Safety System - Thermo Scientific MSC-Advantage Operating Instructions Manual

Operating Instructions Biological Safety Cabinet | MSC-Advantage
4 Description of the device
4.2

Safety system

The safety system comprises a combination of protective and alarm systems
that ensure maximum personal and material protection.
Safety systems:
• Vacuum-sealed air system
A vacuum-sealed air system in combination with HEPA filters for downflow
and exhaust air forms the basis of the safety system for personal and ma-
terial protection.
• Personal protection
Air aspired from the exterior along the entire working opening at a constant
high velocity prevents:
• agents leaking through the working opening of the chamber.
As the exterior air pressure around the device exceeds the pressure of the
internal air system (vacuum sealing), it ensures:
• agents cannot be released to the exterior in the case of a leak in the
cabinet housing.
• Material protection
A steady airflow within the air system ensures:
• a constant downflow allowing the HEPA filters to remove contaminants
so that the samples are always surrounded by ultrapure air,
• harmful particles are not carried over through the sample chamber
(protection from cross-contamination).
• HEPA filters
The downflow (i.e. the air circulating within the device) and the exhaust air
(air that is released to the exterior) are cleaned by HEPA filters (HEPA = High
Efficiency Particulate Air Filter).
• Safety lockout
To protect from UV radiation, the optional UV disinfection routine can be run
only if the front opening is closed. During UV disinfection, the front opening
safety lockout is activated and prevents harmful UV radiation from being
emitted from the sample chamber.
Circuits can be driven via potential-free contacts (monitor contacts), e.g. a
solenoid that switches automatically upon cancellation of the work mode.
Warning system:
• Airflow monitoring
Airflow monitoring determines the velocity of the airflow in the sample chamber
as well as the inflow velocity of the air aspired from the exterior through the
working opening. As soon as airflow velocities move above or below a spe-
cified safety value, a signal is transmitted to the alarm system.
• Visual and audible alarm system
The warning system constantly monitors the safety-relevant device functions:
• Inflow velocity of the air aspired from the exterior,
• downflow velocity,
• work position of the front window.
If the warning system detects changes to one of these device func-
tions, it issues:
• an audible and a visual alarm signal.
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