In many industries, it is desirable to be able to continually test and measure the density of a liquid being processed to determine what stage the liquid is at. A hydrometer is often used to measure the specific gravity or relative density of the liquid being processed. To use such a hydrometer, a sample of liquid may be drawn into a testing cup. The hydrometer may then be placed into the cup and the level at which the hydrometer floats within the sample is recorded from a graduated scale on the hydrometer. The raw reading of this sort of measuring device can be affected by temperature. If the liquid being tested is warmer, the liquid may be less viscous, even if it has the same amount of material suspended in the same volume of water. So, at different temperatures, the hydrometer reading for the same density may differ. These differences in reading based on temperature are usually compensated for by reference to a table showing, for a given density, a list of values that should be read at different temperatures.
By way of a non-limiting example, in the maple syrup industry, it desirable to test the sugar content of the sap as it is being processed to determine progress. As the sugar concentration increases (as the sap is reduced), the temperature of boiling or vaporization increases. Thus, as the sap being processed gets closer to the desired concentration of sugar, the value to be read from the hydrometer differs from when the sap is first introduced into the process. Conventional approaches to determining the density (and sugar concentration) of the sap being processed into syrup recommend sampling the liquid at as close to the same temperature as possible each time. Standard hydrometers used in the industry are calibrated for use at a set temperature, typically either reading in the BRIX scale and/or the Baume scale. When readings are taken at a different temperature from the set temperature, the user consults a table to determine the reading that should be read from the hydrometer to achieve the BRIX or Baume reading for the desired sugar concentration. This conventional process is shown in FIG. 6.
Other industries, such as but not limited to the brewing and the distilling industries, also use hydrometers to measure density or concentrations at different points in the brewing and/or distilling process. These industries also deal with temperature ranges that can affect the readings taken directly from the hydrometer and which are corrected to a proper baseline through the use of conversion tables.
Improvements to these conventional approaches to measuring the density or specific gravity of a liquid to determine concentration of elements within the liquid are desirable.
USPTO Backgrounds
USPTO Backgrounds