Sirona DAC UNIVERSAL - Page 16

60 53 362 D3472
16 D3472.201.10.20.02 07.2016
2Safety instructions Sirona Dental A/S
2.1Electrostatic discharge Operating Instructions DAC UNIVERSAL
An electrostatic discharge is:
● perceptible at 3,000 V or higher
● audible at 5,000 V or higher (cracking, crackling)
● visible at 10,000 V or higher (arc-over)
The transient currents resulting from these discharges have a magnitude
of over 10 amps. They are not hazardous for humans because they last
for only several nanoseconds.
Tip: 1 nanosecond = 1/1,000,000,000 second = 1 billionth of a second
Voltage differentials exceeding 30,000 volts per centimeter may lead to a
charge transfer (electrostatic discharge, lightning, arc-over).
Integrated circuits (logical circuits and microprocessors) are used in order
to implement a wide variety of functions in a device. The circuits must be
miniaturized to a very high degree in order to include as many functions
as possible on these chips. This leads to structure thicknesses as low as
a few ten thousandths of a millimeter. Integrated circuits that are
connected to wires leading externally are therefore particularly at risk
from electrostatic discharge.
Even voltages that are imperceptible to the user can cause breakdown of
the structures, thus leading to a discharge current that melts the chip in
the affected areas. Damage to individual integrated circuits may cause
malfunction or failure of the unit.