Limits...
Resolution in QCM sensors for the viscosity and density of liquids: application to lead acid batteries.

Cao-Paz AM, Rodríguez-Pardo L, Fariña J, Marcos-Acevedo J - Sensors (Basel) (2012)

Bottom Line: However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC.At the same time, the present theoretical "resolution limit" to measure the square root of the density-viscosity product [Formula: see text] of a liquid medium or best resolution achievable with a QCM oscillator is determined.The QCM resolution limit for [Formula: see text] measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronic Technology, University of Vigo, Campus Lagoas Marcosende, Vigo 36310, Spain. amcaopaz@uvigo.es

ABSTRACT
In battery applications, particularly in automobiles, submarines and remote communications, the state of charge (SoC) is needed in order to manage batteries efficiently. The most widely used physical parameter for this is electrolyte density. However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC. This paper presents a Quartz Crystal Microbalance (QCM) sensor for electrolyte density-viscosity product measurements in lead acid batteries. The sensor is calibrated in H(2)SO(4) solutions in the battery electrolyte range to obtain sensitivity, noise and resolution. Also, real-time tests of charge and discharge are conducted placing the quartz crystal inside the battery. At the same time, the present theoretical "resolution limit" to measure the square root of the density-viscosity product [Formula: see text] of a liquid medium or best resolution achievable with a QCM oscillator is determined. Findings show that the resolution limit only depends on the characteristics of the liquid to be studied and not on frequency. The QCM resolution limit for [Formula: see text] measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

No MeSH data available.


Related in: MedlinePlus

Experimental setup for the calibration of the sensor (a) Connection diagram, (b) Experimental test bench, (c) Quartz Crystal during the calibration with solutions of sulphuric acid.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3472846&req=5

f2-sensors-12-10604: Experimental setup for the calibration of the sensor (a) Connection diagram, (b) Experimental test bench, (c) Quartz Crystal during the calibration with solutions of sulphuric acid.

Mentions: A home-made 9 MHz Miller oscillator was used as SoC QCM sensor for lead acid batteries [6,7]. In order to estimate its experimental sensitivity coefficient to changes in the density-viscosity product of the electrolyte, calibration was performed with the quartz resonator immersed in sulfuric acid solutions thermostated at 30.8 °C using a PolyScience Heating Circulator. The temperature of the electronic oscillator was maintained stable at 42 °C during the calibration using a Watlow heater monitor. The sulfuric acid concentration in the solution was changed in steps from 13% to 40%, which corresponds to a change of 13% to 99% in the state of charge of a battery. To do this, small amounts of concentrated sulfuric acid (95%) were added periodically to the solution in order tosimulate the battery charge process. Figure 2(a,b) shows the equipment used and a connection diagram of the test bench, respectively. A detail of the QCM sensor placement is shown in Figure 2(c). The oscillator frequency and the solution temperature were monitored throughout the whole process with a sampling time of 2 s. Density measurements of the solution were also made for each sulfuric acid concentration step with an Anton Paar DMA-35 precision density meter. Parameters of the equivalent circuit of the resonator were also measured for each concentration with an HP-4194A impedance analyzer.


Resolution in QCM sensors for the viscosity and density of liquids: application to lead acid batteries.

Cao-Paz AM, Rodríguez-Pardo L, Fariña J, Marcos-Acevedo J - Sensors (Basel) (2012)

Experimental setup for the calibration of the sensor (a) Connection diagram, (b) Experimental test bench, (c) Quartz Crystal during the calibration with solutions of sulphuric acid.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472846&req=5

f2-sensors-12-10604: Experimental setup for the calibration of the sensor (a) Connection diagram, (b) Experimental test bench, (c) Quartz Crystal during the calibration with solutions of sulphuric acid.
Mentions: A home-made 9 MHz Miller oscillator was used as SoC QCM sensor for lead acid batteries [6,7]. In order to estimate its experimental sensitivity coefficient to changes in the density-viscosity product of the electrolyte, calibration was performed with the quartz resonator immersed in sulfuric acid solutions thermostated at 30.8 °C using a PolyScience Heating Circulator. The temperature of the electronic oscillator was maintained stable at 42 °C during the calibration using a Watlow heater monitor. The sulfuric acid concentration in the solution was changed in steps from 13% to 40%, which corresponds to a change of 13% to 99% in the state of charge of a battery. To do this, small amounts of concentrated sulfuric acid (95%) were added periodically to the solution in order tosimulate the battery charge process. Figure 2(a,b) shows the equipment used and a connection diagram of the test bench, respectively. A detail of the QCM sensor placement is shown in Figure 2(c). The oscillator frequency and the solution temperature were monitored throughout the whole process with a sampling time of 2 s. Density measurements of the solution were also made for each sulfuric acid concentration step with an Anton Paar DMA-35 precision density meter. Parameters of the equivalent circuit of the resonator were also measured for each concentration with an HP-4194A impedance analyzer.

Bottom Line: However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC.At the same time, the present theoretical "resolution limit" to measure the square root of the density-viscosity product [Formula: see text] of a liquid medium or best resolution achievable with a QCM oscillator is determined.The QCM resolution limit for [Formula: see text] measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronic Technology, University of Vigo, Campus Lagoas Marcosende, Vigo 36310, Spain. amcaopaz@uvigo.es

ABSTRACT
In battery applications, particularly in automobiles, submarines and remote communications, the state of charge (SoC) is needed in order to manage batteries efficiently. The most widely used physical parameter for this is electrolyte density. However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC. This paper presents a Quartz Crystal Microbalance (QCM) sensor for electrolyte density-viscosity product measurements in lead acid batteries. The sensor is calibrated in H(2)SO(4) solutions in the battery electrolyte range to obtain sensitivity, noise and resolution. Also, real-time tests of charge and discharge are conducted placing the quartz crystal inside the battery. At the same time, the present theoretical "resolution limit" to measure the square root of the density-viscosity product [Formula: see text] of a liquid medium or best resolution achievable with a QCM oscillator is determined. Findings show that the resolution limit only depends on the characteristics of the liquid to be studied and not on frequency. The QCM resolution limit for [Formula: see text] measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

No MeSH data available.


Related in: MedlinePlus