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Principle of Operation Samples,
digested and acidified, contained in test
tubes are set into the 50-positions Sample
Changer. The Bubbler moves to the assigned
sample position and seals up. Reducing
reagents (SnCl2 and H2SO4) are automatically
added to the sample and rapidly aerated.
Reduced mercury is transferred via the
dehumidifier (trapped all water vapor) and
only dry Hgo enters the absorption cell to
measure at 253.7nm. Measured Hgo is trapped
in an exhaust filter before venting back to
the ambient as zero-air. Bubbler moves to
Rinse Station for flushing with distilled
water before commencing the next reduction.
The operation of RA-3000 requires no special-grade bottle
gas (just ambient air) as carrier for purge gas even down to 1 ppt detection
limit, which makes the setup simpler and economical long-term operation.
RA-3000 operation is in compliance with the following
methods:
USEPA - 245.1, 245.2 245.7, 7470, 7471 and etc |
