For an eight port multiplexer connect the pump
outlet with a single section of Bev-a-line tubing to
the lower right hand solenoid manifold.
9. There are two ways to configure the LI-8150 to vent
exhaust from the flasks.
a. Method 1: Dedicate a port on the multiplexer to
supply air to the auxiliary pump and expel
exhaust from the chambers.
i.
Disconnect the two urethane hoses
coming from one set of port connections on
the side of the LI-8150 from the solenoid
manifolds.
ii. Insert 1/4 inch quick connect plugs (part
#300-08151) into the open fittings on the
solenoid manifolds (Figure 8).
iii. Connect the urethane hose from the “IN”
connection of the port to the inlet of the
auxiliary pump using a quick connect
straight union.
iv. For a sixteen port model install a quick-
connect “Y” fitting (part #300-03367) on the
end of the “OUT” hose. For an eight port
multiplexer, install a quick connect straight
union (part #300-03123) on the “OUT” hose.
v. Cut two 35.5 cm lengths of Bev-a-line
tubing and connect the upper manifolds to
the “Y” fitting with each length of tubing.
For an eight port model use one length of
tubing to connect the upper right hand
manifold to the “OUT” hose.
b. Method 2: If dedicating a port to vent chamber
exhaust and supply air to the auxiliary pump is
undesirable, the supply/exhaust lines can be
routed out of the LI-8150 by leaving the case
open. If using this method, a filter (part #301-
08119) should be added before the pump inlet.
Constructing chambers
Flasks can be constructed from any gas tight containers,
provided they meet the volume considerations discussed
above and can be fit with connections for the LI-8150. Be
careful with plastic containers as sorption of water vapor
(and possibly CO
2
) by the container may affect the
measured fluxes. Here we describe how to use 1.89 L
glass canning jars (Ball Corporation, Daleville, IN) as
sample chambers.
1. With the lid removed from the jar, drill one 12 mm
hole off center in the lid. Drill two 8 mm holes on
Figure 8.
A sixteen port multiplexer configured for flask measurements. Port 16 has been re-purposed to vent flask exhaust
from the LI-8150 case and supply ambient air to the pump.
9981-108 power cable in an
unmodified multiplexer
To disconnect power to the pump,
unplug this connector
Exhaust lines
Install plugs (300-
08151) in the open
connectors on the
solenoid manifolds
Connect the exhaust
lines to the “out” line
from one of the ports
using part #300-03367
Connect the “in” line
from the same port
to the inlet on the
auxiliary pump
Ambient air line
from pump
Pump
6
