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EASYDENS – OVERVIEW
The portable density meter EasyDens measures the density of liquids by the oscillating U-tube method. In addition, a
temperature sensor measures the sample temperature directly at the measuring cell.
You operate and control the instrument via the EasyDens app running on your smartphone. For the communication between
EasyDens and your smartphone, Bluetooth is used.
EasyDens features various measuring units for display:
Density [g/cm3or kg/m3]
Specic Gravity SG
Extract [°Plato]
MEASURING PRINCIPLE
Denition of density
The density (ρ) of a sample is dened as its mass (m) divided by its volume (V):
As the volume changes with temperature, density is a temperature-dependent measuring unit.
THE OSCILLATING U-TUBE METHOD
The sample is lled into a U-shaped borosilicate glass tube, which is electronically excited to vibrate at its characteristic
frequency. The characteristic frequency changes depending on the density of the sample. With the determination of the
characteristic frequency, the density of the sample can be calculated. Due to the temperature dependency of the density
value, the temperature of the sample has to be determined precisely.
CONCENTRATION MEASUREMENT
In binary mixtures, the density of the mixture is a function of its composition. Thus, with the aid of density/concentration
tables, the density value of a binary mixture can be used to calculate its composition.
This procedure is also applicable for so-called quasi-binary mixtures. These mixtures contain two major components and
some additional ones in very small concentrations compared to the two main components.
Many decarbonated soft drinks, for example, can be considered to be quasi-binary mixtures of sugar and water because the
concentrations of avors and acids are very small compared to those of sugar and water. Hence the sugar concentration can
be determined with a density meter.
The same holds for the determination of the alcohol concentration in distillates that can be considered to be quasi-binary
mixtures of ethanol and water.
