Zero Air Generator
4
Velcro
®
strap
A Velcro
®
strap is used as a lanyard to secure the Zero Air Generator to a
crossarm or other support when it is used in the field. If this strap is lost or
damaged it can be replaced with pn 4180, which is a 30 cm (12 in) length of
2.5 cm (1.0 in) wide Velcro
®
with a plastic loop. Longer or shorter straps are
also available. Contact Campbell Scientific for details.
5. Specifications
Dimensions
Length:
14.0 cm (5.5 in)
Width:
9.6 cm (3.8 in)
Height:
27.4 cm (10.8 in)
Weight:
1.16 kg (2.55 lb)
Operating temperature range:
−
20 to 50 °C
Capacity:
750 ml (holds approximately 450 g
molecular sieve)
Flow rate:
0.2 LPM (typical)
Power:
two AA batteries
6. Operation
6.1 Theory of Operation
In normal operation, ambient air enters the Zero Air Generator through an
In
port on the front of the module, flows through an inline filter, and is pushed by
a small pump into the top of a bottle containing molecular sieve. The
molecular sieve removes the CO
2
and water vapor from the air as it flows down
the length of the bottle. Scrubbed air enters a tube at the bottom of the bottle
and then emerges from the
Out
port at the front of the module.
The
Test
port provides scrubbed air pulled from the middle of the molecular
sieve, whereas the
Out
port has zeroed air removed from the bottom of the
molecular sieve. See FIGURE
for the configuration of the ports.