Hydroponics

Abbreviations and Units

Table 1: Abbreviations and Units
AbbreviationTermDescription
AAreaSquare feet or square meter.
CEAControlled Environment AgricultureProducing plants in a greenhouse or other space.
cmcentimeterA unit of length
CWFCool White FluorescentA type of supplemental lighting
DLIDaily Light IntegralThe sum of photosynthetic (PAR) light received by plants in a day.
DODissolved OxygenOxygen concentration in nutrient solution measured in parts per million.
ECelectrical conductivityAn indirect measurement of the strength of a nutrient solution.
HIDHigh Intensity DischargeA type of HID supplemental lighting
hphorsepowerA unit of power
HPSHigh Pressure SodiumA high intensity discharge lamp/luminaire type for supplemental lighting
kPakilopascalsA unit of pressure, force per unit area
MHMetal HalideA type of HID supplemental lighting
molpronounced 'mole'A number of anything equal to 6.02 x 1023 items. We use it to quantify the number of photons between 400-700 nm of PAR light plants receive.
mol/m²/dmoles per square meter per dayIntegrated PAR light
mol/m²/smoles per square meter per secondInstantaneous PAR light
nmnanometerUnit of length in SI, one billionth of a meter
PARPhotosynthetically Active RadiationThe portion of the electromagnetic spectrum between 400-700 nm plants use for photosynthesis
ppmparts per millionA unit that describes dimensionless quantities such as volume fractions. For describing carbon dioxide concentrations it is a molar basis.
SISystem InternationaleInternational system of units aka metric system - built around 7 basic units of measurements
μmol/m²/smicro-mole per square meter per secondInstantaneous PAR light
μS/cmmicrosiemens per centimeterA unit of measurement for electrical conductivity
Cornell CEA Lettuce Handbook