Z995 FluorPen PAR includes all the features of the Z990 FluorPen with all the extra options i.e. it measures Ft, QY, NPQ, OJIP, and Light Curve (QY).

In additions,  the FluorPen PAR incorporates an integrated Light Meter for direct digital readouts of Photosynthetically Active Radiation (PAR) in the range from 400 to 700 nm, the span in which plants use energy during photosynthesis.  A modified Z995-D is adapted for use with detachable leaf clips for quick dark adaptation of leaves before the commencement of measurements (10 leaf clips included)

PAR is measured as Photosynthetic Photon Flux Density (PPFD), which is indicated by units of quanta (photons) per unit time per unit surface area. The sensor has a uniform response to photons withing the 400-700 nm waveband. Instant readouts are provided as average values of 20 measurements.

Measured Parameters:

• Ft - continuous fluorescence yield in non-actinic light. Ft is equivalent to Fo if the leaf sample is dark-adapted.
• QY - Photosystem II quantum yield. In a dark-adapted leaf this is equivalent to Fv/Fm. In a light-adapted leaf it is equivalent to Fv‘/Fm‘.
• OJIP – Chlorophyll Fluorescence Induction Kinetics
• NPQ – Non-Photochemical Quenching
• Light Curve – Adaptation of Quantum Yield to Several Different Light Levels
• PAR - Photosynthetically Active Radiation

Measuring light power is adjustable by flash duration; actinic and saturating flashes are adjustable from 0 to 3,000 µmol photons/m2/s.

Herbicide Application:

• Improvement of the effectivity of herbicide application
• Testing of new herbicides
• High reduction of herbicide use

Photosynthesis Research:

• Field measurement
• Mutant screening
• Stress detection

Agronomy and Forestry:

• Mapping by fluorescence parameters
• Nutrient – Fertilizer analysis

Software :

• FluorPen 1.0 software (Windows 2000, XP, or higher compatible*)
• Bluetooth, USB or serial communication
• Real-time and remote control functions
• Export to Microsoft Excel
• GPS mapping plug-in (extra option)

Specifications:

• Measured Parameters: Fo, Ft, Fm, Fm’, Kautsky induction (OJIP), Fast kinetics
• Actinic and Saturating Light: Adjustable from 0-3000 uE
• Measuring Light: Adjustable by duration
• Detector Wavelength: Range PIN photodiode with 697nm – 750nm bandpass filters
• FluorPen Software: Windows 2000, XP, or higher
• Sample Holder: Mechanical leaf clip
• Bios Upgradeable firmware
• Communication:  Bluetooth 1.1 or USB/serial port
• Memory Capacity: Up to 4Mb
• Internal Data: Logging Up to 100,000 data points
• Display: 2 x 8 characters LC display
• Keypad: Sealed, 2-key tactile response
• Keypad Escape Time: Turns off after 5 minutes of no use
• Power Save Mode: Autosleep
• Power Supply: 4 AAA alkaline or rechargeable batteries
• Battery Lif:e 70 hours typical with full operation
• Low Battery Detection: Low battery indication displayed
• Size: 57 x 30 x 120 mm
• Weight: 180 gOperating Conditions: Temperature: 0 to +55ºC; 32 to +130ºF Relative humidity: 0 to 95% (non-condensing)
• Storage Conditions: Temperature: -10 to +60ºC; 14 to +140ºF Relative humidity: 0 to 95% (non-condensing)
• Warranty: 1 year parts and labor

FluorPen data capture screen:Light Curve data capture screen:

NPQ Protocol Includes Five Measurements in Actinic Light and three measurements during dark relaxation.
NPQ_Ln = (FM – FM_Ln) / FM_Ln
NPQ_Lss = (FM – FM_Lss) / FM_Lss
NPQ_Dn = (FM – FM_Dn) / FM_Dn

NPQ data capture screen:

References:

• Fernandez-Marin B. Becerril JM, Garcia-Plazaola JI.  Unravelling the roles of desiccation-induced xanthophyll cycle activity in darkness: a case study in Lobaria pulmonary: Planta 231:1335–1342 (2010)

• Ruiz-Sanchez. M. et al. The arbuscular mycorrhizal symbiosis enhances the photosynthetic efficiency and the antioxidative response of rice plants subjected to drought stress: Journal of Plant Physiology 167(11):862-869 (2010)

• Harding SA et al. Journal of Experimental Botany 60: 3443-3452 (2009)
• Zhang M. et al. : Ecology and Environmemtal Sciences 18 (6): 2272-2277 (2009).
• Kuvykin I.V. et al. Computer simulation study of pH-dependent regulation of electron transport in chloroplasts: Cell Biophysics 54(4):455-464 (2009)
• Woo N.S. Badger MR, Pogson BJ.  A rapid, non-invasive procedure for quantitative assessment of drought survival using chlorophyll fluorescence: Plant Methods 4(27) (2008)

N-Pen Applications:

• Monitoring relative N-content of crops.
• Better nitrogen management in crops and consequent yield enhancement.
• monitoring of  nitrogen use efficiency.
• management of fertilizer applications
• Agronomy research.

N-Pen Sampling

• Simply insert the leaf between the leaf clip and the optical tip.
• N-Pen collects and stores individual readings and calculates the average automatically.
• Readings should be taken on number of different plants of the same species.
• Readings should be taken on the 2nd or 3rd youngest leaf on each plant.
• Readings should be taken from the same location on each leaf (close to the mid part)

N-Pen Reading

• Displayed is the NDGI ratio and the actual % nitrogen for wheat, barley and corn, or relative numbers for other species.
• Nitrogen content in % is calibrated for particular species (wheat, barley and corn calibrations come standard with the N-pen)
• Calibrations for other plant species available soon
• Variety or hybrid differences can affect readings
• Plant diseases, nutrient deficiencies and other kinds of plant stress can also affect readings

Software:

• FluorPen 1.0 software (optional)
• Bluetooth, USB or serial communication (optional)
• GPS mapping plug-in (optional)
• Export to Microsoft Excel (optional)

Specifications:

• Measured Parameters: NDGI = (R780-R525)/(R780+R525) and Nitrogen content in % calibrated for particular plant (wheat, barley and corn) or relative content for other species
• Measuring Light: Dual wavelength light source (525 nm, 780 nm)
• Detector Wavelength Range: 500 to 800 nm bandpass filters
• Memory Capacity: Up to 4 Mb
• Internal Data Logging: Up to 100,000 data points
• Display: 2 x 8 characters LCD
• Keypad: Sealed, 2-key tactile response
• Keypad Escape Time: Turns off after 3 minutes of no use
• Power Supply: 4 AAA alkaline or rechargeable batteries
• Battery Life: 48 hours typical with full operation
• Low Battery Detection: Low battery indication displayed
• Size: 120 x 57 x 30 mm (4.7 x 2.2 x 1.2″)
• Weight: 180 g (6.5 oz)
• Operating Conditions:  Temperature: 0 to 55ºC (32 to 130ºF), Relative Humidity: 0 to 95 % (non-condensing)
• Storage Conditions:   Temperature: -10 to 60ºC (14 to 140ºF). Relative Humidity: 0 to 95% (non-condensing)
• Warranty: 1 year parts and labor

References:

• Klem K. (2008): Prediction of spring barley nutrition state and grain quality using spectral reflectance and chlorophyll fluorescence. Precision Agriculture – ICPA 2008.

The Z951 NDVI-Pen is a hand-held battery-powered PlantPen that helps to characterize plants by means of reflectance. The Normalized Difference Vegetation Index (NDVI), an important indicator of chlorophyll content in plants, is calculated from measurements of reflected light at two distinct wavelengths, Red (635nm) and NIR (760 nm).

the Z951 NDVI-Pen is rugged and compact . It can be used in the field, in the plant biology lab or in teaching plant biology . A handy leaf clip, simple two-button operation, and a bright display make this PlantPen an easy-to-use instrument that does not disturb investigated plants (no leaf tearing or damaging).

It takes four AAA alkaline batteries and is supplied in a robust case. The memory of NDVI-Pen has a capacity of 4 MB (up to 100,000 data points). Measured data are numbered and may be recalled in sequence for later transcription to a computer. More sophisticated models incorporate Bluetooth technology, USB dongle or a Serial Port for data transfer to a PDA or PC.  In addition to NDVI-Pen we also offer the Z950 PRI-Pen, which measures the Photochemical Reflectance Index (PRI).

We also offer non-standard PlantPens that can measure other structural or chlorophyll indices. The customer can choose, for instance, from the Greenness Index, Modified Chlorophyll Absorption in Reflectance Index, Triangular Vegetation Index, Simple Ratio Index, Optimized Soil-Adjusted Vegetation Index, and many others. For more information and custom pricing contact Qubit Systems at Contact Qubit.

Applications:

• Photosynthesis research and education
• Plant biology
• Plant screening & field studies
• Stress physiology
• Agronomy & forestry

Software:

• FluorPen 1.0 software (Windows 2000, XP, or higher compatible)
• Bluetooth, USB or serial communication
• Visualization and data transfer routines to Microsoft Excel
• GPS mapping plug-in

Specifications:

• Measured Parameters: NDVI (Normalized Difference Vegetative Index) = (R760 – R635) / (R760 + R635)
• Measuring Light: Internal dual wavelength light source VIS = 635nm, NIR = 760nm
• Detector Wavelength Range: PIN photodiode with 630 to 800 nm bandpass filters
• FluorPen Software: Windows 2000, XP, or higher
• Sample Holder:  Mechanical leaf clip
• Bios: Upgradeable firmware
• Communication: Bluetooth 1.1, USB dongle or seial port (optional)
• Memory Capacity: Up to 4Mb
• Internal Data Logging: Up to 100,000 data points
• Display: 2 x 8 characters LC display
• Keypad: Sealed, 2-key tactile response
• Keypad Escape Time: Turns off after 5 minutes of no use
• Power Save Mode: Autosleep
• Power Supply: 4 AAA alkaline or rechargeable batteries
• Battery Life: 70 hours typical with full operation
• Low Battery Detection: Low battery indication displayed
• Size: 57 x 30 x 120 mm
• Weight: 180 g
• Operating Conditions: Temperature: 0 to +55ºC; 32 to +130ºF Relative humidity: 0 to 95% (non-condensing)
• Storage Conditions: Temperature: -10 to +60ºC; 14 to +140ºF Relative humidity: 0 to 95% (non-condensing)
• Warranty: 1 year parts and labor

Structural Indices:

• Normalized Difference Vegetation Index (NDVI) Reference: Rouse et al. (1974) Equation: NDVI = (R_NIR – R_RED ) / (R_NIR + R_RED )
• Simple Ratio Index (SR) Reference: Jordan (1969); Rouse et al. (1974) Equation: SR = R_NIR / R_RED
• Modified Chlorophyll Absorption in Reflectance Index (MCARI1) Reference: Haboudane et al. (2004) Equation: MCARI1 = 1.2 * [2.5 * (R800- R670) - 1.3 * (R800- R550)]
• Optimized Soil-Adjusted Vegetation Index (OSAVI) Reference: Rondeaux et al. (1996) ) Equation: OSAVI = (1 + 0.16) * (R₈₀₀- R₆₇₀) / (R₈₀₀- R₆₇₀ + 0.16)

Chlorophyll Indices:

• Greenness Index (G) Equation: G = R₅₅₄ / R₆₇₇
• Modified Chlorophyll Absorption in Reflectance Index (MCARI) Reference: Daughtry et al. (2000) Equation: MCARI = [(R₇₀₀- R₆₇₀) - 0.2 * (R₇₀₀- R₅₅₀)] * (R₇₀₀/ R₆₇₀)
• Transformed CAR Index (TCARI) Reference: Haboudane et al. (2002) Equation: TSARI = 3 * [(R₇₀₀- R₆₇₀) - 0.2 * (R₇₀₀- R₅₅₀) * (R₇₀₀/ R₆₇₀)]
• Triangular Vegetation Index (TVI) Reference:Broge and Leblanc (2000) Equation: TVI = 0.5 * [120 * (R₇₅₀- R₅₅₀) - 200 * (R₆₇₀- R₅₅₀)]
• Zarco-Tejada & Miller Index (ZMI) Reference: Zarco-Tejada et al. (2001) Equation: ZMI = R₇₅₀ / R₇₁₀
• Simple Ratio Pigment Index (SRPI) Reference: Peñuelas et al. (1995) Equation: SRPI = R₄₃₀ / R₆₈₀
• Normalized Phaeophytinization Index (NPQI) Reference: Barnes et al. (1992) Equation: NPQI = (R₄₁₅- R₄₃₅) / (R₄₁₅+ R₄₃₅)
• Photochemical Reflectance Index (PRI) Reference: Gamon et al. (1992) Equation: PRI = (R₅₃₁- R₅₇₀) / (R₅₃₁+ R₅₇₀)
• Normalized Pigment Chlorophyll Index (NPCI) Reference: Peñuelas et al. (1994) Equation: NPCI = (R₆₈₀- R₄₃₀) / (R₆₈₀+ R₄₃0)
• Carter Indices Reference: Carter (1994), Carter et al. (1996) Equation: Ctr1 = R₆₉₅ / R₄₂₀; Ctr2 = R₆₉₅ / R₇₆₀
• Lichtenthaler Indices Reference: Lichtenthaler et al. (1996) Equation: Lic1 = (R₈₀₀ – R₆₈₀) / (R₈₀₀ + R₆₈₀); Lic2 = R₄₄₀ / R₆₉₀
• Structure Intensive Pigment Index (SIPI) Reference: Peñuelas et al. (1995) Equation: SIPI = (R₈₀₀- R₄₅₀) / (R₈₀₀+ R₆₅₀)
• Gitelson and Merzlyak Indices Reference: Gitelson & Merzlyak (1997) Equation: GM1 = R₇₅₀/ R₅₅₀; GM2 = R₇₅₀/ R₇₀₀)

The Z950 PRI-Pen is a hand-held, battery-powered PlantPen that helps to characterize plants by means of reflectance. It measures Photochemical Reflectance Index (PRI) by comparing leaf reflectance in two narrow wavelength bands centered close to 531 nm and 570 nm. PRI is sensitive to changes in carotenoid pigments that are indicative of changes in photosynthetic light use efficiency, the rate of CO2 uptake and as a reliable water-stress index.

Z950 PRI-Pen is rugged and compact .  It can be used in the field, in the plant biology lab or in teaching  plant biology.  A handy leaf clip, simple two-button operation, and a bright display make this PlantPen an easy-to-use instrument that does not disturb investigated plants (no leaf tearing or damaging).

It takes four AAA alkaline batteries and is supplied in a robust case. The memory of PRI-Pen has a capacity of 4 MB (up to 100,000 data points). Measured data are numbered and may be recalled in sequence for later transcription to a computer. More sophisticated models incorporate Bluetooth technology, USB dongle or a Serial Port for data transfer to a PDA or PC.

In addition to PRI-Pen we  offer the Z951 NDVI-Pen, which measures the Normalized Difference Vegetation Index (NDVI).

We also offer non-standard PlantPens that can measure other structural or chlorophyll indices. The customer can choose, for instance, from the Greenness Index, Modified Chlorophyll Absorption in Reflectance Index, Triangular Vegetation Index, Simple Ratio Index, Optimized Soil-Adjusted Vegetation Index, and many others. For more information and custom pricing  Contact Qubit.

Applications:

• Photosynthesis research and education
• Plant biology
• Plant screening & field studies
• Stress physiology
• Agronomy & forestry

Software:

• FluorPen 1.0 software (Windows 2000, XP, or higher compatible)
• Bluetooth, USB or serial communication (optional)
• Visualization and data transfer routines to Microsoft Excel (optional)
• GPS mapping plug-in (optional)

Specifications:

• Measured Parameter: PRI (Photochemical Reflectance Index)
  PRI = (R531 – R570) / (R531 + R570)
• Measuring Light: Internal dual wavelength light source R531 = 531 nm, R570 = 570 nm
• Detector Wavelength Range:PIN photodiode with 500 to 600 nm bandpass filters
• FluorPen 1.0 Software: Windows 2000, XP, or higher
• Sample Holder: Mechanical leaf clip
• Bios: Upgradeable firmware
• Communication: Bluetooth 1.1, USB dongle or serial port
• Memory Capacity: Up to 4Mb
• Internal Data Logging: Up to 100,000 data points
• Display: 2 x 8 characters LC display
• Keypad: Sealed, 2-key tactile response
• Keypad Escape Time: Turns off after 5 minutes of no use
• Power Save Mode: Autosleep
• Power Supply: 4 AAA alkaline or rechargeable batteries
• Battery Life: 70 hours typical with full operation
• Low Battery Detection: Low battery indication displayed
• Size: 57x30x120 mm
• Weight: 180 g
• Operating Conditions: Temperature: 0 to +55ºC; 32 to +130ºF Relative humidity: 0 to 95% (non-condensing)
• Storage Conditions: Temperature: -10 to +60ºC; 14 to +140ºF Relative humidity: 0 to 95% (non-condensing)
• Warranty: 1 year parts and labor

Structural Indices:

• Normalized Difference Vegetation Index (NDVI) Reference: Rouse et al. (1974) Equation: NDVI = (R_NIR – R_RED ) / (R_NIR + R_RED )
• Simple Ratio Index (SR) Reference: Jordan (1969); Rouse et al. (1974) Equation: SR = R_NIR / R_RED
• Modified Chlorophyll Absorption in Reflectance Index (MCARI1) Reference: Haboudane et al. (2004) Equation: MCARI1 = 1.2 * [2.5 * (R₈₀₀- R₆₇₀) - 1.3 * (R₈₀₀- R₅₅₀)]
• Optimized Soil-Adjusted Vegetation Index (OSAVI) Reference: Rondeaux et al. (1996) ) Equation: OSAVI = (1 + 0.16) * (R₈₀₀- R₆₇₀) / (R₈₀₀- R₆₇₀ + 0.16)

Chlorophyll Indices:

• Greenness Index (G) Equation: G = R₅₅₄ / R₆₇₇
• Modified Chlorophyll Absorption in Reflectance Index (MCARI) Reference: Daughtry et al. (2000) Equation: MCARI = [(R₇₀₀- R₆₇₀) - 0.2 * (R₇₀₀- R₅₅₀)] * (R₇₀₀/ R₆₇₀)
• Transformed CAR Index (TCARI) Reference: Haboudane et al. (2002) Equation: TSARI = 3 * [(R₇₀₀- R₆₇₀) - 0.2 * (R₇₀₀- R₅₅₀) * (R₇₀₀/ R₆₇₀)]
• Triangular Vegetation Index (TVI) Reference:Broge and Leblanc (2000) Equation: TVI = 0.5 * [120 * (R₇₅₀- R₅₅₀) - 200 * (R670- R₅₅₀)]
• Zarco-Tejada & Miller Index (ZMI) Reference: Zarco-Tejada et al. (2001) Equation: ZMI = R₇₅₀ / R₇₁₀
• Simple Ratio Pigment Index (SRPI) Reference: Peñuelas et al. (1995) Equation: SRPI = R₄₃₀ / R₆₈₀
• Normalized Phaeophytinization Index (NPQI) Reference: Barnes et al. (1992) Equation: NPQI = (R₄₁₅- R₄₃₅) / (R₄₁₅+ R₄₃₅)
• Photochemical Reflectance Index (PRI) Reference: Gamon et al. (1992) Equation: PRI = (R₅₃₁- R₅₇₀) / (R₅₃₁+ R₅₇₀) Normalized Pigment Chlorophyll Index (NPCI) Reference: Peñuelas et al. (1994) Equation: NPCI = (R₆₈₀- R₄₃₀) / (R₆₈₀+ R₄₃₀)
• Carter Indices Reference: Carter (1994), Carter et al. (1996) Equation: Ctr1 = R₆₉₅ / R₄₂₀; Ctr2 = R₆₉₅ / R₇₆₀
• Lichtenthaler Indices Reference: Lichtenthaler et al. (1996) Equation: Lic1 = (R₈₀₀ – R₆₈₀) / (R₈₀₀ + R₆₈₀); Lic2 = R₄₄₀ / R₆₉₀
• Structure Intensive Pigment Index (SIPI) Reference: Peñuelas et al. (1995) Equation: SIPI = (R₈₀₀- R₄₅₀) / (R₈₀₀+ R₆₅₀)
• Gitelson and Merzlyak Indices Reference: Gitelson & Merzlyak (1997) Equation: GM1 = R₇₅₀/ R₅₅₀; GM2 = R₇₅₀/ R₇₀₀)

Z990 FluorPen

The basic standard FluorPen model measures two parameters:

• Ft - continuous fluorescence yield in non-actinic light. Ft is equivalent to Fo if the leaf sample is dark-adapted.
• QY - Photosystem II quantum yield. In a dark-adapted leaf this is equivalent to Fv/Fm. In a light-adapted leaf it is equivalent to Fv‘/Fm‘.

More sophisticated FluorPen models can measure:

• OJIP – Chlorophyll Fluorescence Induction Kinetics
• NPQ – Non-Photochemical Quenching
• Light Curve – Adaptation of Quantum Yield to Several Different Light Levels

Ft and QY data are stored in the FluorPen memory after they are measured. Each value is numbered sequentially and may be recalled for transcription to a computer. Measuring light power is adjustable by flash duration; actinic and saturating flashes are adjustable from 0 to 3,000 µmol photons/m2/s.

Herbicide Application:

• Improvement of the effectiveness of herbicide application
• Testing of new herbicides
• High reduction of herbicide use

Photosynthesis Research:

• Field measurement
• Mutant screening
• Stress detection

Agronomy and Forestry:

• Mapping by fluorescence parameters
• Nutrient – Fertilizer analysis

Software (optional):

• FluorPen 2.0 software (Windows 2000, XP, or higher compatible)
• Bluetooth, USB or serial communication
• Real-time and remote control functions
• Export to Microsoft Excel
• GPS mapping plug-in (extra option)

For fully loaded FluorPen, including a PAR meter please see Z995 FluorPen PAR.

FluorPen data capture screen:

Light Curve data capture screen:

NPQ Protocol Includes Five Measurements in Actinic Light and three measurements during dark relaxation.

• NPQ_Ln = (FM – FM_Ln) / FM_Ln
• NPQ_Lss = (FM – FM_Lss) / FM_Lss
• NPQ_Dn = (FM – FM_Dn) / FM_Dn

NPQ data capture screen:

OJIP measurements capture screen:

Explanation of OJIP Parameters:

• Bckg = background
• F0: = F50µs; fluorescence intensity at 50 µs
• FJ: = fluorescence intensity at j-step (at 2 ms)
• Fi: = fluorescence intensity at i-step (at 60 ms)
• FM: = maximal fluorescence intensity
• FV: = FM – F0 (maximal variable fluorescence)
• VJ = (FJ – F0) / (FM – F0)
• Vi = (Fi – F0) / (FM – F0)
• FM / F0
• FV / F0
• FV/ FM
• M0 or (dV / dt)0 = TR0 / RC – ET0 / RC = 4 (F300 – F0) / (FM – F0)
• Area = area between fluorescence curve and FM (background subtracted)
• Fix Area = total area above the OJIP fluorescence transient – between F40µ and F1s(background subtracted)
• SM = area / FM – F0 (multiple turn-over)
• Ss = the smallest Sm turn-over (single turn-over)
• N = SM . M0 . (1 / VJ) turn-over number QA
• Phi_P0 = 1 – (F0 / FM (or FV / FM)
• Psi_0 = 1 – VJ
• Phi_E0 = (1 – F0 / FM)) . Psi_0
• Phi_D0 = 1 – Phi_P0 – (F0 / FM)
• Phi_Pav = Phi_P0 – (SM / tFM); tFM) = Time to reach FM (in ms)
• ABS / RC = M0 . (1 / VJ) . (1 / Phi_P0)
• TR0 / RC = M0 . (1 / VJ)
• ET0 / RC = M0 . (1 / VJ) . Phi_0)
• DI0 / RC = (ABS / RC) – (TR0 / RC)

Formulas Derived From:

R.J. Strasser, A. Srivastava and M. Tsimilli-Michael (2000): The fluorescence transient as a tool to characterize and screen photosynthetic samples. In: Probing Photosynthesis: Mechanism, Regulation and Adaptation (M. Yunus, U. Pathre and P. Mohanty, eds.), Taylor and Francis, UK, Chapter 25, pp 445-483.

Specifications:

• Measured Parameters: Fo, Ft, Fm, Fm’ (standard), Kautsky induction (OJIP), Fast kinetics (optional)
• Actinic and Saturating Light: Adjustable from 0-3000 uE
• Measuring Light: Adjustable by duration
• Detector Wavelength: Range PIN photodiode with 697nm – 750nm bandpass filters
• FluorPen Software: Windows 2000, XP, or higher
• Sample Holder: Mechanical leaf clip
• Bios Upgradeable firmware
• Communication:  Bluetooth 1.1 or USB/serial port (optional)
• Memory Capacity: Up to 4Mb
• Internal Data: Logging Up to 100,000 data points
• Display: 2 x 8 characters LC display
• Keypad: Sealed, 2-key tactile response
• Keypad Escape Time: Turns off after 5 minutes of no use
• Power Save Mode: Autosleep
• Power Supply: 4 AAA alkaline or rechargeable batteries
• Battery Lif:e 70 hours typical with full operation
• Low Battery Detection: Low battery indication displayed
• Size: 57 x 30 x 120 mm
• Weight: 180 g
• Operating Conditions: Temperature: 0 to +55ºC; 32 to +130ºF Relative humidity: 0 to 95% (non-condensing)
• Storage Conditions: Temperature: -10 to +60ºC; 14 to +140ºF Relative humidity: 0 to 95% (non-condensing)
• Warranty: 1 year parts and labor

References:

• Fernandez-Marin B. Becerril JM, Garcia-Plazaola JI.  Unravelling the roles of desiccation-induced xanthophyll cycle activity in darkness: a case study in Lobaria pulmonary: Planta 231:1335–1342 (2010)
• Ruiz-Sanchez. M. et al. The arbuscular mycorrhizal symbiosis enhances the photosynthetic efficiency and the antioxidative response of rice plants subjected to drought stress: Journal of Plant Physiology 167(11):862-869 (2010)
• Frolec J,  Rebıcek J, Lazar D, Naus J, Impact of two different types of heat stress on chloroplast movement and fluorescence signal of tobacco leaves.  Plant Cell Rep 29:705–714 (2010)
• Harding SA et al. A comparative analysis of phenylpropanoid metabolism, N utilization, and carbon partitioning in fast- and slow-growing Populus hybrid clones.  Journal of Experimental Botany 60: 3443-3452 (2009)
• Zhang M. et al. : Ecology and Environmemtal Sciences 18 (6): 2272-2277 (2009).
• Kuvykin I.V. et al. Computer simulation study of pH-dependent regulation of electron transport in chloroplasts: Cell Biophysics 54(4):455-464 (2009)
• Chitu E, Ionita AD, Cirjaliu-Murgea M, Chitu V, Filipescu L.  Evaluation of Foliar Nutritive Fluids Effect on Apple Photosystem II Efficiency using Chlorophyll Fluorescence Bulletin UASVM Horticulture, 66(1)/(2009) Print ISSN 1843-5254; Electronic ISSN 1843-5394
• Macek P, Mackova J, de Bello F. Morphological and ecophysiological traits shaping altitudinal distribution of three Polylepis treeline species in the dry tropical Andes. Acta Oecologica 35 778–785 (2009) 
• Rosescu MR,Andrei M. The study of photosystem II efficiency on selected synanthropic plant species.  Annals, Food Science and technology V10, pg 115-119 (2009)
• Woo N.S. Badger MR, Pogson BJ.  A rapid, non-invasive procedure for quantitative assessment of drought survival using chlorophyll fluorescence: Plant Methods 4(27) (2008)