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Underwater Fluorometer with Miniature Spectrometer



The DIVING-PAM-II is a submersible chlorophyll fluorometer designed for in situ measurements of photosynthetic performance in aquatic environments. Based on the pulse-amplitude modulation (PAM) principle, the system measures chlorophyll fluorescence directly underwater — preserving natural conditions and eliminating the need for sample collection.
Key fluorescence parameters are automatically determined from saturation pulse analysis, including quantum yield, maximum quantum yield (FV/FM), or non-photochemical quenching (NPQ). A far-red LED enables specific excitation of photosystem I (PSI). Built for demanding marine and freshwater fieldwork, the DIVING-PAM-II is the instrument of choice for coral reef monitoring, seagrass ecology, aquaculture, and underwater photosynthesis research.
A defining feature of the DIVING-PAM-II is its integrated miniature spectrometer, the MINI-SPEC. It measures the spectral composition of photosynthetically active radiation (PAR) at the measurement site and automatically calculates total external PAR — a critical parameter, as light quality changes significantly with water depth. The miniature spectrometer also enables spectral analysis of fluorescence emission and reflectance for species identification and physiological characterization.
The depth-rated, fully submersible housing is built for reliable SCUBA-based fieldwork. Ten waterproof infrared reflection switches and a transflective display ensure intuitive operation underwater. Built-in sensors log depth and temperature with every measurement, while a proven fiberoptics system allows precise positioning on corals, macroalgae, and seagrass leaves.
The internal flash memory stores over 27,000 measurements, with convenient data download via wireless LAN. For long-term monitoring, underwater cables connect the DIVING-PAM-II to a Windows computer running the WinControl-3 software. In dry environments, the system also operates accessories of the MINI-PAM-II fluorometer.
The DIVING-PAM-II is widely used by marine biologists, coral reef ecologists, and environmental scientists to study photosynthetic performance in aquatic ecosystems. Typical applications include for example:
The DIVING-PAM-II is available in two versions optimized for different sample types: The DIVING-PAM-II/B (BLUE Version) uses blue measuring light at 475 nm with broad fluorescence detection above 630 nm. The DIVING-PAM-II/R (RED Version) uses red measuring light at 655 nm with fluorescence detection above 700 nm.



