EM Test
esd NX30
Instruction Manual
V 1.00.7
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3
INTRODUCTION
Under appropriate ambient conditions, both material objects and even the human body itself can become charged with elec-
trical energy. This effect is due to "electrostatics", a phenomenon that has been known since the earliest times. Thales von
Milet (600 BC) noticed how amber attracted very light particles when it was rubbed. Touching a charged item against a con-
ductive object leads to a charge equalization through a spark discharge, which produces a brief but powerful electromagnet-
ic field.
3.1
Electrostatic discharge (ESD)
This effect can be explained as follows: Two insulating substances with differing dielectric constants become charged when
rubbed together, i.e. one material gives electrons to the other one. This effect is known as electrostatic charging.
The same can happen to a person. When somebody walks around in a dry atmosphere on carpet while wearing shoes with
good insulating properties, a charge of several thousand volts can be built up. If, now, that person comes close to a conduc-
tive surface, the charge that he or she is carrying flows away through a hefty spark discharge.
The high equalizing current that flows, and the associated large electromagnetic field that hence results, can cause electron-
ic devices (computers, terminals, process controllers, vehicle electronics, solid state devices, credit or memory cards, etc.) to
malfunction or even be destroyed.
3.2
Simulation
A systematic investigation of electronic equipment and installations to determine their electromagnetic compatibility (EMC)
is, today, a necessity if one is not prepared to suffer the economic disadvantages that could otherwise ensue. As a logical
consequence, appropriate testing is now a legal requirement for the sale of electronic products within the EU.
The ESD test plays an important role in the range of interference sensitivity tests. It simulates frequently occurring effects
and guides the development engineer to any weak spots in an instrument or item of equipment through a combination of
high voltage and high frequency properties.
A simulation device must be constructed such that it reproduces practical conditions realistically. Furthermore, the results
obtained (interference sensitivity threshold) must be reproducible.
The interference immunity of an instrument is not only depending on its construction, it is also largely dependent on the
quality or the consistency of the mass production techniques used. Knowing this has led to the demand for individual testing
or at least random sample testing.
Further weak spots, which could affect the overall interference immunity, can arise through the assembly of instruments into
complete systems because of the installation method used, the cabling and the earthing. An ESD check on systems is there-
fore also prescribed. Such tests provide valuable information about the immunity of the system to effects that occur only
sporadically under operating conditions and hence represent difficult to detect sources of disruption.
The ESD simulator esd NX30 fulfils the requirements of numerous applications in an ideal manner, thus:
Ergonomic shape:
For non-tiring use.
Operation:
Operating elements and display always in view of the user. Constant check on the
test values.
Battery-powered:
(esd NX30 only)
Independence from a mains power feed.
Carrying case:
(esd NX30 only)
Generator and its accessories can be readily packed and conveniently transported.
Microprocessor-control:
All the functions are "on-board", including a pre-settable counter, pre-programmed
test values, discharge voltage detection, etc.
Precision:
The test parameters are maintained precisely for reliably reproducible tests.
Flexibility:
The specifications prescribed in the standards are more than fulfilled in every re-
spect. The instrument also offers many additional handy features.
Safety:
The high voltage generator is automatically deactivated if the instrument remains
unused for a period of time.
Longterm operation:
Automatic longterm operation for stationary applications with the generator mounted
on a tripod.
Application field:
Development optimization, type-approval, EMC certification, batch testing (individu-
ally), testing of fully installed systems.
