Campbell 31022, Инструкция по эксплуатации

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Zero Air Generator
2
FIGURE 4-1. Zero Air Generator
The Zero Air Generator makes it easy to zero an IRGA in the field. For open-
path IRGAs, such as the IRGASON or EC150 (sold by Campbell Scientific
®
,
Inc.) or the LI-7500 (sold by LI-COR
®
, Inc.), a zero/span shroud is also
required. For these open-path analyzers, the zero/span shroud is installed and
the Zero Air Generator is connected in either an open- or closed-loop
configuration. The small battery-powered pump in the Zero Air Generator
circulates a low flow through a bottle filled with molecular sieve that removes
CO
2
and water vapor, and pushes it through the zero/span shroud.
The Zero Air Generator may also be used to zero a closed-path IRGA such as
the EC155 (sold by Campbell Scientific
®
, Inc.), or the LI-6262, LI-7000, LI-
7200, or LI-840A (sold by LI-COR
®
, Inc.). Closed-path analyzers do not
require a zero/span shroud.
The Zero Air Generator includes a third connection that allows the user to
assess the status of the molecular sieve. This gives an indication of when to
replace the molecular sieve, ensuring that CO
2
and water vapor are always
completely removed.