PP Systems CIRAS-2 User Manual

System Setup and Operation
CIRAS-2 Operator's Manual Version 2.04
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Analysis Flow
This is the flow rate through the analyzer sample cells. Refers to the rate at which the analyzer samples
the analysis air and is user adjustable between 50-100 cm
3
min
-1
. For normal leaf gas exchange the
recommended operational flow rate is the default setting (100 ml min
-1
).
Averaging Limit
Outputs from CIRAS are subjected to an averaging process. The linearized current reading is differenced
with a stored average reading. If the difference exceeds the Averaging Limit then the current reading
replaces the average, otherwise the current reading is incorporated into the average. The default
Averaging Limit is 30 units, corresponding to 3 ppm for CO
2
and 0.2 mb for H
2
O. If set to 1, averaging is
disabled giving instantaneous readings. The averaging band is increased as the averaging limit is
increased, up to a maximum of 999 units. The Enable Averaging box must be checked.
System Setup
Probe Type
Air Supply On
Checking/unchecking this box turns the internal cuvette air supply unit on and off. Setting the Air Supply
pumps to Off will result in the setting of CO
2
and H
2
O set points being disabled as the flow is assumed to
come from a separate source ( i.e. an external air supply).
Cuvette Flow
Flow rate to the cuvette is dependent upon cuvette type used with CIRAS-2. If „Air Supply‟ is off, the
maximum flow is 2500 ml min
-1
, if „Air Supply‟ is on the maximum is 470 ml min
-1
. Cuvette Flow must
always exceed the analyzer sampling rate by at least 50 ml min
-1
to ensure positive pressure in the
chamber.
Light Type [ _ ]
PAR
Energy Factor
Default light transmission coefficient determined by the Light and Chamber Type. User specified for
custom chambers. Refer to CIRAS-2 Settings for Leaf Cuvettes and Probes on page 152 of this manual.
Check „Use Sensor‟ (on chamber) to measure PAR or enter a value if using an external light source. If
checked, the PAR sensor on the chamber is used to determine PAR (with or without a light unit attached).
Please note: if a PP Systems‟ light unit is used and „Use Sensor‟ is not checked, the light unit will turn off.
This option will be enabled or disabled depending on the Accessory and Light Type selected.
Value
If disabled, CIRAS will use the entered PAR value in its calculations.

PP Systems CIRAS-2 Specifications

General

Brand	PP Systems
Model	CIRAS-2
Category	Measuring Instruments
Language	English