Roche cobas b 221 system User Manual

Roche Diagnostics May 2009
Service Manual · Version 9.0 A-9
cobas b 221 system 1 Safety information
ESD protection measures
Why is ESD protection so important today?
Formerly, current controlling semiconductors were mostly used (TTL, normal
transistors, etc.).
Today the principle of current logic is virtually the only technology in use in MOS
and CMOS components.
Currents generated by an electrostatic discharge (as much as several kV!) destroy the
sensitive component inputs or cause hidden damage. This damage is generally not
immediately detectable.
Another effect is that the clearances inside the ICs continuously become smaller. The
internal wires become thinner and thinner, the allowable maximum input voltages
become smaller and the effects of any discharges become more and more critical.
How can ESD protection be guaranteed?
A continuous discharge is required when working on an electronic assembly. Do this
as follows:
o Use ESD wrist bands (special wrist bands connected to a protective ground).
o Repairs and tests on assemblies must only be conducted on tables with ESD mats
connected to grounds or ESD wrist bands.
o Always pick up components at the edge (e.g. like a photo).
o Components must always be transported in ESD packages or appropriate storage
or shipping containers (use original packaging!).
o Shoes with rubber soles or clothing of synthetic fibers must not be worn in
workshops where electronic components are repaired.
o Use a humidifier if necessary to maintain optimum humidity in the work area.
o Do not touch assemblies or components with the hand after testing.
o Always transport and ship assemblies or components for repair in ESD protective
packaging only. This will prevent further damage that may result in
misinterpretation of the original cause of the fault.
Conclusion
Of course, not all circuit boards and electronic assemblies require such careful
handling. An electrical board that only carries simple plug connectors does not
require ESD packaging.
In cases of doubt always use ESD packaging.
The ESD mat consists of materials that have a very low, defined conductivity (1012 ohms).
The following materials prevent charges caused by friction from building up and protect the
component from damage.
o ESD mats
o ESD packages
o Shipping containers

Roche cobas b 221 system Specifications

General

Brand	Roche
Model	cobas b 221 system
Category	Medical Equipment
Language	English