The HEXAGON-IMAGING-PAM is the largest chlorophyll fluorescence imaging system from Walz. It measures areas of 20 × 24 cm with up to 1.2 megapixels resolution-— four times the imaging area of the MAXI IMAGING-PAM while maintaining full PAM saturation pulse analysis with highest accuracy. All 17 fluorescence parameters including Fv/Fm, Y(II), Y(NPQ), Y(NO), and ETR are imaged at pixel level.

The flexible housing design accommodates individually potted plants, seedlings in larger plant trays, and flat samples such as harvested leaves or algae in vessels without conversion time between sample types. This makes the HEXAGON-IMAGING-PAM the ideal platform for high-throughput plant phenotyping and screening applications.

Hexagonal LED Panel for Homogeneous Illumination
The name HEXAGON reflects the shape of the individual LED sub-panels. This geometry offers the best possibility to achieve shadow-free, uniform illumination across the entire measuring area with a maximum deviation of ±7% from the mean intensity. Efficient cooling ensures long LED service life and compensates for temperature-driven power changes, opening new dimensions of measurement accuracy.

Far-Red LED Panel for F0' Determination
A dedicated dual-circuit far-red LED panel enables precise F0' measurement. It delivers FR light or FR light with a higher red component, each finely adjustable allowing accurate assessment of the F0' fluorescence level for comprehensive quenching analysis.

Flexible Sample Chamber with Safety Interlock
The housing accommodates diverse sample morphologies: from flat leaf samples and algae in vessels to potted plants and seedling trays. A dedicated Plant Pot Holder (IMAG-HEX/PH) holds 7 cm round flowerpots. An integrated safety shutdown suppresses all high-intensity light pulses when the door is opened during an experiment.

Digital Zoom Without Loss of Sensitivity
After start-up, the system works in 2×2 pixel binning mode (1000 × 1200 pixels). A software zoom function allows focusing on any freely selectable quarter of the measuring area without changing image resolution enabling higher magnification on a smaller area without loss of sensitivity.

The HEXAGON-IMAGING-PAM is fully controlled by the ImagingWinGigE software. Up to 100 areas of interest (AOIs) can be placed and analysed, with automated sample recognition and drag-and-drop positioning. The user can choose between 18 displayed parameters in real-time false-color imaging during the experiment.

Pre-programmed protocols for induction curves and light curves provide easy starting points for beginners. Advanced users can program script files and remote-control the instrument via the software interface. Light calibration is automated via integration with the ULM-500 light meter.

Chlorophyll fluorescence is a very sensitive indicator of photosynthesis. Quantitative information on the quantum yield of photosynthetic energy conversion is obtained by PAM fluorometry and the saturation pulse method. A wide range of photosynthetic parameters can be derived from fluorescence measurements, giving insight into the physiological state of all photosynthetically active organisms, including higher plants, mosses and ferns as well as various types of algae, phytoplankton and biofilms.

With the advance of highly sensitive CCD cameras, followed by modern CMOS type camera chips, together with extremely strong light emitting diodes (LED), development of IMAGING-PAM fluorometers has become possible that not only measure images of chlorophyll fluorescence but are also fully competent in providing all relevant chlorophyll fluorescence parameters, using the saturation pulse method. In this way, images of photosynthetic activity and its spatio-temporal variations can be obtained. In recent years, the trend has increasingly been towards very low-noise CMOS cameras offering high sensitivities. LED technology is also making continuous progress so that high irradiation intensities can be achieved with lower power.