This section provides an overview for capacitive proximity sensor as well as their applications and principles. Also, please take a look at the list of 8 capacitive proximity sensors manufacturers and their company rankings.
Table of Contents
Capacitive Proximity Sensors are a type of non-contact sensor that detect the presence or absence of an object. They can detect an object by the change in capacitance when the object enters the electric field.
Various substances can be detected, including metal, water, oil, glass, plastic, and paper. It can also detect the contents of non-metallic containers from the outside.
However, it should be noted that detection sensitivity and distance vary depending on the object's object size, thickness, and non-dielectric constant, as well as its susceptibility to water and moisture.
Capacitive Proximity Sensors are used for detecting the contents of a container from the outside and for non-contact switching.
Capacitive Proximity Sensors are capable of detecting liquids, paper, glass, and wood behind walls, inside tanks, inside containers, and behind covers. They are mainly used for inspection and confirmation of contents.
They are used as push-button switches in elevators, switches through various panels, etc., and non-contact switches for lights, etc. They are also applied to switches for lighting and dimming room lamps in cars.
The principle of capacitive proximity sensors is that an object can be detected by the change in capacitance when the object enters an electric field.
When voltage is applied to an electrode and the ground, an electric field is formed between the electrode and the ground. When an object enters the electric field formed by the electrodes, the object is charged by electrostatic induction and the electrode's capacitance changes.
Capacitive Proximity Sensors have a sensing electrode. When a dielectric detector enters the electric field formed by the sensing electrode, the electrode forms a capacitor with the object. The capacitance is determined by the distance to the object.
An oscillation circuit is commonly used for the detection circuit. The oscillation amplitude changes as the capacitance of the sensing electrode changes. An object is detected by comparing the amplitude changes that the oscillation circuit starts and stops. In capacitive proximity sensors, the sensing electrode is the element and oscillates.
An oscillation circuit is an electric circuit that generates electrical repetitive oscillations. An RC circuit consisting of a capacitor (C) and a resistor (R) is used to generate oscillations with frequencies ranging from 1/1,000 to several MHz.
CR oscillation is an oscillation circuit called a feedback type. A portion of the output of the amplifier circuit is fed back to the input to produce regular voltage fluctuations. The CR oscillation circuit rotates the phase of the amplifier output 180 degrees and returns it to the input.
The use of a high-frequency oscillation circuits may cause mutual interference when proximity sensors are nearby. When multiple sensors are installed, they should be installed at a distance greater than the specified distance.
Changes in capacitance are related to the size, thickness, and non-dielectric constant of the object. The larger each of these values is, the larger the capacitance will be.
Dielectric constant is an inherent electrical constant possessed by each material. The value of the dielectric constant is determined by how the electrons in each material respond to an external electric field. The non dielectric constant is expressed as the ratio of the dielectric constant of the material to the dielectric constant of a vacuum.
Because of its susceptibility to water and moisture, selection and installation considerations are important.
When a standard sensing element is brought close to the sensing surface, the distance from the sensing surface to the sensing element when the switch of the capacitive proximity sensor operates is called the sensing distance. When the detector is moved away from the sensor switch during the detection operation, the switch returns to its original position. At this time, the distance between the sensing surface and the detector is called the return distance.
Hysteresis is the ratio of the difference between the return distance and the detection distance, and is one of the indicators of detection characteristics of capacitive proximity sensors. The hysteresis is approximately 1 to 15% of the sensing distance.
*Including some distributors, etc.
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Rockwell Automation, Inc. was founded in 1903 and is headquartered in Milwakee, WI. Rockwell Automation provides industrial automation and digital transformation solutions around the world. Rockwell Automation operates through their intelligent devices, software & control, and lifecycle services segments with both hardware and software products and services. The Intelligent Devices segment offers drives, motion, safety, sensing, industrial components, and configured-to-order products. The Software & Control segment provides control and visualization software and hardware, information software, and network and security infrastructure solutions. The Lifecycle Services segment provides consulting, professional services and solutions, and connected and maintenance services through independent distributors.
AutomationDirect.com was founded in 1994 to provide solutions for the industrial automation market and has been growing its list of offerings ever since. AutomationDirects’ extensive catalog includes individual components such as cables, various controls, I/O devices, relays, gauges, fittings, and sensors to complete systems. Many parts and devices, especially PLC units are customizable. AutomationDirect.com also provides support via video instructions, online manuals, a learning library, an active community forum to further assist customers.
Baumer Electric AG was founded in 1952 and is headquartered in the city of Frauenfeld, Switzerland. The ISO 9001 and ISO 14001 certified company provides sensor solutions for digitalization, packaging, railway, food and beverage, and pharmaceutical industries. A sample of the company’s sensor product listings includes object detection, distance measurement, force sensors, accessories, and connectivity devices. The company offers product support for setup and installation, product functionality, and optimized product usage.
Eaton Corporation plc was founded in 1911 and is based in Dublin, Ireland. Eaton operates as a global power management company, providing electrical components, industrial components, power distribution and assemblies as well as industrial applications. The company’s vehicles segment also offers transmissions, hybrid power systems, and fuel vapor components for the vehicle industry. The company’s eMobility segment offerings include voltage inverters, power distribution systems, and commercial vehicle hybrid systems. The company also provides engineering and repair services.
Ranking as of June 2023 Globally
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | dol-sensors A/S | 12.5% |
2 | Zhejiang Hugong Automation Technology Co. , Ltd. | 12.5% |
3 | di-soric | 12.5% |
4 | AutomationDirect | 12.5% |
5 | Baumer | 12.5% |
6 | Rockwell Automation | 12.5% |
7 | Eaton | 12.5% |
8 | SICK Inc. | 12.5% |
Derivation Method
The ranking is calculated based on the click share within the capacitive proximity sensors page as of June 2023. Click share is defined as the total number of clicks for all companies during the period divided by the number of clicks for each company.Number of Employees
Newly Established Company
Company with a History
34 products are listed.
Capacitive proximity sensors for position detection or level monitoring. Easily adjust the empty/full state with a push button ・
Capacitive proximity sensors for position detection or level monitoring. Easily adjust the empty/full state with a push button ・
Capacitive proximity sensors for position detection or level monitoring. Easily adjust the empty/full state with a push button ・