Shutter Fluorometer

Aquation’s Shutter Fluorometer measures both the effective and maximal quantum yield of chlorophyll fluorescence using the “PAM” method. By use of its novel shutter mechanism, a photosynthetic sample (e.g. leaf, algal thallus) can alternately be exposed to full sunlight or be placed in darkness, without user intervention. The flexible software enables yield measurements, dark acclimations, light curves, induction cures, recovery curves and other user-defined actinic light treatments (including far red light) to be made at any time of the day.

The Shutter Sensor is designed as part of a fully submersible fluorometer system for use in marine and freshwater environments. When multiple Shutter Sensors are combined with a Submersible Datalogger, the “Multichannel Shutter Fluorometer” will conduct multi-day deployments on multiple replicate samples.  Regular measurements of photosynthetic activity can now be made after a single set-up dive.  This is particularly useful when an understanding of seagrass or macroalgal photosynthetic performance is needed, yet multiple dives are costly or potentially dangerous.  The Shutter Fluorometer is also well suited to work on land.

Aquation’s Shutter Fluorometer technology derived from work with the Australian Antarctic Division, where a multichannel prototype fluorometer was developed and deployed in Antarctic waters in 2002 (Runcie and Riddle 2004, 2006), and automated Shutter Sensors deployed in 2006 (Runcie and Riddle 2011, 2012).  The rugged build is designed for divers.  Since these initial studies with the Australian Antarctic Division, Aquation has improved the design for reliable operation underwater, and developed user-friendly software.  Our automated dark-acclimation technology is the first, and we think still the best.

Download the Shutter Fluorometer Application note:

Shutter Fluorometer, application note 18Dec17


Shutter Fluorometer

Shutter Fluorometer Sensor and Submersible Datalogger


Shutter Fluorometer measuring wheat photosynthesis at Narrabri

Shutter Fluorometer Sensor, Wheat Trials, Narrabri NSW


Aquation Shutter Fluorometer Triple Channel

Aquation Shutter Fluorometer Triple Channel

Shutter Fluorometer Triple Channel,  Extended Duration Submersible Datalogger.  COST Action, Corsica Oct2011

Download the Shutter Fluorometer brochure:

Aquation Shutter Fluorometer Brochure 21Sep17b

* You will need Acrobat® Reader to view the download.

See the Shutter Sensor in action:  Movie: Shutter Fluorometer and macroalgae


  • Self-closing shutter for automated dark acclimation at any time,
  • Shutter enables automated RLCs and determination of NPQ relaxation,
  • Fully waterproof and rugged design for diving,
  • Easy to use switch initiates program underwater,
  • Autogain and autozero functions automatically establish correct settings in the field,
  • Battery powered (larger housing and battery pack available for extended deployments),
  • Shutter sensor can be operated direct from PC for pre-field tests,
  • Easy-to-use software with an uncluttered interface,
  • Extensive programmable capacity in software for advanced users,

Instrument Features and Specifications:

  • Measures F/Fm’ and Fv/Fm for “PAM” measurements
  • Measures F using shutter, enabling calculation of NPQ components
  • Provides far-red illumination for PSI activation
  • Provides actinic light for rapid light curves, induction curves or custom irradiance treatments
  • Separate logger can operate 1 or 3 sensors simultaneously
  • Select programs provided or define your own program using easy-to-use software
  • Autonomous operation for up to 72 h depending on program
  • Fully waterproof to 50m depth; also suitable for terrestrial use
  • Mechanically driven shutter darkens sample on command while maintaining water movement
  • Measures temperature and PAR; cosine-corrected irradiance sensor on measuring head
  • 316 stainless steel

Please use the Contact Form to make further enquiries.