The OS5p+ is designed to be the most advanced chlorophyll fluorometer available. It is intended for advanced plant research and plant stress measurement. It offers the latest updates in chlorophyll fluorescence capabilities, including: FM' correction according to Loriaux 2013, a stable white actinic white light source that allows chloroplast migration, and quenching relaxation measurement of qE, qT, qM, qZ, and qI. It also provides a comprehensive list of quenching protocols including Kramer lake model, Hendrickson lake model, and puddle model protocols. Other capabilities include: A Y(II) protocol, an FV/FM protocol, Strasser OJIP, Vredenberg OJIP, and Rapid Light Curves (for changing light conditions).

Parameters Measured and Protocols included:

Y(II):

Quantum Photosynthetic Yield of PSII (or F/FM' or Y).

ETR:

Electron transport rate (w/optional clip).

PAR:

Photosynthetically Active Region value (with optional PAR clip).

T:

Leaf temperature (with optional PAR clip).

FV/FM:

Maximum Photochemical efficiency of PSII.

FV/FO:

A more sensitive detector of stress than FV/FM, but it does not measure plant efficiency.

FO:

Minimum fluorescence.

FM:

Maximal fluorescence.

FV:

Variable fluorescence.

FMS (or FM'):

Maximal fluorescence with actinic illumination at steady state fluorescence.

FS (or F):

Fluorescence under steady state conditions (prior to saturation pulse).

RLC (Rapid light curves):

rETRMAX:

A measure of a leaf's photosynthetic capacity or maximum electron transport rate a is the initial slope of line at low PAR values created by relating ETR to PAR. It provides a measure of quantum efficiency.

Ik=rETRMAX/α:

A measurement of the light intensity where light saturation dominates, or the minimum saturation level.

I:

PAR light intensity at ETRMAX.

Quenching protocol:

Hendrickson lake model quenching protocol:

Y(NPQ), Y(NO), Y(II), NPQ, FV/FM.

Kramer Quenching (standard):

qL, Y(NPQ), Y(NO), Y(II), FV/FM.

Puddle model parameters (standard):

NPQ, qN, qP, Y(II), FV/FM.

Quenching relaxation protocol (standard):

qE, qM, qZ, qT, qI along with either puddle model, or Hendrickson parameters. Adjustable times for each.

OJIP:

Up to 32 traces can be overlaid on the graphic display screen. The data file is designed for easy overlay graphing and spider plot graphing. Thousands of measurement parameter sets can be stored in a single data file for spider graphing. The number of data files are only limited by machine memory limits. FO is measured not estimated.

OJIP - Vredenberg OJIP quenching protocol:

Ft/FO.

OJIP - Strasser Protocol:

Direct readout of: OJIP t100μs, t300μs (or K step), tFM (or time to P or FM), A (or area above the curve), MO (or RC/ABS), PIABS (or performance index).

Strasser OJIP parameters reported to the data file only:

ABS/RC, TRO/RC, DIO/CS, ETO/RC, TRO/ABS, ETO/TRO, ETO/CS,RC/CSO, RC/CSM , S, M, T.

Light Sources:

Saturation pulse:

White LED with 690 nm short pass filter. 15,000 μmols, 7,500 μmols with PAR clip.

Modulated light:

Red: 660 nm LED with 690 nm short pass filter.

Actinic light source:

RGB light source with adjustable spectra. Intensity adjustable up to 6,000 μmols.

Far red light:

720 nm LED with >700nm long pass filter.

Detection method:

Pulse modulation method.

Detector & Filters:

A PIN photodiode with a 700 ~ 750 nm bandpass filter.

Sampling Rate:

Auto-switching from 1 to 10,000 points per second, depending on test & on phase of test.

Automated routine to optimally set the modulated light intensity. The modulated light may also be set manually.

Multi-Flash FM' correction for all light adapted protocols & quenching. It may be turned on or off.

Operational:

Test Duration:

Adjustable from .1 seconds to 12 hours.

GPS location:

Built in GPS / GLONASS 12 channel receiver with internal antenna.

Storage Capacity:

1 Gigabyte of non-volitile flash memory.

Digital Output:

USB removable storage device standard. Comma delimited files.

SD/MMC data card.

User Interface:

640 x 480 graphic color touch screen.

Menu driven touch screen.

Power Supply:

Internal 12V rechargeable nickel metal hydride battery.

Battery Life:

6 to 8 hours of continuous operation.

Dimensions:

7 in x 5.5 in x 3.25 in (17.8 cm x 14 cm x 8.3 cm).

Weight:

3.6 lbs (1.6 kg).

Operating temperature:

0 - 50oC, non condensing.

Specifications subject to change without notice.

PDF document.