For more information, call us at: (703) 836-7378


TEMPEST INC. of Herndon, Virginia ( suburb of WASHINGTON DC ) provides the services of well-qualified experts in the field of electromagnetic interference ( EMI Experts ) to serve as consultants or to provide expert witness testimony in the field of electromagnetic interference ( EMI ), which is also known as:
* electromagnetic compativility( EMC )
* radio frequency interference ( RFI )
* electromagnetic environmental effects ( E3 )
and includes the related technology of
* electrostatic discharge control ( ESD ).

We provide:

We are well qualified experts with the:
* Formal education,
* Official certifications, and
* Practical industrial experience
needed to provide effective testimony
in the field of electromagnetic compatibility.

* Spotting significant errors, omissions, and contradictions
. in testing and trouble-shooting procedures.
* Identifying more effective procedures.
* Spotting design flaws.
* Refuting invalid arguments involving technical matters.
* Spotting logical or technical flaws
. in conclusions and recommendations.

We are proud to say that we have successfully provided these services for
* Law firms,
* industrial clients, and for the
. National Aeronautics and Space Administration.

* We perform formal or informal investigations of electromagnetic interference ( EMI )in our well-equipped testing laboratory whose specialized capabilities exceed those of many much larger firms.
* We can take things apart and determine how they really work.
* We can do the same in the related field of electrostatic discharge control.

* We have a long record of building safe, secure, and reliable electronic devices for the United States government. We can provide practical, credible expertise regarding manufacturing issues. Our products have been personally used by the secretary of defense and by the President of the United States. We build things that work.

* In testimony and depositions, we can explain complicated technical concepts clearly, concisely, courteously, and conclusively, both verbally and in writing, in ways that laymen can understand.

* We are well equipped to securely receive, examine, retreive, transmit and dispose of large amounts of sensitive technical documents.

For more information, call us at 703 836 7378.




For a quick introduction to the terminology used in Electromagnetic compatibility, electromagnetic interference ( EMI ), and closely related fields, please see: this private page of our web site.

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Terminology used in Electromagnetic Compatibility (EMC), electromagnetic interference ( EMI ), and closely related fields:

If you are watching antenna TV and someone turns on a hair dryer, you may see some annoying lines running across the screen. This is because the hair dryer unintentionally acts as a radio transmitter, producing signals that confuse the TV set. This is known as " Electromagnetic Interference " (EMI).

If an engineer were to re-design the hair dryer so that it no longer produced electromagnetic interference, the problem would be solved. The hair dryer and the TV set would now be compatible. This is known as "Electromagnetic Compatibility" (EMC.)

EMI and EMC are used interchangeably to refer to the technology of preventing and eliminating electromagnetic interference.

Other names for this technology include "Radio Frequency Interference " (RFI) and "Radio Interference." Amateur radio operators call it " QRM " and " QRN ."

"Emissions" and "Susceptibility."

The radio noise that the hair dryer makes are its "emissions." The extent to which the TV set malfunctions in the presence of these signals is called its "Susceptibility."

Many EMC standards require tests for both the Emissions that a device makes , and its Susceptibility to other emissions. In Europe, "Susceptibility" tests are called "Immunity" tests.

The field of electromagnetic compatibility now encompasses many sub-specialties. Some of these are:

* Electrostatic Discharge Control (ESD), the prevention of damage from the type of static electricity that you produce by walking across a carpet on a dry day.

* Radiation Hazards (RADHAZ), protection against injuries that can be caused by powerful radio transmitters.

*High Energy Radio Frequency (HERF) protection: Protection against electromagnetic interference that is intentionally caused by mischief-makers.

When you fill your car's gasoline tank, you may see a sign warning you to turn off your cell phone. This is because radio signals, like the ones produced by cell phones, have been known to cause sparks that can ignite gasoline fumes and cause a fire. The term "HERF" is also used to mean "Hazards of Electromagnetic Radiation to Fuel."

*Extremely Low Frequency ( ELF) signals, such as those produced by electrical power lines, have been accused of causing electromagnetic interference and even health problems. The study of ELF signals and their effects is also a part of the overall field of electromagnetic compatibility.

* Electromagnetically Shielded Enclosures are used to block unwanted radio signals from getting in or out. This general term is used to refer to enclosures that can be several stories tall, or small enough to fit on a printed circuit board.

* Shielded Enclosures that are approximately the size of a typical room or office are often called " shielded rooms, " or (in Canada) "Walk-in shielded enclosures" or "Faraday Cages " after the British scientist Michael Faraday who invented the first one, or "Screen Rooms" after the copper screening that was originally used to build them.

* Shielding Effectiveness Testing is the technology used to determine if a sheilded enclosure is working properly. It is also used to determine the effectiveness of different types of shielding materials.

For more information about shielding, see "THE SHIELDED ENCLOSURE HANDBOOK" and our unclassified COURSES. entitled:




* TEMPEST security can be considered a sub-specialty of electromagnetic compatibility. The word TEMPEST is not an acronym. It is just a short name, similar to the term "Apollo " in NASA's first manned moon landing Program.

Most information about TEMPEST security engineering is classified. This means that people who work in TEMPEST security engineering, including TEMPEST INC., are prohibited by the U.S. Government from discussing TEMPEST security matters with anyone who does not have:
a) a verified US security clearance, and
b) a need to know the TEMPEST security engineering information. Both must be verified by the US Government.

For this reason, please do not ask us anything about TEMPEST security matters unless we can verify in advance, through official US government channels, that you meet both of the above criteria. At TEMPEST INC. we are required to report all unusual or suspicious inquiries about TEMPEST security matters. We do this diligently and vigorously.

On the other hand, If you are in the Armed Forces of the United States, or if you are a United States government employee or US government contractor, if you meet the above requirements and you need to talk to an experienced TEMPEST engineer, call us. TEMPEST INC. will respond quickly and effectively.

TEMPEST INC. has a 22 year history of providing practical, timely solutions to a wide variety of TEMPEST security engineering problems.

Although these technologies are related, an expert in one area is not necessarily an expert in another. For example, a Certified TEMPEST Professional may or may not have much experience in fixing electromagnetic interference problems. Similarly, a Certified Electromagnetic Compatibility Engineer may not know very much about TEMPEST security engineering. At TEMPEST INC. we have well-equipped facilities and proven expertise in both TEMPEST security and Electromagnetic Compatibility.

To learn more about Electromagnetic Compatibility, see our one-day course Introduction to Electromagnetic Compatibility" on our "Courses" page. This course is unclassified and open to all.

Copyright 2012 by TEMPEST INC. All rights reserved.



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* An expert Witness or Expert Witnesses in electromagnetic interference ( EMI )
* An expert Witness or Expert Witnesses in radio frequency interference ( RFI )
* An expert Witness or Expert Witnesses in electromagnetic environmental effects ( E3 )
* An expert Witness or Expert Witnesses in electrostatic discharge control ( ESD ).