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

QCM sensor placed inside the battery during real time measurements.
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f5-sensors-12-10604: QCM sensor placed inside the battery during real time measurements.

Mentions: A study of short term stability was carried out with the sensor inside the battery, given that the operating conditions of the quartz are different from those in the controlled trial with sulfuric acid solutions. Inside the battery, the environment can be turbid due to suspended particles. This can produce instabilities in the sensor. In order to estimate this effect and any other that could produce frequency noise, it is desirable to know the resolution of the sensor inside the battery. Moreover, after thermal compensation, it is interesting to know the frequency noise. The resonator was placed inside a battery cell in the top area of a battery with a SoC of 99% (Figure 5). The temperature of the electronic oscillator was maintained constant at 42 °C, but the electrolyte was at room temperature (temperature of the battery). Oscillation frequency, temperature of the electrolyte and temperature of the electronic oscillator were sampled every 2 s over four days. Temperature compensation was carried out and Allan deviation and resolution were determined in real conditions for application of the SoC QCM sensor.


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)

QCM sensor placed inside the battery during real time measurements.
© Copyright Policy
Related In: Results  -  Collection

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

f5-sensors-12-10604: QCM sensor placed inside the battery during real time measurements.
Mentions: A study of short term stability was carried out with the sensor inside the battery, given that the operating conditions of the quartz are different from those in the controlled trial with sulfuric acid solutions. Inside the battery, the environment can be turbid due to suspended particles. This can produce instabilities in the sensor. In order to estimate this effect and any other that could produce frequency noise, it is desirable to know the resolution of the sensor inside the battery. Moreover, after thermal compensation, it is interesting to know the frequency noise. The resonator was placed inside a battery cell in the top area of a battery with a SoC of 99% (Figure 5). The temperature of the electronic oscillator was maintained constant at 42 °C, but the electrolyte was at room temperature (temperature of the battery). Oscillation frequency, temperature of the electrolyte and temperature of the electronic oscillator were sampled every 2 s over four days. Temperature compensation was carried out and Allan deviation and resolution were determined in real conditions for application of the SoC QCM sensor.

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