Correct a hydrometer reading taken at the wrong temperature.
SG_true = SG_read × ρ(T_sample) /ρ(T_calibration)
where ρ is the standard cubic fit of water density in °F. Hot samples read
low (the wort is less dense than the instrument assumes) and the correction
pushes them back up. A 30 °C sample on a 60 °F hydrometer reads about
0.0016 SG low.
Parameters
measuredGravity: number
sampleTempC: number
calibrationTempC: number = DEFAULT_HYDROMETER_CALIBRATION_TEMP_C
Correct a hydrometer reading taken at the wrong temperature.
where ρ is the standard cubic fit of water density in °F. Hot samples read low (the wort is less dense than the instrument assumes) and the correction pushes them back up. A 30 °C sample on a 60 °F hydrometer reads about 0.0016 SG low.