The AP4 measures the stomatal conductance of plant leaves quickly

and easily.  It is a highly practical instrument for field work, being

based on the cycling diffusion principle, which makes it possible to

have a lightweight sensor head (130g) and to run quick calibration

checks in the field.  The sensor head design minimises leaf stress

during measurements.  The award-winning user interface makes

the operation of the AP4 logical, easy to learn and convenient.

*Direct readout of conductance or resistance

*Simple and rapid calibration in the field

The PMR-5 is a steady-state, continuous flow prorometer designed

to be used with the EGM-4 CO2 analyzer.  The EGM-4 supplies the

power (internal, rechargeable, 12V battery), measures the outputs

from the porometer sensors, processes the results and the displays

and records the data.  The PMR-5 is a hand-held unit using an

"open system" measurement of leaf transpiration.  There is a

mass-flow controlled air supply integrated in the cuvette with

manual control of humidity up to ambient.  The lightweight cuvette

is designed to couple the leaf to the ambient temperature using

a fan, heat sink and radiation shield.  There is a stirring fan in

the chamber to minimize the booundary layer resistance.  Digital

humidity and temperature sensors accurately monitor the air

entering and leaving the cuvette.  There are closely situated in

the chamber with tortuous air paths to minimize the temperature

difference between sensors.  A sensor matching process eliminates

errors due to sensor imbalance.

The CIRAS-2 is the most advanced system on the market today.

All features are fully integrated into a field portable, lightweight

package.  The system has a high technical specification making

it an ideal choice for the most demanding leaf gas exhange

sdudies in the laboratory, yet it is robust and reliable for field

studies.  A wide range of cuvettes and chambers are available

for leaf, canopy and soil studies, spot measurements or analysis

of long term changes in gas flux.

*Lightweight and truly field portable

*Open & closed system measurements

*Automatic control of CO2, H2O, temperature and light

*Auto-Zero and self-calibration checking facility

*Wide range of standard cuvettes and light units for signal

  leaves, canopies and soil analysis