# Heinz Walz GmbH > Heinz Walz GmbH invented Pulse Amplitude Modulation (PAM) fluorometry — the global standard for measuring photosynthetic efficiency. Since 1972, our scientific instruments have supported researchers at universities, institutes and government agencies in over 175 countries. Key facts: - Independent, third-generation family business based in Effeltrich, Germany, founded in 1972 - Inventor of PAM fluorometry — cited in more than 80,000 scientific publications at 1,500+ universities worldwide - Direct technical support from application scientists with hands-on expertise in plant physiology ## Products [View all products](https://www.walz.com/products/) PAM chlorophyll fluorometers — measure photosynthetic efficiency from single algal cells to whole canopies: - [DUAL-PAM-100](https://www.walz.com/products/dual-pam-100/): Simultaneous measurement of chlorophyll fluorescence and P700 absorbance changes - [DUAL-KLAS-NIR](https://www.walz.com/products/dual-klas-nir/): Near-infrared analysis of P700, P515, plastocyanin and ferredoxin - [MULTI-COLOR-PAM-II](https://www.walz.com/products/multi-color-pam-ii/): Wavelength-resolved PAM fluorometry with multiple excitation colors - [PAM-2500](https://www.walz.com/products/pam-2500/): Portable high-performance PAM fluorometer - [MINI-PAM-II](https://www.walz.com/products/mini-pam-ii/): Compact field fluorometer for plant ecophysiology - [MINI-PAM-II Porometer](https://www.walz.com/products/mini-pam-ii-porometer/): MINI-PAM-II combined with stomatal conductance measurement - [JUNIOR-PAM](https://www.walz.com/products/junior-pam/): Affordable PAM fluorometer for teaching and basic research - [DIVING-PAM-II](https://www.walz.com/products/diving-pam-ii/): Underwater PAM fluorometer for corals, seagrasses and macroalgae - [WATER-PAM-II](https://www.walz.com/products/water-pam-ii/): PAM fluorometer for phytoplankton suspensions - [PHYTO-PAM-II](https://www.walz.com/products/phyto-pam-ii/): Multi-wavelength PAM for discriminating phytoplankton groups - [MONITORING-PAM](https://www.walz.com/products/monitoring-pam/): Long-term unattended field monitoring of photosynthesis - [IMAGING-PAM](https://www.walz.com/products/imaging-pam/): 2D fluorescence imaging of leaves and other samples - [HEXAGON IMAGING PAM](https://www.walz.com/products/hexagon-imaging-pam/): High-resolution hexagonal imaging fluorometer - [MICROSCOPY-PAM](https://www.walz.com/products/microscopy-pam/): PAM fluorometry at microscopic resolution - [MICRO-PAM](https://www.walz.com/products/micro-pam/): Miniaturised PAM fluorometer - [MICROFIBER-PAM](https://www.walz.com/products/microfiber-pam/): Fibre-based PAM for spatially defined measurements Gas exchange & cultivation systems: - [GFS-3000](https://www.walz.com/products/gfs-3000/): Portable gas exchange and fluorescence system - [Large-scale gas exchange](https://www.walz.com/products/large-scale-gas-exchange/): Whole-plant and branch chambers - [3010-GWK1](https://www.walz.com/products/3010-gwk1/): Compact growth chamber for gas exchange research - [KF-18-2B / KF-24-6B](https://www.walz.com/products/kf-18-2b-kf-24-6b/): Climate chambers - [GMA gas mixing units](https://www.walz.com/products/gma-2-3-4-gas-mixing-units/): Precision CO₂/O₂ gas mixers - [TS-2 dewpoint mirror](https://www.walz.com/products/ts-2-dewpoint-mirror/): Reference humidity measurement - [Bypass humidity control](https://www.walz.com/products/bypass-humidity-control/): Stable humidity for gas exchange systems Light sensors & illumination: - [ULM-500 light meter / logger](https://www.walz.com/products/ulm-500-light-meter-logger/): Universal light meter with data logging - [LS-C mini quantum sensor](https://www.walz.com/products/ls-c-mini-quantum-sensor/): Cosine-corrected PAR sensor - [MQS-B mini quantum sensor](https://www.walz.com/products/mqs-b-mini-quantum-sensor/): Compact PAR sensor - [US-SQS-L spherical micro quantum sensor](https://www.walz.com/products/us-sqs-l-spherical-micro-quantum-sensor/): Underwater spherical PAR sensor - [MC-MQS-OVV microscopy quantum sensor](https://www.walz.com/products/mc-mqs-ovv-microscopy-quantum-sensor/): PAR measurement at the microscope stage - [RGBW-L084](https://www.walz.com/products/rgbw-l084/): RGB-W actinic illumination Leaf analysis: - [LSA-2050 leaf state analyzer](https://www.walz.com/products/lsa-2050/): Non-destructive leaf reflectance and transmittance ## Service & Support - [Technical support](https://www.walz.com/service/support/technical-support/): Direct contact with scientist-application specialists - [Tutorials](https://www.walz.com/service/support/tutorials/): Setup and measurement guides - [Repair service](https://www.walz.com/service/support/repair-service/): In-house repair and calibration - [Downloads](https://www.walz.com/downloads/): Manuals, firmware and software - [Request a quote](https://www.walz.com/service/sales/request-a-quote/) - [International distributors](https://www.walz.com/service/sales/international-distributors/) ## Events - [Webinars](https://www.walz.com/events/webinars/): Online product introductions and method workshops - [Meetings](https://www.walz.com/events/meetings/): International user meetings and conferences ## Company - [About us](https://www.walz.com/company/about-us/): Family-owned manufacturer of photosynthesis instruments since 1972 - [Company founder](https://www.walz.com/company/company-founder/): The story of Heinz Walz and the invention of PAM fluorometry - [News](https://www.walz.com/company/news/): Product announcements and company updates - [Jobs](https://www.walz.com/company/jobs/): Open positions in Effeltrich, Germany - [Legal notice](https://www.walz.com/legal-notice/) - [Privacy policy](https://www.walz.com/privacy-policy/) ## Contact - **Email**: info@walz.com - **Phone**: +49 9133 7765 0 - **Address**: Heinz Walz GmbH, Eichenring 6, 91090 Effeltrich, Germany - [Contact form](https://www.walz.com/service/support/contact/)