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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

Oscillation frequency and temperature of the QCM sensor during a charge trial.
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f12-sensors-12-10604: Oscillation frequency and temperature of the QCM sensor during a charge trial.

Mentions: With respect to the tests in real-time charge and discharge processes, Figures 12–15 illustrate the results of the trials. Figure 12 shows the oscillation frequency and temperature of the battery during the charge trial. In Figure 13 the values of frequency after temperature compensation with Equations (14)–(17) are shown. After temperature compensation, the oscillation frequency depends only on the variation of viscosity-density product due to the shift of the SoC in accordance with Equation (1). The shift of measured by the QCM sensor is also shown in Figure 13. The sensor presents the expected tendency for the charge process in lead-acid batteries: in the top area of the battery, due to the electrolyte stratification, the density and viscosity do not increase their values significantly until the charge process is advanced and bubbling occurs [2,22].


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)

Oscillation frequency and temperature of the QCM sensor during a charge trial.
© Copyright Policy
Related In: Results  -  Collection

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

f12-sensors-12-10604: Oscillation frequency and temperature of the QCM sensor during a charge trial.
Mentions: With respect to the tests in real-time charge and discharge processes, Figures 12–15 illustrate the results of the trials. Figure 12 shows the oscillation frequency and temperature of the battery during the charge trial. In Figure 13 the values of frequency after temperature compensation with Equations (14)–(17) are shown. After temperature compensation, the oscillation frequency depends only on the variation of viscosity-density product due to the shift of the SoC in accordance with Equation (1). The shift of measured by the QCM sensor is also shown in Figure 13. The sensor presents the expected tendency for the charge process in lead-acid batteries: in the top area of the battery, due to the electrolyte stratification, the density and viscosity do not increase their values significantly until the charge process is advanced and bubbling occurs [2,22].

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