AP4 Leaf Porometer
Direct readout of stomatal conductance or stomatal resistance of leafs
Simple absolute calibration in the field
Minimises leaf stress during measurement
Ideal for phenotyping based research
Award-winning user interface
Stomatal aperture is the dominant factor in the diffusion conductance of leaf surfaces, which controls both the water loss from plant leaves and the uptake of CO2 for photosynthesis. Measurements of diffusion conductance are therefore important indicators of plant water status and provide a valuable insight into plant growth and plant adaptation to environmental variables.
AP4 Leaf Porometer features
The AP4 Leaf Porometer measures diffusion conductance by comparing the precise rate of humidification within a small cuvette to readings obtained with a calibration plate. The plate has 6 diffusion conductance settings whose values have been accurately determined by finite element analysis.
Quoted accuracy figures for other porometers and gas analysis systems are based on time-consuming laboratory set-up and calibrations which bear little comparison to field conditions. In contrast, the AP4 Leaf Porometer features simple direct calibration in the field against a tested physical standard.
The AP4 Leaf Porometer has many other features designed to ensure that accurate, reproducible readings can be taken as easily as possible:
Sophisticated temperature compensation
Unstirred leaf chamber minimises unwanted stomatal closure
Lightweight ergonomic sensor head
Large clear LCD display (8 lines by 40 characters)
Full QWERTY keypad for annotating up to 1500 readings
A rugged and reliable tool for phenotyping projects
Over 2,000 Delta-T porometers in use worldwide
Porometer design collaboration with Prof John Monteith
Delta-T Devices worked closely with Professor John L. Monteith (1929 - 2012) over a period of four decades - from manufacture of the world's first automatic porometer in the 1970s, through several subsequent versions - leading to the current AP4 Porometer.
Delta-T Devices Founder, Ed Potter, shared a platform with a number of speakers to pay tribute to Professor John L. Monteith at the 2013 American Society of Agronomy Annual Meeting in Tampa, Florida. The talk included a history of the development of the automatic porometer.