Application of quartz tuning forks and extensional microresonators for viscosity and density measurements in oil/fuel mixtures

Electromagnetically driven torsional resonators for viscosity and mass density sensing applications

“…In Fig. 9 the sensitivities obtained with the torsional resonator are depicted in comparison with the sensitivities achieved with circular and rectangular cross sectioned steel tuning forks oscillating at 400 Hz in liquids approximately, a U-shaped wire sensor ( f r ≈ 930 Hz) [27], and a quartz tuning fork ( f r ≈ 32.7 kHz) [13].…”

“…In-plane oscillating devices, oscillating rotational disks [10] and other resonators for viscosity and mass density sensors such as cantilevers [11,12], quartz tuning forks [13] and vibrating bridges [14,15] are based on a similar operational principle. Usually, the devices' frequency responses, containing a characteristic resonant mode, are recorded upon immersion in a sample liquid.…”

Comparison of in-plane and out-of-plane piezoelectric microresonators for real-time monitoring of engine oil contamination with diesel

“…Although typically these do not allow an independent determination of the density and viscosity, higher quality factors in liquid have been reported, associated with lower hydrodynamic loading (Manzaneque et al 2012). In this work we use a relatively thick plate for in-plane vibration, actuated in the first extensional mode in the MHz range (Toledo et al 2014), demonstrating the possibility to separate density and viscosity. The in-plane microresonator used, labelled as "Extensional 130", has a top area of 3000 × 250 µm 2 and 130 µm of thickness.…”

“…This approach presents several advantages with respect to traditional methods of rheological analysis: real-time measurements, on-line configuration, low liquid volumes, etc. The use of microacoustic sensors (Agoston et al 2005) and tuning fork resonators (Milpied et al 2010;Toledo et al 2014) for the monitoring of engine oil condition, has already been reported. In our work we focus on the use of resonant Abstract Real-time monitoring of the physical properties of liquids, such as lubricants, is a very important issue for the automotive industry.…”

Application of resonant steel tuning forks with circular and rectangular cross sections for precise mass density and viscosity measurements

“…The investigated principles featuring fundamental resonance frequencies in the range from some hundreds of hertz to several kilohertz include, amongst others, oscillating membranes [2,3], in-plane oscillating platelets [4,5], straight wires [6] and U-shaped wires [7,8]. Similar miniaturized devices are silicon cantilevers [9,10], quartz crystal tuning forks [11], doubly clamped silicon beams [12] and vibrating diaphragms [13] just to name a few examples of the relatively large variety of principles reported in literature.…”