M-PEA
M-PEA Optical Sensor
The optical sensor unit is a robust enclosure designed to incorporate sophisticated electronics which effectively controls all of the light sources and detectors. The M-PEA-1 sensor unit includes a high intensity red actinic source, a far-red light source, the prompt fluorescence detector and the modulated emitter/detector pair for P700+ absorbance measurements. M-PEA-2 additionally includes a high sensitivity delayed fluorescence detector and a detector to measure leaf absorptivity.
All the optics are located behind a quartz window which seals the sensor unit providing effective protection for the optical assemblies against dust, dirt and moisture.
M-PEA-1 Illumination Sources
- Actinic: Focused ultra-bright LED (dominant λ 625nm) with NIR short pass cut-off filter with a maximum intensity 5000 µmols m-2 s-1
- Far-red: Focused ultra-bright LED with long pass filter. Max. intensity > 1000 µmols m-2 s-1
- P700+: Optically filtered pulse modulated 820nm LED. Intensity 0 - 100% in 1% steps.
M-PEA-1 Detectors
- Prompt fluorescence: Low noise, fast response PIN photodiode with 730nm (± 15nm) bandpass filter.
- P700+ fluorescence: Low noise, fast response PIN photodiode with optical bandpass filter.
M-PEA-2 Illumination Sources
As in M-PEA-1 sensor unit.
M-PEA-2 Detectors
As in M-PEA-1 but with the following additional detectors:
- Delayed fluorescence: High sensitivity wideband avalanche photodiode with 730nm (± 15nm) bandpass filter.
- Leaf absorptivity: Low noise, fast response PIN photodiode