Resolution in QCM Sensors for the Viscosity and Density of Liquids: Application to Lead Acid Batteries

Sensors

Ana Mar໚ Cao-Paz²  Loreto Rodríguez-Pardo¹  José Fari༚² 

[1] Department of Electronic Technology, University of Vigo, Campus Lagoas Marcosende, Vigo 36310, Spain;

关键词: quartz crystal microbalance;    lead-acid batteries;    state of charge;    density-viscosity product measurement;    sensitivity;    frequency noise;    resolution;   

DOI  :  10.3390/s120810604

来源: mdpi

【 摘 要 】

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 H₂SO₄ 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 productmeasurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.