True Proof calculates the true proof of a water-alcohol mixture at a reference temperature, using the measured apparent proof from a hydrometer reading and the temperature at the time of the reading.
True Proof can also calculate dilutions, taking full account of the nonideal mixing of water and alcohol.
Multiple units support large-scale distillers and hobby-scale distillers alike, in the US and abroad: concentration measurement in proof, Tralle, or density units of g/cm^3 or kg/m^3; temperature in °F or °C; abundance in US gallon, Imperial gallon, liter, pound, kg, US ton, or metric tonne.
The reference temperature can be selected for US (60ºF) or international (20ºC), or any other value in the range [-20ºC,40ºC]. The instrument thermal expansivity can be selected, which enables application to vibrating tube densitometers in addition to hydrometers.