# User defined output unit set For all the flash computations, the user can optionally specify the unit of each output value in the [Stream output](https://devdocs.olisystems.com/stream-output-json) in the **params.unitSetInfo** section. The table below describes the supported output units. | params.unitSetInfo | definition | default unit | units available | | -------------------- | --------------------------------- | --------------------- | -------------------------------------------------------------------------------- | | liq1\_phs\_comp | liquid 1 phase composition | mol | see composition units below | | solid\_phs\_comp | solid phase composition output | mol | see composition units below | | vapor\_phs\_comp | vapor phase composition output | mol | see composition units below | | liq2\_phs\_comp | liquid 2 phase composition output | mol | see composition units below | | combined\_phs\_comp | total composition output | mol | see composition units below | | density | density of a phase/total stream | g/L | g/ml, kg/m3, g/L, kg/L, lb/ft3, lb/gal | | mass | mass of a phase/total stream | g | g, kg, lb, mg, (g/100), metric ton | | vol | volume of a phase/total stream | L | L, ml, cm3, m3, E3m3, E6m3, ft3, Mft3, MMft3, gal, MMgal, bbl | | moles | total moles in a phase/stream | mol | mol, kgmol, lbmol, mmol, μmol, (mol/100) | | pt | pressure of stream | atm | atm, bar, barg, mbar, Pa, kPa, MPa, mmHg, Torr, inHg, psia, psig, inH2O, kg/cm2 | | t | temperature of stream | °C | K, degree\_Fahrenheit, °C, °F, degree\_Celsius, R | | enthalpy | enthalpy of a phase/stream | cal | cal, E3cal, E6cal, J, kJ, MJ, Btu, MMBtu | | visabs | Absolute viscosity | cP | cP, Poise, Pa-s | | i | Ionic strength, x-based | mol/mol | mol/mol | | im | Ionic strength, m-based | mol/kg | mol/kg | | econd | Specific electric conductivity | µmho/cm | mho/m, mho/cm, µmho/m, µmho/cm | | econdm | Molar electric conductivity | m2/ohm-mol | m2/ohm-mol, cm2/ohm-mol | | fug | Fugacity | atm | atm, bar, barg, mbar, Pa, kPa, MPa, mmHg, Torr, inHg, psia, psig, inH2O, kg/cm2 | | mob | Mobilities | cm2/s-volt | cm2/s-volt, m2/s-volt | | dif | Self diffusivity | m2/s | m2/s | | alkalinity | Alkalinity | mg HCO3/L | eq/L, meq/L, mg HCO3/L, mg CO3/L, mol HCO3/L, mol CO3/L, mg CaCO3/L, mol CaCO3/L | | tds | Total dissolved solids | mg/L | mg/L | | cp | Heat capacity | cal/g K | J/kg K, J/g K, cal/g K, Btu/lb R | | entr | Entropy | cal/K | J/K, cal/K, Btu/R | | thermalcond | Thermal conductivity | cal/hr m °C | Btu/hr ft °F, cal/hr m °C, cal/s m °C, J/s m K | | surface\_tension | Surface tension | N/m | N/m, dyne/cm | | mol\_entr | Molar entropy | cal/mol K | J/mol K, cal/mol K, Btu/mol R | | interfacial\_tension | Interfacial tension | N/m | N/m, dyne/cm | | kinetics\_k | K value of kinetic reaction | mol/hr m3 | mol/hr m3 | | kinetics\_rate | Kinetic reaction rate | mol/hr hr | mol/hr hr | | kinetics\_extent | Kinetic reaction extent | mol/hr | mol/hr | | hardness | Hardness | mg/L of Mg+2 and Ca+2 | mg/L of Mg+2 and Ca+2 | | tic | Total inorganic carbon | mol C/L | mg C/L, g C/L, mol C/L | | energy | Gibbs free energy | cal | cal, E3cal, E6cal, J, kJ, MJ, Btu, MMBtu | | mol\_energy | Molar Gibbs free energy | cal/mol | cal/mol, E3cal/mol, E6cal/mol, J/mol, kJ/mol, MJ/mol, Btu/mol, MMBtu/mol | | part\_pressure | Partial pressure | atm | atm, bar, barg, mbar, Pa, kPa, MPa, mmHg, Torr, inHg, psia, psig, inH2O, kg/cm2 | | molefrac | Mole fraction | mol/mol | mol/mol, mole %, ppm (mole) | | induction\_time | scaling induction time | hr | s, min, hr, day, yr | {% hint style="success" %} All unit entries do not have to be specified. The ones that are not will be overridden by the default. {% endhint %} #### Composition units | unit types | units | | ------------- | ------------------------------------------ | | moles | `mol, kgmol, lbmol, mmol, µmol, (mol/100)` | | mole fraction | `mol/mol, mole %, ppm (mole)` | | mass | `g, kg, lb, mg, (g/100), metric ton` | | mass fraction | `g/g, mass %, ppm (mass)` | {% hint style="info" %} Composition units can be specified as any units above. {% endhint %} ### JSON input (example) Below is an input sample containing the **params.unitSetInfo** optional object using [isothermal flash](https://devdocs.olisystems.com/group1/api-functions/isothermal) function input as an example. ```javascript { "params": { ...... "unitSetInfo": { "liq1_phs_comp": "mol/mol", "solid_phs_comp": "mol/mol", "vapor_phs_comp": "mol/mol", "liq2_phs_comp": "mol/mol", "combined_phs_comp": "mol/mol", "density": "kg/m3", "mass": "g", "vol": "L", "moles": "mol", "pt": "atm", "t": "°C", "enthalpy": "J", "visabs": "cP", "i": "mol/mol", "im" "mol/kg", "econd": "µmho/cm", "econdm": "m2/ohm-mol", "fug": "atm", "mob": "m2/s-volt", "dif": "m2/s", "alkalinity": "mg HCO3/L", "tds": "mg/L", "current_den": "A/sq-m", "molefrac": "mole %", "cp": "cal/g K", "entr": "cal/K hr", "thermalcond": "cal/hr m °C", "surface_tension": "N/m", "part_pressure": "atm", "mol_entr": "cal/mol K", "interfacial_tension": "N/m", "kinetics_k": "mol/hr m3", "kinetics_rate": "mol/hr hr", "kinetics_extent": "mol", "hardness": "mg/L of Mg+2 and Ca+2", "tic": "mol C/L" } } ``` Explanation of each property and available units will be documented later.