Limits...
Design and implementation of an intrinsically safe liquid-level sensor using coaxial cable.

Jin B, Liu X, Bai Q, Wang D, Wang Y - Sensors (Basel) (2015)

Bottom Line: In this paper, an intrinsically safe liquid-level sensor system for flammable and explosive environments is designed and implemented.Additionally, the system is designed with characteristics of intrinsic safety by limiting the energy of the circuit to avoid or restrain the thermal effects and sparks.The test results demonstrate that over the measurement range of 1.0 m, the maximum nonlinearity error is 0.8% full-scale span (FSS), the maximum repeatability error is 0.5% FSS, and the maximum hysteresis error is reduced from 0.7% FSS to 0.5% FSS by applying software compensation algorithms.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No.79 Yingzexi Street, Taiyuan 030024, China. jbq_007@163.com.

ABSTRACT
Real-time detection of liquid level in complex environments has always been a knotty issue. In this paper, an intrinsically safe liquid-level sensor system for flammable and explosive environments is designed and implemented. The poly vinyl chloride (PVC) coaxial cable is chosen as the sensing element and the measuring mechanism is analyzed. Then, the capacitance-to-voltage conversion circuit is designed and the expected output signal is achieved by adopting parameter optimization. Furthermore, the experimental platform of the liquid-level sensor system is constructed, which involves the entire process of measuring, converting, filtering, processing, visualizing and communicating. Additionally, the system is designed with characteristics of intrinsic safety by limiting the energy of the circuit to avoid or restrain the thermal effects and sparks. Finally, the approach of the piecewise linearization is adopted in order to improve the measuring accuracy by matching the appropriate calibration points. The test results demonstrate that over the measurement range of 1.0 m, the maximum nonlinearity error is 0.8% full-scale span (FSS), the maximum repeatability error is 0.5% FSS, and the maximum hysteresis error is reduced from 0.7% FSS to 0.5% FSS by applying software compensation algorithms.

No MeSH data available.


Resistive circuit spark ignition curve.
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sensors-15-12613-f008: Resistive circuit spark ignition curve.

Mentions: As mentioned in Section 3.2.1, the normal operating current is approximately 100 mA. When a short-circuit fault occurs in the output terminal of the protection circuit, the current reaches the maximum value (Imax = 1.5 A). The function of minimum ignition current (MIC) IMIC and the power supply voltage UP is expressed as [21]:(12)IMIC=0.0564135e78.1433UPA,18V≤UP≤30Vwhere the voltage range of the power supply is from 18 V to 30 V and Equation (12) is available in the environment at methane concentrations of from 8% to 8.6%. The corresponding resistive circuit ignition curve is presented in Figure 8.


Design and implementation of an intrinsically safe liquid-level sensor using coaxial cable.

Jin B, Liu X, Bai Q, Wang D, Wang Y - Sensors (Basel) (2015)

Resistive circuit spark ignition curve.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507675&req=5

sensors-15-12613-f008: Resistive circuit spark ignition curve.
Mentions: As mentioned in Section 3.2.1, the normal operating current is approximately 100 mA. When a short-circuit fault occurs in the output terminal of the protection circuit, the current reaches the maximum value (Imax = 1.5 A). The function of minimum ignition current (MIC) IMIC and the power supply voltage UP is expressed as [21]:(12)IMIC=0.0564135e78.1433UPA,18V≤UP≤30Vwhere the voltage range of the power supply is from 18 V to 30 V and Equation (12) is available in the environment at methane concentrations of from 8% to 8.6%. The corresponding resistive circuit ignition curve is presented in Figure 8.

Bottom Line: In this paper, an intrinsically safe liquid-level sensor system for flammable and explosive environments is designed and implemented.Additionally, the system is designed with characteristics of intrinsic safety by limiting the energy of the circuit to avoid or restrain the thermal effects and sparks.The test results demonstrate that over the measurement range of 1.0 m, the maximum nonlinearity error is 0.8% full-scale span (FSS), the maximum repeatability error is 0.5% FSS, and the maximum hysteresis error is reduced from 0.7% FSS to 0.5% FSS by applying software compensation algorithms.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No.79 Yingzexi Street, Taiyuan 030024, China. jbq_007@163.com.

ABSTRACT
Real-time detection of liquid level in complex environments has always been a knotty issue. In this paper, an intrinsically safe liquid-level sensor system for flammable and explosive environments is designed and implemented. The poly vinyl chloride (PVC) coaxial cable is chosen as the sensing element and the measuring mechanism is analyzed. Then, the capacitance-to-voltage conversion circuit is designed and the expected output signal is achieved by adopting parameter optimization. Furthermore, the experimental platform of the liquid-level sensor system is constructed, which involves the entire process of measuring, converting, filtering, processing, visualizing and communicating. Additionally, the system is designed with characteristics of intrinsic safety by limiting the energy of the circuit to avoid or restrain the thermal effects and sparks. Finally, the approach of the piecewise linearization is adopted in order to improve the measuring accuracy by matching the appropriate calibration points. The test results demonstrate that over the measurement range of 1.0 m, the maximum nonlinearity error is 0.8% full-scale span (FSS), the maximum repeatability error is 0.5% FSS, and the maximum hysteresis error is reduced from 0.7% FSS to 0.5% FSS by applying software compensation algorithms.

No MeSH data available.