| abstract |
A method and apparatus for measuring properties of a liquid compositionnincludes a mechanical resonator, such as a thickness shear mode resonatornor a tuning fork resonator, connected to measurement circuit. The measurementncircuit provides a variable frequency input signal to the tuning fork,ncausing the mechanical resonator to oscillate. To test the propertiesnof a liquid composition, the mechanical resonator is placed inside a samplenwell containing a small amount of the liquid. The input signal is then sentnto the mechanical resonator and swept over a selected frequency range,npreferably less than 1 MHz to prevent the liquid being tested fromnexhibiting gel-like characteristics and causing false readings. n The mechanical resonator's response over the frequency range depends onnvarious characteristics of the liquid being tested, such as the temperature,nviscosity, and other physical properties. |