Technical information

SYSTEM SETUP / CALIBRATION
3/31/2008 Rev. 4.3 5-3
in calibrations for Photosynthesis, Transpiration and Stomatal Conductance values. The sensor is
calibrated at the factory, and normally does not need to be recalibrated.
ENTER to select Calibrate ATM Pr
To change the atmospheric pressure (ATM) value, scroll to choose the “Calibrate ATM Pr” under the
“ENTER to select” function. Enter the desired ATM value in K Pa. Press
to accept the entered
value or to abort the process, and continue to another step.
FLOW RATE
Figure 5-0
The CI-340 is capable of maintaining a steady airflow once the unit begins taking measurements.
After the initial warm-up time (one minute), the instrument will generate the entered flow rate to
regulate the accuracy of the measurements. The instrument is capable of automatically controlling the
flow rate from 0.2 ~ 0.999 lpm. Flow rates of 0.3 lpm give increased accuracy to photosynthesis
measurements unless very active leaves are being measured.
The flow meter is calibrated by the manufacturer but can be calibrated again by the user. Suggested
calibration schedule is once every six months. Scroll to choose the “Calibrate flow rate” under the
“ENTER to select” function.
ENTER to select Calibrate flow rate
The instrument will briefly run through stabilizing steps and then ask the user to adjust the flow,
using the
keys for major changes or the keys for minor changes, over steps
from .2 to 1 lpm. For calibration, the flow MUST be measured by the calibrated external flow meter
at the port on the end of the instrument where the leaf chamber plugs in (upper left part as you read
the keypad). For this calibration, the flow rate is measured at the input to the leaf chamber (see figure