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Quality Instrumentation for the Life Sciences
Slide backgroundCIRAS-4 Portable Photosynthesis System

Unrivaled Performance,

Portability & Power.

Portable Photosynthesis System

The 4th generation system that continues

to elevate the research experience.

CIRAS-4 Redefining the high-level field research experience

CIRAS-4 Portable Photosynthesis System

Don’t let its compact size fool you.

The highly accurate CIRAS-4 Portable Photosynthesis System is a lightning-fast portable powerhouse that will elevate your research experience.

Its advanced software is exceptionally intuitive and customizable. You can manage environmental controls—as well as how you view your data—all from the touchscreen.

It’s so easy to use, you can begin taking measurements right out of the box.

An exceptional user experience

Minimal Size. Maximum Performance.

The CIRAS-4 is designed with the high-level field researcher in mind. Its small size makes it the most portable photosynthesis system of its kind, alleviating the need for assistance or tripods.

The innovative design of the CIRAS-4 utilizes its small system volume to ensure faster equilibration as well as the most rapid and accurate measurements available. Faster measurements allow the user to expand the parameters of their research and use their time and resources efficiently. Check out the size and weight of the CIRAS-4 console and leaf cuvettes and you will quickly discover why smaller and lighter is better.

high contrast touchscreen

The CIRAS-4’s full-color touch display offers fast-response touch navigation for all system operations. Exceptionally bright LEDs are adjustable for sunlight readability in any condition.

lightweight leaf gas exchange system

True differential analyzer for the ultimate accuracy & reliability.

The heart and soul of any photosynthesis system is the analyzer. Accurate, reliable, and stable measurement and control of CO2 and H2O are critical for high-level research. A “true differential analyzer”, the CIRAS-4 features 4 independent, non-dispersive gas analyzers for accurate, simultaneous measurement and control of both CO2 and H2O — a significant advantage over “gas switching” systems and a major requirement for most researchers. The analyzers act as absorptiometers measuring infrared absorption only. The temperature-controlled optical bench is pressure compensated ensuring the most accurate measurement of CO2 and H2O under changing ambient conditions.

Packed with power.

The CIRAS-4 comes standard with three (3) rechargeable Li-ion battery packs that provide 16+ hours of continuous operation. All 3 batteries can charge simultaneously allowing the user to collect lots of data without the interruption of swapping out battery packs. 

CIRAS4 Battery Status

Fast Response. Fully Mobile.

The location of the CIRAS-4’s IRGAs (Infrared Gas Analyzers) in the main console — right next to the internal gas mixing system and flow control — allows the CIRAS-4 to provide an ultra-fast response to changes in “reference” gas, and the fastest and most accurate portable photosynthesis measurement available. IRGAs in the console makes the entire system highly portable, not to mention the added protection from dirt, dust, and debris commonly found in and around a leaf cuvette.

PLC4 Leaf Cuvettes

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Lightweight. Fast. Precise.
• Head plates secured with magnets - no tools needed!
• Automatic temperature control
• Airtight seal without damage to vegetation
• Fastest response to CO2 and H2O changes
• Optional LED Light Unit (RGBW-FR)
• Minimal boundary layer resistance
PLC4 Universal Leaf Cuvette shown.
PLC4 Universal Leaf Cuvette

No tools required.

Head plates are secured in place by magnets for quick and easy change out in the lab or field.

Rulers on apertures.

Rulers are available on larger head plates to assist with better leaf area approximation.

PLC4 Leaf Cuvette Rulers
Changing head plates is quick and easy

Minimal boundary layer resistance.

Advanced air mixing inside the chamber reduces boundary layer resistance.

Temperature control

All PLC4 Leaf Cuvettes offer a temperature control range of approximately 12°C below ambient up to 15°C above ambient with 0.1°C precision.

Easy and accurate leak diagnosis.

Direct pressure measurement inside the cuvette for easy and accurate leak diagnosis.

PLC4 Universal Leaf Cuvette

The PLC4 Universal Leaf Cuvette comes with three interchangeable head plates and is compatible with the CFM-4 Chlorophyll Fluorescence Module for simultaneous measurement of leaf gas exchange and chlorophyll fluorescence.

25 mm x 18 mm
25 mm x 7 mm
18 mm diameter

PLC4 Broad/Narrow/Conifer Leaf Cuvette

Broad: 30 mm x 30 mm

The PLC4 Broad/Narrow/Conifer Leaf Cuvette comes with three interchangeable heads for measurement on large, flat broad leaves, narrow leaves, and grasses and conifers. 

Narrow: 86 mm x 37 mm
Conifer: 76 mm x 36 mm

PLC4 LED Light Units (RGBW-FR)

PLC4 LED Light Unit

Automatic control.

Optional light units are available for automatic control of light for all PLC4 leaf cuvettes. Each light unit features a bank of red, green, blue, and white LEDs, allowing for automatic control of both light intensity up to 2500 μmol m-2 s-1 and proportion of light by wavelength. All light units are designed to ensure uniform light distribution over the entire leaf area for accurate results.


Our PLC4 leaf cuvettes also include 4 far-red LEDs (730 nm +/- 5 nm). CIRAS-4 users will be able to control far-red up to 30% of PAR, allowing users to more accurately recreate the natural light environment.

Why is far-red important?

Far-red photon flux (700-750 nm) is about 18% of the PAR (400-700 nm) photon flux in sun light, and far-red makes up an even larger fraction of the photon flux in understory conditions. Recent research has shown that this far-red light is photosynthetically active. Taking photosynthesis measurement with a light spectrum that does not include far-red (e.g., white or red/green/blue LEDs) will result in lower photosynthetic rates compared to photosynthetic rates under sunlight (with the same PAR). Being able to control the amount of far-red light during photosynthesis measurements will more accurately mimic rates under sunlight or understory conditions.  CIRAS-4 users will be able to control far-red up to 30% of PAR, allowing users to more accurately recreate the natural light environment.

CFM-4 Chlorophyll Fluorescence Module

CFM-4 Chlorophyll Fluorescence Module

Simultaneously measure photosynthesis & chlorophyll fluorescence.

The CFM-4 Chlorophyll Fluorescence Module is capable of both independent measurement of chlorophyll fluorescence as well as simultaneous measurement of photosynthesis and chlorophyll fluorescence.

MultiPulse™ Technology for Accurate Estimation of Fm’

The CFM-4 is capable of delivering high-saturating pulses up to 10000 µmol m2 s-1 which is extremely useful in accommodating a wider range of ambient light conditions. The CIRAS-4 is the only system available that features our innovative MultiPulse™ technology.

MultiPulse™ produces a sequence of user-defined, lower-saturating pulse light levels, avoiding the risk of photodamage to the leaf while accurately estimating apparent Fm‘.

A pulse-amplitude-modulated (PAM) fluorometer, the CFM-4 provides both dark- and light-adapted chlorophyll fluorescence measurement parameters including photochemical vs. non-photochemical quenching and electron transport rate.

OJIP fast induction kinetics

The CFM-4 provides OJIP fast induction kinetics as well as multiple additional relevant chlorophyll fluorescence parameters. OJIP-related data are easily stored and exported for further analysis to provide many additional fluorescence-related calculations.

A multi-use accessory!

The CFM-4 is elegantly designed with all light sources and fluorescence detection capability built directly into one lightweight, compact unit. The CFM-4 is a pulse-amplitude-modulated (PAM) fluorometer that can also act as an actinic light source for leaf gas exchange as well as a stand-alone fluorometer when leaf gas exchange data is not required.

Automatic control

The CFM-4 offers automatic control temperature and light intensity (0-2500 µmol m-2 s-1) as well as ratio of red/green/blue/white LEDs, and far-red (0-30% of PAR).

The CFM-4 Chlorophyll Fluorescence Module is an optional accessory designed exclusively for use with the PLC4 Universal Leaf Cuvette.

Advanced intuitive software

Advanced touch navigation & outstanding readability.

The CIRAS-4 offers highly responsive advanced touch navigation for all system operations from its large, full-color sunlight-readable touchscreen offering unsurpassed readability even under high sunlight conditions.

Measurements in minutes

Got a question? Built-in system help and user tutorials are designed to guide even the most inexperienced user every step of the way. technology.

Your data your way

It’s all about the data. Not only can you trust the CIRAS-4 to provide highly accurate data quickly, you can customize your entire data collection and research experience all from the touchscreen.

Data files and comments that are uniquely yours

Create your own unique file names using letters, numbers, and symbols, and adding comments for further detail is quick and easy.

alphanumeric onscreen keyboard

Choose how you view your data

Graph up to six parameters at a time including zoom, pause, and resume, and easily customize the X and Y axis for each parameter.

Graph up to 6 parameters at once
easy-to-use software

Unique multi-user profile system

Set up to eight unique profiles based on application, user, experiment, etc.—very useful when multiple users share a single system.

multi-user profile screen

Stability criteria

Set your own stability criteria for up to 12 parameters to alert you and the system when measurements are stable and ready to record.

stability criteria