TARGAS-1 Operation Manual V. 1.02
80
CPY (Canopy Assimilation Chamber) Process
This process is used in conjunction with our CPY-5 Canopy Assimilation Chamber for measurement of
closed-system net canopy CO
2
flux. In the CPY process, the assimilation rate
(μmol m
-2
s
-1
) is calculated
by measuring the rate of change (decrease) in the chamber CO
2
concentration. The TARGAS-1
calculates both a linear fit and a quadratic fit to the measured data. The data is checked in the quadratic
fit to determine if the data is linear.
While the TARGAS-1 is in the CPY measurement mode, additional data is added to the output data
string: change in CO
2
(dC), process time (dT), Linear respiration rate (L), and Quadratic respiration rate
(Q).
Connecting the CPY-5 Canopy Assimilation Chamber to the TARGAS-1
The CPY-5 Canopy Assimilation Chamber has one electrical
connection and two pneumatic connections. The electrical
connection is made to the socket labeled
PLC
on the
TARGAS-1 and the pneumatic connections are to the
GAS
IN
and
GAS OUT
connectors as shown here. The tubing on
the CPY-5 is labeled accordingly for gas connections. An air
filter is also included on the
GAS IN
line on the CPY-5. For
best results we also recommend using the H
2
O equilibrator
(Part No. 10049-2) on the
GAS IN
line as shown to assist
with reducing the build-up of humidity in the gas stream.
CPY – Start Process (Step 1)
The first screen asks the user to confirm that they would like to start the CPY process.
