| Basic
SI units |
| metre |
m |
| kilogram |
kg |
| second |
s |
| ampere |
A |
| kelvin |
K |
| candela |
cd |
| mole |
mol |
Remarks:
|
Unit,
dimension
|
Symbol
|
Do
not use
|
| micrometre |
µm |
µ |
| nanometre |
nm |
mµ, Å |
| gram |
g |
gr |
| microgram |
µg |
– |
| second |
s |
sec |
| minute* |
min |
min. |
| hour* |
h |
hr, hrs |
| day |
d |
– |
| year |
a |
– |
| kelvin |
K |
°K |
| degree Celsius (centigrade) |
°C (e.g.
20 °C) |
° C (e.g.
20° C) |
| pasqual |
Pa |
atm, torr, mmHg, bar |
| joule |
J |
cal, kWh |
| watt per metre square |
W m–2 |
cal cm–2
min–1 |
| mole, millimole |
mol, mmol |
– |
| molar, millimolar |
M, mM |
– |
| becquerel |
Bq |
Ci, C, c |
| counts per second |
s–1 |
cpm |
| hertz |
Hz |
c/sec |
| volume per volume |
cm3
m–3 |
vpm |
| mass per mass |
mg kg–1 |
ppm |
The following form of dimensions is preferred:
kg m–2 s–1; if plant as reference unit: µg per plant
Avoid the following usage:
kg . m–2. s–1, kg/m2s, or completely incorrect kg/m2/s
Note that mW is miliwatt
m W is metre × watt
The abbreviation kDa is acceptable for characterising proteins.
*Units h (for hour; not hr, hrs) and min (for minute; not min.) can be used only for description (e.g. centrifuged for 50 min), not as dimensions.
Recommended symbols and most frequently used abbreviations
Most frequent radicals:
Superoxide radical: O2• –
hydroxyl radical: •OH, please, do not mismatch with hydroxyl anion OH–
hydroperoxyl radical: HO2•
| C3(4) – C3 or C4 (plants, mechanisms etc.) |
| Car – carotenoids |
| Chl a(b) – chlorophyll a(b) |
| Ci – intercellular CO2 concentration |
| DM – dry mass |
| E – transpiration rate |
| ETR – electron transport rate |
| F0 – minimal fluorescence of dark-adapted state |
| F0’ – minimal fluorescence of light-adapted state |
| Fm – maximal fluorescence of dark-adapted state |
| Fv – variable fluorescence |
| Fv/Fm – maximal quantum yield of PSII photochemistry |
| FM – fresh mass |
| FRET – fluorescence resonance energy transfer |
| gs – stomatal conductance |
| LA – leaf area |
| LHC – light harvesting complex |
| NPQ – non-photochemical quenching |
| OEC – oxygen-evolving complex |
| PN – net photosynthetic rate |
| PAR – photosynthetically-active radiation |
| PPFD – photosynthetic photon flux density |
| PSI – photosystem I |
| PSII – photosystem II |
| QA – primary quinone acceptor of PSII |
| QB – secondary quinone acceptor of PSII |
| qN – non-photochemical quenching coefficient |
| qP – photochemical quenching coefficient |
| RD – respiration rate |
| RWC – relative water content |
| SD – standard deviation |
| SE – standard error |
| VPD – vapour pressure deficit |
| WUE – water use efficiency |
| ΦPSII – effective quantum yield of PSII photochemistry |
| ψw – water potential |
|
