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AP4 Porometer

Updated:2025-03-13

Brand: Delta-T
Model: AP4
Description: 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 d
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Product Details

AP4 Porometer Description：

User's Manual Technic Manual Datasheet

Direct readout of stomatal conductance or stomatal resistance

Simple absolute calibration in the field

Minimises leaf stress during measurement

Ideal for phenotyping based research

Award winning user interface

5 year warranty

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 (chamber) 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

AP4 Porometer Specification：

Parameter	Reading range	Resolution [1]	Accuracy [2]	Test conditions [5] Reading range
Conductance	5.0 -1200 mmol m^-2 s^-1	0.1 – 10	± 10 %	5 – 800 mmol m^-2 s^-1
Conductance	5.0 -1200 mmol m^-2 s^-1	0.1 – 10	± 20 %	800 – 1200 mmol m^-2 s^-1
Conductance	0.25 – 30.0 mm s^-1	0.01 – 0.1	± 10%	0.25 – 20 mm s^-1
Conductance	0.25 – 30.0 mm s^-1	0.01 – 0.1	± 20 %	20-30 mm s^-1
Resistance	0.2 – 40 s cm^-1	0.01 – 0.1	± 10 %	0.5 – 40 s cm^-1
Resistance	0.2 – 40 s cm^-1	0.01 – 0.1	± 0.2 s cm^-1	0.2 – 0.5 s cm^-1
RH	0 – 100%	0.1	± 4%
Cup temp	-5 – +55 °C	0.1	± 0.7 °C	0 – 50 °C
Cup-leaf temp	5 – +5 °C	0.1	± 0.2 °C	0 – 50 °C
PAR flux [3]	0 – 2500 μmol m^-2 s^-1	10	± 15%
Pressure [4]	600 – 1200 hPa, settable in steps of 5 hPa
RH cycle level	20 – 80 %RH, settable in steps of 5%