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. 2016 Jan 27;16(2):165.
doi: 10.3390/s16020165.

New C4D Sensor with a Simulated Inductor

Yingchao Lyu  1 , Haifeng Ji  2 , Shijie Yang  3 , Zhiyao Huang  4 , Baoliang Wang  5 , Haiqing Li  6
Affiliations

New C4D Sensor with a Simulated Inductor

Yingchao Lyu et al. Sensors (Basel). .

Abstract

A new capacitively coupled contactless conductivity detection (C(4)D) sensor with an improved simulated inductor is developed in this work. The improved simulated inductor is designed on the basis of the Riordan-type floating simulated inductor. With the improved simulated inductor, the negative influence of the coupling capacitances is overcome and the conductivity measurement is implemented by the series resonance principle. The conductivity measurement experiments are carried out in three pipes with different inner diameters of 3.0 mm, 4.6 mm and 6.4 mm, respectively. The experimental results show that the designs of the new C(4)D sensor and the improved simulated inductor are successful. The maximum relative error of the conductivity measurement is less than 5%. Compared with the C(4)D sensors using practical inductors, the measurement accuracy of the new C(4)D sensor is comparable. The research results also indicate that the adjustability of a simulated inductor can reduce the requirement for the AC source and guarantee the interchangeableness. Meanwhile, it is recommended that making the potential of one terminal of a simulated inductor stable is beneficial to the running stability. Furthermore, this work indirectly verifies the possibility and feasibility of the miniaturization of the C(4)D sensor by using the simulated inductor technique and lays a good foundation for future research work.

Keywords: capacitively coupled contactless conductivity detection (C4D); conductivity measurement; contactless conductivity detection (CCD); series resonance; simulated inductor.

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Figures

Figure 1
Figure 1
Principle of a typical C4D sensor: (a) Construction; (b) Equivalent circuit; (c) Simplified equivalent circuit; (d) Further simplified equivalent circuit.
Figure 2
Figure 2
Simplified circuit of the C4D sensor based on series resonance.
Figure 3
Figure 3
Circuit of the improved simulated inductor.
Figure 4
Figure 4
Measurement principle of the new C4D sensor: (a) Construction; (b) Equivalent circuit; (c) Simplified equivalent circuit.
Figure 5
Figure 5
Experimental setup for conductivity measurement.
Figure 6
Figure 6
Conductivity measurement results of three new C4D sensors: (a) 3.0 mm i.d.; (b) 4.6 mm i.d.; (c) 6.4 mm i.d.
Figure 7
Figure 7
Sensitivity plots of the new C4D sensor with 3.0 mm i.d. and the conventional C4D sensor with 3.0 mm i.d.
Figure 8
Figure 8
Construction of the supplementary C4D sensor.
Figure 9
Figure 9
Output signals: (a) Supplementary C4D with 3.0 mm i.d.; (b) New C4D sensor with 3.0 mm i.d.
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References

    1. Tower O.F. The Conductivity of Liquids: Methods, Results, Chemical Applications and Theoretical Considerations. Chemical Publishing Company; Easton, PA, USA: 1905.
    1. De Diego A., Usobiaga A., Fernandez L.A., Madariaga J.M. Application of the electrical conductivity of concentrated electrolyte solutions to industrial process control and design: From experimental measurement towards prediction through modeling. Trends. Anal. Chem. 2001;20:65–78. doi: 10.1016/S0165-9936(00)00081-9. - DOI
    1. Bard A.J., Faulkner L.R. Electrochemical Methods Fundamentals and Application. John Wiley & Sons, Inc.; New York, NY, USA: 2001.
    1. Hamann C.H., Hamnett A., Vielstich W. Electrochemistry. 2nd ed. Wiley-VCH Verlag GmbH & Co.KGaA; Weinheim, Germany: 2007.
    1. Pumera M. Contactless conductivity detection for microfluidics: Designs and applications. Talanta. 2007;74:358–364. doi: 10.1016/j.talanta.2007.05.058. - DOI - PubMed

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