Temperature correction

Certain applications may require a correction to account for the thermal expansion of the hydrometer glass, if the measuring temperature deviates from the reference temperature of the hydrometer. This factor corrects the result for the corresponding measuring temperature.

    K_t = (1-γ (t - t₀ )) ρ

Conversion tables for measured densities to different temperature can be found in many chemical references. These tables can provide expansion coefficients and densities for different sample temperatures and concentrations.

K_t   For the density after correction

γ   Volume expansion coefficient of the hydrometer glass
     (25 ± 2) 10^-6 K^-1

t   Measuring temperature (°C)

t₀  Reference temperature (°C)

ρ  Density reading (g/ml)