© Agilent Technologies 1989–2002 Agilent 3070 / 79000 Site Preparation 5-2
Chapter 5: Site Preparation – Environmental Requirements: Air Quality Requirements
Air Quality
Requirements
This section contains:
â– Introduction, 5-2
â– Corrosive Contaminants, 5-2
â– Particulate Contaminants, 5-2
â– Viscid Contaminants, 5-2
Introduction
As a rule, good air quality is as important for the
reliability of your 3070 / 79000 family system as it is for
your production process. Three types of airborne
contaminants are discussed below. The presence of any
of these contaminants at the site will contribute to
system degradation, resulting in lower reliability and
higher operating costs.
Corrosive Contaminants
Corrosion is a complex form of material deterioration or
destruction by chemical or electrochemical reaction.
The presence of corrosive contaminants (gases) in the
atmosphere is very common in industrial environments.
If ignored, corrosion can eventually degrade system
performance by its effects on high impedance circuits
and low impedance interfaces. It can also deteriorate
most plastics including software storage media. The
effects of corrosive contaminants are usually accelerated
at high humidities or high temperatures.
Corrosives generally cannot be filtered out of the air by
normal filtration methods, and the techniques that must
be used for their removal are complex and costly. If the
source of corrosive contaminants cannot be eliminated,
the system should be installed in an enclosed
environment with a fresh air supply at positive pressure.
Particulate Contaminants
Particulate contaminants (hard particles) consist of
smoke, dust, hair, lint, fibers and miscellaneous organic
and inorganic materials. The presence of these
contaminants in the air can cause system degradation,
especially where disk drives, test fixtures, and low
impedance interfaces are concerned. Particulate
contaminants can be filtered from the air, and
appropriate filters should be included with any air
conditioning installation. Also consider installing "No
Smoking" signs in the area. Tobacco smoke is a
well-known factor in fixture contact contamination. It
causes false failures leading to unnecessary DUT repairs
and higher production costs.
Viscid Contaminants
Viscid contaminants are oily or sticky airborne
substances that can be deposited on the system’s
electronic and mechanical parts. Besides contributing
directly to system degradation, viscid contaminants
collect and hold particulate contaminants and make
cleaning very difficult. Viscid contaminants can be
removed from the air by filtration, but the elimination of
their source, if possible, is preferable.
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