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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

Relation between Allan deviation and .
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f9-sensors-12-10604: Relation between Allan deviation and .

Mentions: In Table 1, the experimental quality factor, Allan deviation, detection limit and resolution obtained for each pair (each frequency step in Figure 6) are indicated. These results show that the noise is higher than the minimum attainable using Equation (9) perhaps because of problems of circuitry. The resolution decreases slightly when increases, because quality factor and therefore noise tendency becomes greater with as expected for a given nominal frequency. Figures 8 and 9 show this tendency. The greatest value of the Allan deviation (8.8 × 10−8) represents the worst case. In this situation, the experimental quality factor, Qexp, is 1,279 and a resolution of can be achieved. With this resolution, the QCM sensor can detect SoC changes in the battery of about 0.1% with a measurement interval of 2 s.


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)

Relation between Allan deviation and .
© Copyright Policy
Related In: Results  -  Collection

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

f9-sensors-12-10604: Relation between Allan deviation and .
Mentions: In Table 1, the experimental quality factor, Allan deviation, detection limit and resolution obtained for each pair (each frequency step in Figure 6) are indicated. These results show that the noise is higher than the minimum attainable using Equation (9) perhaps because of problems of circuitry. The resolution decreases slightly when increases, because quality factor and therefore noise tendency becomes greater with as expected for a given nominal frequency. Figures 8 and 9 show this tendency. The greatest value of the Allan deviation (8.8 × 10−8) represents the worst case. In this situation, the experimental quality factor, Qexp, is 1,279 and a resolution of can be achieved. With this resolution, the QCM sensor can detect SoC changes in the battery of about 0.1% with a measurement interval of 2 s.

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