Search query: level capacitive sensor

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abstract: Measurement of moisture at ppm or ppb level is very difficult and the fabrication of such sensors at low cost is always challenging. High sensitivity is an important parameter for trace level (ppm) humidity sensors. Anelectronic detection circuit for interfacing the humidity sensor with high sensitivity requires a simple hardware circuit with few active devices. The recent trends for increasing the sensitivity include fabricating nanoporous film with a very large surface area. In the present work, the sensitivity of a parallel plate capacitive type sensor with metal oxide sensing film has been significantly improved with an aim to detect moisture from 3 to 100 ppm in the industrial process gases used to fabricate semiconductors and other sensitive electronic devices. The sensitivity has been increased by (i) fabricating a nanoporous film of aluminum oxide using the sol gel method and (ii) increasing the cross sectional area of a parallel plate capacitor. A novel double sided capacitive structure has been proposed where two capacitors have been fabricated one on the top and one on the bottom side of a flat alumina substrate and then the capacitors are connected in parallel. The structure has twice the sensitivity of a single sensor in the same ppm range but the size of the structure remains unchanged. The important characteristics of the sensors such as the sensitivity (S D C D p p m x 100 the response time (tr) and the recovery time (tc) are determined and compared with a commercial SHAW, UKdew point meter. The fabricated double sided sensor has comparable sensitivity (S 100% tr (s) 28, tc (s) 40) with the commercial meter (S 100.5% tr (s) 258) but has a faster response time. The proposed method of sensitivity enhancement is simple, and mass producible.
author_names: Lokesh Kumar

Tarikul Islam

Subhas Chandra Mukhopadhyay
title: Sensitivity Enhancement of a PPM Level Capacitive Moisture Sensor
year: 2017

abstract: In the present study a real time capacitive sensor based on a capacitance step method is designed, developed and applied on measuring the liquid level by immersion. The capacitive sensor consists of two electrodes from copper plated phenolite plates separated by a gap distance and mounted inside a non conductive storage tank. Water is used as the dielectric material. The analyzed sensor behavior with liquid level variation is semi linear and obtained in function of the output voltage variation by using proper signal conditioning circuit. For converting the voltage variation into level variation, a parallel R C circuit is used instead of conventional bridge circuit. Under suitable parameter settings it provided good reading accuracy. The experimental results demonstrate the high efficiency of the proposed model, which confirm the satisfactory performance of the capacitive sensor for liquid level measurement. The sensor presents an excellent ease of construction and installation, linked to the good measurements precision and high autonomy of system operation. The behavior experiments under different salt concentrations show that the water chemical composition does not interfere on the sensor operation. The proposed model exhibits a promising employment in several applications, such as control equipment for irrigation, biomedical area in the interaction between antibody antigen or protein DNA, aerospace and pharmaceutical industry, gas sensors, and automation solutions.
author_names: R T Bento

Roger W O Silva

Lucas Alves Dias

Andre Ferrus Filho

Antonio Pitta
title: Design, development and application of a real time capacitive sensor for automatically measuring liquid level
venue: SN Applied Sciences
year: 2019

abstract: Liquid level measurement is important requirement for building and industrial applications. One of the most popular methods for level measurement is the capacitive sensor. Most of the capacitive sensors are contact type which suffer from frequent maintenance, and drift of the sensor output. Present paper proposes a simple noncontact interdigitated fringing field capacitance sensor for liquid level measurement. Three different interdigitated (IDT) sensors have been designed, simulated (finite element method) and fabricated to measure water level from 0 to 40 mm. The capacitance value of all the three sensors vary almost linearly with the variation of liquid level. Experimental results show that the sensitivity of the 1 5 1 IDT sensor is 0.0398 pF/mm. The sensor is capable to detect water level with resolution of 0.1 mm
author_names: Tarikul Islam

Om Prakash Maurya
title: Design and fabrication of non contact fringing field capacitive sensor for liquid level measurement
venue: 2019 IEEE 16th India Council International Conference (INDICON)
year: 2019

abstract: Present work describes the design and development of nonsubmersible capacitive sensor for liquid level detection. The prototype implementation is done using glass container. Aluminum strips on the outer surface of the container forms the capacitor. The change in water level inside the container, changes the capacitance value. This changes the signal frequency which is analyzed using microcontroller. Hence, this proposed prototype successfully detects the change in level of water without submersing the sensor inside the container.
author_names: Amit Patwardhan

P N Vishwanathan

Jayant Pawar

Ashish kumar Patel

Rabinder Henry

Pratik More
title: Development of Non Submersible Capacitive Sensor for Water Level Detection
year: 2019

abstract: Hoppers and silos are the integrated part of various industrial processes. Hoppers or silos are used mainly as a temporary storage of the product or by product from the industrial processes. Level measurement in hoppers is a crucial task due to temperature and dusty environment. Various techniques like optical laser based sensors, ultrasonic sensors, strain gauge based sensors etc. are used for level measurement in the hoppers/silos. But for cement or ash level measurement, due to dusty environment ultrasonic sensors and optical sensors are not advisable. Strain gauge based sensors are also not advisable as it work on the physical deformation of the sensor so it has relatively small life cycle. A non contact type capacitive sensor design is proposed and experimentally evaluated for level measurement in hopper/silos. The calculation for the non parallel portion of the hopper is also presented in this work. The present design in free from any parasitic capacitances and the outer metallic body of the hopper is used as shield for the capacitive sensor. The experiments are performed for cement clinkers and fly ash and the results are presented.
author_names: Amithab Pal

Urandur Pavan Kalyan

Ch Harika

B Vasuki
title: Capacitive Sensor for Level Measurement in Hopper/Silos Experimental Evaluation
venue: 2019 2nd International Conference on Intelligent Computing, Instrumentation and Control Technologies (ICICICT)
year: 2019

abstract: BACKGROUND: Drinking water has several advantages that have already been established, such as improving blood circulation, reducing acid in the stomach, etc. However, due to people not noticing the amount of water they consume every time they drink, most people drink less water than the recommended daily allowance. OBJECTIVE: In this paper, a capacitive sensor for developing an automatic tumbler to measure water level is proposed. Different than in previous studies, the proposed capacitive sensor was separated into two sets: the main sensor for measuring the water level in the tumbler, and the reference sensor for measuring the incremental level unit. METHODS: In order to confirm the feasibility of the proposed idea, and to optimize the shape of the sensor, a 3D model of the capacitive sensor with the tumbler was designed and subjected to Finite Element Analysis (FEA) simulation. According to the simulation results, the electrodes were made of copper and assembled in a tumbler manufactured by a 3D printer. The tumbler was filled with water and was subjected to experiments in order to assess the sensor's performance. RESULTS: The comparison of experimental results to the simulation results shows that the measured capacitance value of the capacitive sensor changed linearly as the water level varied. This proves that the proposed sensor can accurately measure the water level in the tumbler. Additionally, by use of the curve fitting method, a compensation algorithm was found to match the actual level with the measured level. CONCLUSIONS: The experimental results proved that the proposed capacitive sensor is able to measure the actual water level in the tumbler accurately. A digital control part with micro processor will be designed and fixed on the bottom of the tumbler for developing a smart tumbler.
author_names: Qun Wei

Mi-Jung Kim

Jong-Ha Lee
title: Development of capacitive sensor for automatically measuring tumbler water level with FEA simulation
venue: Technology and health care official journal of the European Society for Engineering and Medicine
year: 2018

abstract: Paper presents a technique for simultaneous measurement of liquid temperature along with level of liquid using capacitive level sensor and estimators/ soft sensors. The objective of the proposed work is to develop an estimator for measuring the liquid temperature in a process tank by analyzing the available capacitive level sensor. Input output behavior of the capacitive level sensor is analyzed for variation in liquid level and temperature variations. A non parametric soft sensor is designed using artificial neural network and fuzzy logic techniques are used to compute the relation between the capacitive level sensor outputs for variations in liquid temperature. The designed measurement technique is validated by performing the experiment in simulation and on practical setup. Results obtained by the technique shows successful implementation of proposed soft sensor.
author_names: Santhosh Kv

Manik Gupta
title: Simultaneous Measurement of Liquid Level and Temperature Using Capacitive Sensor
venue: 2018 2nd International Conference on Trends in Electronics and Informatics (ICOEI)
year: 2018

abstract: Ink printing is utilized to develop a coplanar capacitive senor with microscale electrodes, which exhibits high sensitivity. The sensor's capacitance has been theoretically and experimentally correlated to the water resistivity. As a cost effective, portable and reusable sensor, its application for water level measuring and quality monitoring has been demonstrated.
author_names: Qiang Yang

Andrew Junfang Yu

James L Simonton

Gaoqiang Yang

Yeshi Dohrmann

Zhenye Kang

Yifan Li

Jingke Mo

Feng-Yuan Zhang
title: An inkjet printed capacitive sensor for water level or quality monitoring: investigated theoretically and experimentally
year: 2017

abstract: In this paper, characterization of sensitive contact less coplanar capacitive liquid level sensors realized by polymer thick film technology is presented. It was found out that polymer thick film coplanar capacitive sensors are suitable for use in liquid level sensing application realized by contactless sensing method. Principle of measurement by using contact less capacitive sensing method and performance of realized liquid level sensors are described in this paper. Design optimization of various geometric dimension of comb sensor structures was compared and analyzed for easy construction of very sensitive contact less coplanar capacitive liquid level sensor. Thick film coplanar capacitive sensor is suitable, cost effective and reusable alternative for contact less level measurement of various liquids with different dielectric constant.
author_names: Alena Pietrikova

Samuel Zuk

Igor Vehec
title: Coplanar Capacitive Liquid Level Sensor
venue: 2019 42nd International Spring Seminar on Electronics Technology (ISSE)
year: 2019

abstract: Abstract This paper presents the design and fabrication of a liquid level measurement system based on a grounded cylindrical capacitive sensor for conductive liquids. Fabrication of the cylindrical capacitive sensor is performed with a novel approach of shielded cable. The inner conductor of shielded cable is connected to ground and the outer conductor is used to measure the liquid level. The relationship between the capacitance value of the cylindrical capacitive sensor and the liquid level is deduced by the analysis and calculation of physical parameters. Moreover, a backward difference calculation is adopted in order to offset the effects of the parasitic capacitance. The performance of the system has been experimentally tested in both grounded metallic and plastic containers. The experimental results show that the nonlinear error is smaller than 5 mm over a range of 90 cm. Over a wide measuring range of 200 cm, the liquid level measurement system has a nonlinear error smaller than 1.35 cm.
author_names: Bao-quan Jin

Zeyu Zhang

Hong-juan Zhang
title: Structure design and performance analysis of a coaxial cylindrical capacitive sensor for liquid level measurement
year: 2015