CIRAS-3 Operation Manual V. 1.09
142
Thus:
A
V
Ta
P
b
R
*
41
.
22
01
.
44
*
273
273
*
25
.
1013
*
+
=
(3)
Where:
R is the CO
2
flux in kg.m
-2
.s
-1
V is the system volume (largely the chamber volume) in m
3
A is the soil area exposed in the chamber in m
2
, P is the atmospheric pressure in mb
Tc is the temperature of the system volume (chamber) in ºC.
We measure: -
DC/DT = b as ppm/second
V in cm
3
A in cm
2
R is expressed as g.m
-2
.hr
-1
.
To convert (g.m
-2
.hr
-1
) to (micro-mol.m
-2
.s
-1
) multiply by 6.312
References
Parkinson K.J. (1981). An improved method for measuring soil respiration in the field. Journal of Applied
Ecology, 18, 221-228.
Electrical and Pneumatic Connection between the CIRAS-3 and SRC-1 /
CPY-4
In order to use the SRC-1 and CPY-4 with the CIRAS-3, an Auxiliary Probe
Adapter (APA) is required. The APA connects electrically to the CIRAS-3 via
the 4 pin socket labeled “AUX” in the lower left hand corner of the CIRAS-3
console. The SRC-1 and CPY-4 (and STP-1 Soil Temperature Probe if used)
connect to either of the 15 pin sockets on the other end of the APA. The APA
contains electronics that allow the these chambers to interface with the
CIRAS-3 main console. We recommend mounting the APA to the side of the
CIRAS-3 console as shown below using the Velcro supplied.