Capacitance level gauge

Abstract

A capacitive level meter consisting of a printed circuit board with holes, on which a microcontroller with an ADC and built-in communication modules is installed, a cable of insulated electrodes, wherein some of the insulated electrodes are connected to the analog-to-digital converters of the microcontroller's capacitance, and the level meter is designed with the ability to measure the capacitance, which changes when the insulated electrodes are immersed in the measured medium, wherein some of the electrodes are connected to the ADC using sensor cables, and one electrode is used as "ground", wherein the microcontroller contains software for processing the analog signal and converting the received data into centimeters and has the ability to transmit data via wireless communication channels.

Description

[0001] Technical field

[0002] The utility model relates to the field of measuring technology and is intended to monitor the water level in irrigation and hydroponic systems, in sewage systems and treatment facilities, in polluted water bodies and in areas after environmental disasters.

[0003] Technology Level

[0004] A device for measuring the liquid level using the Espressif ESP32 microcontroller is known from the prior art [Electronic resource] / / URL: (see https: / / web.archive.org / web / 20230314165441 / https: / / www.youtube.com / watch?v=ZPPrDsZpM34), date of posting on the Internet: 03 / 14 / 2023 (date of access 04 / 23 / 2025), consisting of two strips of foil and an ESP32 / -S2 / -S3 series microcontroller, which allows, using the hardware interface of capacitive sensors, to determine the liquid level in a polymer or glass vessel, while the foil is glued to the outside of the vessel and there is no contact with the liquid.

[0005] The disadvantages of this device are that the electrodes are located outside the tank. Therefore, it is impossible to measure the liquid level in a pond or buried tank, or in tanks that are not accessible from the outside. It is also impossible to measure the liquid level in a metal tank.

[0006] Disclosure of Utility Model

[0007] The technical result of the claimed utility model is the creation of a measuring device for monitoring the level of an electrically conductive liquid, for example, water, namely clean water and, in extreme conditions, heavily polluted water, for example, heavily polluted sewage water, and which requires virtually no regular maintenance.The above technical result is achieved by a capacitive level meter consisting of a printed circuit board with holes, on which a microcontroller with an ADC and built-in communication modules is installed, a cable of insulated electrodes, wherein part of the insulated electrodes is connected to analog-to-digital converters of the microcontroller's capacitance, and the level meter is designed with the ability to measure the capacitance, which changes when the insulated electrodes are immersed in the measured medium, wherein part of the electrodes are connected to the ADC using sensor cables, and one electrode is used as "ground", wherein the microcontroller contains software for processing the analog signal and converting the received data into centimeters and has the ability to transmit data via wireless communication channels.

[0008] Brief description of drawings

[0009] Fig. 1 shows a general view of the claimed device from above.

[0010] Fig. 2 shows a general view of the claimed device from the front.

[0011] Implementation of a utility model

[0012] The claimed utility model is a capacitance level meter consisting of a printed circuit board 1 with mounting holes 2, on which a microcontroller 3 with a built-in ADC and integrated wireless communication modules is mounted, and a cable of insulated electrodes 4. The cable measures the capacitance between several insulated electrodes connected to the microcontroller's capacitance analog-to-digital converters (ADCs) when they are immersed in a medium of varying depths, each performing a specific function, ensuring the accuracy and reliability of the measurements. There are two electrodes. The microcontroller's ADC or external ADCs are used to measure the capacitance, allowing the depth of the medium in which the electrodes are immersed to be determined.

[0013] The insulated electrodes prevent oxidation and other negative factors that could reduce their service life. The capacitance between the electrodes changes depending on the immersion depth, allowing the level of the medium to be determined relative to the electrode position. The measurement data is then processed and approximated using a hyperbolic mathematical model to improve the accuracy and reliability of the measurements. The operation of a capacitance level meter for contaminated media is as follows.

[0014] The device is immersed in liquid, and the microcontroller's ADC reads the electrical signals from the electrodes and converts them into capacitance values. Software in the microcontroller processes the raw data and converts it into centimeters. Equipped with an integrated controller and the ability to transmit data via wired or wireless communication channels, this sensor is ideal for continuous remote monitoring. Data from the device is accessible through a dedicated app or can be integrated with external systems via an API or wired, providing maximum flexibility for custom applications. Filtering and data averaging methods play an important role in capacitance measurement, helping to reduce the influence of noise and improve measurement accuracy. A hyperbolic function or linear approximation can be used to describe the dependence of capacitance change on depth.The hyperbola parameters are selected in such a way as to most accurately reflect the nature of the change in capacitance depending on the immersion depth of the electrodes.

[0015] Depending on the type of cables used and their electrical characteristics, both the data filtering methods and the hyperbola approximation parameters may need to be adjusted. For example, for UTP cable, filter thresholds may need to be adjusted and the hyperbola parameters may need to be adjusted to achieve maximum measurement accuracy.

[0016] Hyperbola parameter adaptation can include adjustments to parameters such as amplitude, offset, and scale based on calibration measurements or using machine learning algorithms. This allows the model to be refined to account for specific operating conditions and device design features.

[0017] Thus, the principles of measurement and data processing in capacitive depth measurement devices involve a complex set of filtering, averaging, and data approximation methods. Using these methods significantly improves the accuracy of capacitance measurements and, consequently, depth.

[0018] In addition to filters and approximation, the correct selection of cable types, their coating, and adaptation of the measurement system parameters to specific operating conditions are crucial. Developing a measurement system involves not only selecting appropriate filtering methods and hyperbola parameters but also ensuring their dynamic adjustment based on changing environmental conditions or component wear. This can be achieved through the introduction of self-learning or adaptation algorithms that, based on the analysis of collected data, adjust the filtering and approximation parameters, thereby ensuring high reliability and accuracy of the device throughout its service life.

[0019] Regular calibration and drift compensation algorithms help maintain high measurement accuracy over a long period of time, especially in conditions of changing temperature and environmental pollution.

[0020] In some applications, particularly when working with liquids, optimizing the shape and placement of electrodes can significantly improve measurement accuracy by reducing the influence of boundary effects and ensuring uniform field distribution.

[0021] Advanced signal processing, including filtering and time series analysis algorithms, can effectively filter out noise and improve measurement accuracy.

[0022] One of the key procedures for ensuring the reliability and accuracy of our devices is regular testing for short circuits between the electrodes. This prevents potential problems associated with damaged electrodes, which can lead to incorrect measurements. If a short circuit is detected, the algorithm excludes the damaged electrode from the measurements.

[0023] One of the key modifications to our capacitive depth measurement device is the use of electrodes of varying lengths. This improves measurement accuracy, as each electrode can be optimized for measurement within a specific depth range. Short electrodes are more sensitive to small changes in depth, ensuring high measurement accuracy at shallow depths, while longer electrodes allow for acceptable measurement accuracy at greater depths. This modification facilitates the device's adaptability to a wide range of operating conditions.

[0024] Using electrodes of different lengths requires adapting the depth approximation method based on capacitance measurements. Knowing the difference in electrode length allows us to automatically calibrate them, as the electrodes' capacitance changes dramatically when immersed in the medium.

Claims

This utility model pertains to measurement technology and is designed to monitor water levels in irrigation and hydroponic systems, sewerage systems, wastewater treatment plants, polluted water bodies, and areas following environmental disasters. The capacitive level meter consists of a perforated printed circuit board containing a microcontroller with an analog-to-digital converter (ADC) and integrated communication modules, a battery or rechargeable battery, and a cable of insulated electrodes. Some of the electrodes are connected to the ADC via sensor cables, while one electrode is connected to a digital ADC and serves as ground. The microcontroller also contains software for processing the analog signal and converting the received data into centimeters, and is capable of transmitting data via wired or wireless communication channels.The technical results of the claimed utility model are the creation of a measuring device for monitoring the level of an electrically conductive liquid, such as water, specifically clean water and, under extreme conditions, highly contaminated water, such as highly contaminated sewage water, requiring virtually no regular maintenance, as well as having low production costs, low operating costs, simple manufacture, flexible configuration and calibration, and convenient interfaces for transmitting processed data. 2 fig.

Images