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A clean room is a work area with controlled temperature and humidity to
protect sensitive equipment from contamination. It contains plastic walls
and ceilings, external lighting, and there is a continuous influx of clean,
dust-free air. The room should be cleaned daily to prevent contamination.
Many different industries require the use of a clean room. Medical facilities,
integrated circuit manufacturers, and dairy farms are just a few. Most data
recovery labs at least have a class 100 or better clean room to perform
even the most basic recovery procedures. Any physically damaged hard disk,
for instance, must be recovered in a clean room. Without a clean room, contaminants
can settle on the platters. After a hard disk platter has become contaminated,
the heads can catch on these particles, more or less sanding the platter
surface. This can result in data loss.
It is vital that construction of the clean room includes strict control
of the environmental conditions in order to insure a quality
room. The environmental conditions in a clean room are controlled by particle
enclosure during installation of the wall, floor, ceiling and media. Later,
particle sources cannot be easily removed and the particles could cause
contamination.
The equipment used in a clean room environment depends on the level of
cleanliness required. In industries where a specific level of cleanliness
has been established, the Federal Standard STD-209E form is used. This standard
outlines the airborne particulate cleanliness classes. Class limits are
given for each class name. These limits designate specific concentrations
(particles per unit volume) of airborne particles found in the clean room.
Federal Standard 209E Airborne Particulate Cleanliness
Classes
| class |
maximum number of particles
per cubic foot of air
of diameter greater than or equal to
each indicated size |
typical
uses |
| 0.1 µm |
0.2 µm |
0.3 µm |
0.5 µm |
5.0 µm |
| 1 |
35 |
7.5 |
3 |
1 |
— |
- integrated circuits manufacturing
|
| 10 |
350 |
75 |
30 |
10 |
— |
| 100 |
— |
7502 |
300 |
100 |
— |
- hard drive manufacturing
- hard drive data recovery
- miniature ball bearings assembly
- photo labs
- medical implants
|
| 1000 |
— |
— |
— |
1000 |
7 |
- pharmaceutical manufacturing
|
| 10000 |
— |
— |
— |
10000 |
70 |
- color TV tubes
- hospital operating room
|
| 100000 |
— |
— |
— |
100000 |
700 |
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A shell encloses the clean room, separating the clean air from the rest
of the building. The shell is ventilated with filtered air during construction
to prevent contamination. Another risk factor is leakages in the system.
To help guard against this, the Filter Fan Concept aids in the re-circulation
of about 96% of the total air volume within the clean shell and also ensures
high flexibility.
Clean rooms must be controlled and monitored very closely during construction,
start-up, and operation. Extensive measuring and testing must be done periodically
to ensure that the clean room is running properly.
Clean room operators are required to wear special non-linting body-suits,
overshoes, gloves, head coverings and masks. In some clean rooms, workers
even pass through an air blast upon entering to remove particles and ensure
minimal contamination of the environment.
All of ESS Data Recovery clean-rooms and clean-flow benches are certified
every 6 months to meet NEBB Clean-room standards.
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