MultispeQ Protocols

A collection of curated protocols for the MultispeQ.

Photosynthetically Active Radiation (PAR)

Use the MultispeQ’s PAR sensor to measure light intensity (400-700nm) in µmol photons × s⁻¹ × m⁻², which represents the Photosynthetically Active Radiation.

This protocol outputs the PAR value, as well as the raw values for the red, green, and blue channel of the sensor.

Photosystem II efficiency (ϕₗₗ)

Basic protocol to measure the Photosystem II efficiency called phi2 or \(\Phi_{II}\). From the fluorescence trace several more values are produced, including \(F_{S}\), the steady state fluorescence, \(F_{M}\), the maximum fluorescence, and LEF, the linear electron flow, based on phi2 and the ambient light intensity.

Photosynthesis (RIDES)

Measures the same photosynthesis-related parameters in <15 seconds as ‘Leaf Photosynthesis MutlispeQ v2.0’ plus additional PS1 and P700 measurements.

  • Chlorophll Fluorescence: Phi2, PhiNPQ, PhiNO, NPQt, qL, LEF

  • Relative Chlorophyll

  • ATP synthase conductivity, proton motive force parameters through DIRK(ECS): ECSt mAU, vH+, gH+

  • Saturation pulse estimation of PSI parameters: PS1 active centers, PS1 open, PS1 oxidized and PS1 over reduced

  • Absorbance at: 450, 535, 605, 650, 730, 850, 880, and 940nm.

  • The rate of turnover of the cytochrome b6f complex through DIRKP(700)

  • Leaf Thickness (in mm), angle, and cardinal direction

  • Leaf Temperature and differential from ambient temperature

  • Environmental conditions: PAR and ambient temperature/pressure/humidity

Important

Supports MultispeQ V1 and V2 with Firmware 2.34 and higher

Relative Chlorophyll Content (SPAD)

This protocol measures basic absorbance at 650 nm and 940 nm and calculates the relative chlorophyll content.

The value returned represents the Special Products Analysis Division (SPAD) to make it comparable to other instruments used in the field.

\(SPAD = k \times \log_{10}\frac{Abs_{940nm} / ref. Abs_{940}}{Abs_{650nm} / ref. Abs_{650}}\)

\(k\) is a proprietary correlation coefficient used in the Minolta’s calculation of SPAD.

Note

Only works with MultispeQ v2.0

Calibrations

A collection of curated protocols for the MultispeQ calibration.

Electronic Offsets Calibration

new electronic offsets calibration

2230

Fluorescence - Detector Offsets

allows for correction of small offsets in the measurements caused by actinic light current/ground loop on main and addon boards

Used with Bleed CAL#7B

These calibration steps require the chlorophyll calibration and the pink fluorescent cards

2231

IR LED Calibration

used to adjust the output of non PAR LEDS

Warning

These calibration steps require a CaliQ

2229

Leaf Clamp LEDs Calibration

new version of CaliQ LED output calibration using PAR matching…

qpar matching 1 testing CaliQ step 4 Calibrate LOWER PAR LEDs

Warning

This calibration requires a CaliQ

2279

Leaf Thickness Gauge Calibration

Description

The MultispeQ measures leaf thickness by using a Hall Effect sensor located on the main body of the MultispeQ and a magnet located on the clamp body. The Hall Effect sensor measures the density of magnetic field lines, and as the clamp opens and the magnet moves farther away, the field lines go farther apart. This extremely precise sensor is able to detect differences of 10s of microns given a consistent setup. Precision in the field is not that good, as dirt, bumps and veins in the leaf, and other noise can interfere.

Calibration of the Hall Effect sensor requires the measurement of objects of a few known thicknesses, and a calibration curve (2nd order polynomial fit) of the resulting Hall Effect detector response to the actual values.

In addition, the Hall Effect sensor is also used to identify fully closed and fully open positions, which is used to automatically start a measurement on clamp (the “open_close_start” command). This is used in the “Leaf Photosynthesis” protocol, for example. If you want to only recalibrate the fully open and fully closed positions, then run the “v1.0 CALIBRATION: Leaf Thickness Quick” calibration instead.

Directions

Run this protocol using the Desktop App (it is the only app which can currently display messages) Make sure you have 6 plastic strips of known thickness (from .05 to 3mm). Run the protocol, following the directions provided by the messages. Once complete, press the “save to device” button to save the outputs to the MultispeQ device. If it is running as part of a Calibration Project (as during factory calibration), then press “keep” to save the values to the photosynq.org 1website. As with any values saved to the MultispeQ, you can see the saved calibration values by opening the Desktop App, going to “Settings” –> “console”, and entering print_memory+ . The leaf thickness values are saved as “thickness_a”,”thickness_b”,”thickness_c”,”thickness_min”,”thickness_max”.

2232

Main Body LEDs Calibration

new version of CaliQ LED output calibration using PAR matching…

Warning

This calibration requires a CaliQ

2280

PAR Sensor Calibration

adjusts the MultispeQ PAR sensor values (without changing the color balance) using a known “universal” PAR level and darkness.

When using the CaliQ for calibrating the PAR sensor, make sure it is connected and communicating before starting the calibration procedure. To check if it is properly connected, go to Instrument Settings and test the connection.

Warning

This calibration requires a CaliQ device

ID: 2225

Relative Chlorophyll (SPAD) Calibration

Follow the instructions prompted by the protocol. Make sure the panels of the calibration cards are properly clamped.

Warning

This calibration method requires a set of calibration cards

ID: 1890

Reset to Default Settings

Reset the MultispeQ to its default settings and remove all calibrations

2221