FILTRATION.
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| Any ductless fume
hood pretending to comply with a filtration standard (especially
the most demanding one, the AFNOR NF X 15-211 standard) should
be equipped with an electronic monitoring system for the
filter saturation associated with an alarm and/or sampling device
for periodical detection of filter saturation checks. |
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MOLECODE DETECTOR
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SAMPLING PORT FOR PERIODIC MEASURE
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There is no universal
detection method of filter saturation. Only solvents can
be detected electronically.
Beware of hoods which
are always equipped with an electronic detector : they
might cost you more without offering you a genuine protection. |
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| For a frequent use
of the ETRAF, or if you plan to handle large quantities of chemicals,
your ductless fume hood should be equipped with a back-up safety
filter, to prevent any risk of chemical exhaust within the room
when the main filter becomes saturated. |
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SAFETY BACK-UP FILTERS, ON A captair® TOXICAP
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| For a periodical
use of the ductless fume enclosure, or if you plan to handle
smaller quantities of chemicals, your ETRAF should be equipped with an hour counter, which rings every 60 working hrs. to
remind the user of the need to conduct a filter saturation test. |
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| TIMER |
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VENTILATION.
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| If you want to be
sure that the fan of your ETRAF functions properly, your ductless
fume hood should be equipped with a continuous ventilation
monitoring system associated to an audible and visual alarm in case of a fan breakdown. |
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FAN FAILURE |
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THE CONTAINMENT EFFICIENCY OF THE ENCLOSURE.
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| The containment
efficiency concerns the ability of the enclosure to prevent
dangerous and odorous chemicals from escaping through the front
opening where the user is located. According to the latest containment
standards (XP X 15 203, DIN 12 927, BS 7258), a maximum of
0.1 ppm (French standard) and of 0.5 ppm (German standard )
of a given chemical (SF6) can be released through the front
opening. |
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Invent UK TEST REPORT
CONTAINMENT ON captair® TM ETRAFs < 0.05 ppm |
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Beware of the ductless
fume hood manufacturers who imply that containment efficiency
also includes filtration efficiency.
Filtration and containment
are two very different matters and it is much easier to
comply with containment standards than with filtration
standards. |
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THE AIR FACE VELOCITY.
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| The average air
face velocity is not essential as long as the ductless fume
hood complies with the containment requirements. Nevertheless
the AFNOR NF X 15-211 standard requires that the average
air face velocity be maintained between 0.4 m/s and 0.6 m/s. |
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| AVERAGE AIR FACE VELOCITY OF ALL captair® ETRAFS :
0.50 m/s. |
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