Safe Symbol Before you can understand ESD (electrostatic discharge), you first need to understand what static electricity is. Static electricity is the buildup of an electrical charge through an imbalance of electrons. This is most obvious when your hair stands up or when your clothes stick together right after pulling them out of the dryer. This happens because one item has a positive charge and the other item has a negative charge.

Technically speaking, an ESD event is defined as an event where there is a transfer of a charge between two bodies with different electrical potentials. The most notable ESD event is the occurrence of lightning (300,000,000 volts). However, the most common one you will physically experience is the shock you receive when you touch a metal doorknob after walking across a carpet on a cold dry day. Lightning is obviously an ESD event on a grand scale with huge transfers of electrons compared to the small discharge present when touching the doorknob.

If we don’t get injured when we are shocked by touching the doorknob, then why do we have precautions against ESD? ESD does do damage when it happens. Just like a lightning bolt can potentially kill a person, a small ESD event can potentially destroy an electric component. Small electronic components such as Service Mount Devices (SMDs) are very susceptible to ESD events. Whereas a person can only begin to feel an ESD event between 2,000 and 3,000 volts, a small component can be damaged or even be destroyed by just a few volts of discharge. By wearing grounding equipment and following ESD precautionary procedures, we reduce the risk of damaging these components.

For our selection of ESD products visit the All-Spec website or the Electrostatic Discharge Association website for more information.

Looking for more information about the basics of ESD?


How does a diopter work?

by Andy on June 6, 2007

Diopter dilemma? Read on for more information on selecting the proper magnifier for you.

A diopter is a unit of measurement describing the optical power of a lens or curved mirror. When shopping for magnifiers, consider this: The diopter is equal to the reciprocal of the focal length measured in meters. For example a 5 diopter lens brings light rays to focus at 1/5 meter. Each diopter increases the size of the viewed object by 25% when the object is at its full focal length from the lens. Remember that as the lenses become stronger and magnification increases, viewing areas and focal length decrease.

An “x” usually follows the magnification number. This “x” is used to express power or the size of the object in relationship to its actual size.

How to select the magnifier for you:

  • Decide how much magnification you need. In doing so, remember that if you increase the magnification, the focal length and the viewing area will be smaller.
  • Determine which diopter you need.
  • Make sure you check the focal length and the diameter of the lens in accordance with your task

Magnifier All-Spec Industries provides all kinds of magnifiers to fit your needs.