Omron ZN-A Series User Manual

45
ZN
System Manual
Section 3 BASIC KNOWLEDGE OF CLEAN SENSING SYSTEMS
Section 3
Clean Sensing
What is "Cleanliness?"
Cleanliness is expressed by the size, number and weight of polluting substances (dust,
dirt, etc.) contained in a fixed area or volume. The degree of cleanliness that is
indicated by the amount of dust or dirt contained in specific air is called the "cleanliness
level." This is further broken down into classes called "cleanliness class."
■ Cleanliness Standards
Standards that relate to the cleanliness of clean rooms, for example, include Fed-Std-
209D in the United States and JIS B 9921 in Japan. The unit volume and particle
diameter of polluting substances that the criteria for these standards are based on are
different. The ZN series adopts cleanliness annotation that complies with Fed-Std-
209D, the most widely used standard at production sites.
■ Definition of Cleanliness According to Fed-Std-209D
Cleanliness is defined by the number of particles of 0.5 µm or more in diameter that are
contained in 1 cubic foot (28.3 liters or approximately a 30 cm cube) of air, and is
broken into classes defined by multiples of ten. This classification is intuitive and easy-
to-understand, and has been used the longest at production sites.
Class
1
Class
10
Class
100
Class
1,000
Class
10,000
Class
100,000
Number of
particles of
0.5 µm or
more/cf
1 10 100 1,000 10,000 100,000
1 max.
→ Class 1
100 max.
→ Class 100
10,000 max.
→ Class 10,000
1f
(approx.
30 cm)
1f
(approx.
30 cm)
1f
(approx.
30 cm)
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Omron ZN-A Series Specifications

General

Brand	Omron
Model	ZN-A Series
Category	Accessories
Language	English