Industrial sensors are various sensors used in industrial manufacturing processes such as energy, petroleum, chemical, metallurgy, power, machinery manufacturing, and automobiles. They generally refer to devices and apparatuses that can convert measured forces, heat, light, magnetism, sound, humidity, electricity, and environmental factors into electrical signals for output during industrial manufacturing processes.
Deploying sensors and sensing technologies offers numerous advantages, including predictive and preventative maintenance. They not only ensure faster transmission of measurement data but also improve accuracy, thereby enhancing process control and improving asset health. New sensors, capable of both wired and wireless transmission, provide real-time, continuous data feeds from assets and processes. This allows managers to gain a more comprehensive understanding of the process plant. Businesses leveraging sensors are more connected, secure, and agile than ever before.
I. Photoelectric Sensors
A photoelectric sensor is a device that converts light signals into electrical signals. Its working principle is based on the photoelectric effect. The photoelectric effect refers to the phenomenon where, when light shines on certain materials, the electrons in the material absorb the energy of the photons, resulting in a corresponding electrical effect. Based on different phenomena, the photoelectric effect is divided into three categories: external photoelectric effect, internal photoelectric effect, and photovoltaic effect. Photoelectric devices include phototubes, photomultiplier tubes, photoresistors, photodiodes, phototransistors, and photovoltaic cells.
II. Proximity Sensor
A proximity sensor is a general term for sensors that replace contact-based detection methods such as limit switches, aiming to detect objects without physical contact. It detects the movement and presence of an object and converts this information into electrical signals. A proximity sensor is a device capable of sensing the approach of an object. It utilizes the sensitivity of displacement sensors to approaching objects to identify their proximity and outputs a corresponding switching signal; therefore, proximity sensors are often also called proximity switches.
III. Temperature Sensor
A temperature sensor is a sensor that senses temperature and converts it into a usable output signal. It is the core component of temperature measuring instruments and comes in a variety of types. Temperature sensors can be broadly classified into two categories based on their measurement method: contact and non-contact. Contact temperature sensors, also known as thermometers, have their sensing element in good contact with the object being measured. Thermometers achieve thermal equilibrium through conduction or convection, allowing the reading to directly represent the temperature of the measured object; they generally offer high measurement accuracy. Temperature sensors are highly accurate in measuring ambient temperature and are widely used in workshops, warehouses, agriculture, and industry.
IV. Pressure Sensor
Pressure sensors are commonly used sensors widely applied in various industrial automation environments. Taking the petrochemical industry as an example, pressure sensors are among the most frequently used measuring devices in its automatic control systems. Large-scale chemical projects encompass almost all applications of pressure sensors: absolute pressure, differential pressure, gauge pressure, high pressure, micro differential pressure, and remote flange-type pressure sensors made of various materials and with special processing. It is worth noting that with the development of the medical equipment market, higher requirements are being placed on pressure sensors used in the medical industry, such as improvements needed in accuracy, size, stability, and reliability.
V. Liquid Level Sensor
Liquid level refers to the height of the liquid in a sealed container (e.g., a water tank) or an open container (water tank). In daily life and industrial production, it is frequently necessary to know the liquid level inside containers. In some cases, this is due to factors such as the container being too large, inconvenient access for personnel, or the container material not being transparent. In these situations, a liquid level sensor is required. The liquid level sensor converts the liquid level signal inside the container into a switching signal or a voltage/current signal, and then, through external circuitry, allows the observer to directly and accurately determine the liquid level inside the container.
VI. Fiber Optic Sensors
A fiber optic sensor is a sensor that converts the state of a measured object into a measurable optical signal. The working principle of a fiber optic sensor is to send a light beam incident from a light source through an optical fiber into a modulator. Within the modulator, the light interacts with the external measured parameters, causing changes in the optical properties of the light, such as intensity, wavelength, frequency, phase, and polarization state, resulting in a modulated optical signal. This modulated signal is then sent through an optical fiber to a photoelectric device and, after passing through a demodulator, the measured parameters are obtained.
After more than half a century of development, my country's industrial sensor industry has made certain progress in terms of systems, scale, product variety, basic technology research, and innovative industrial application formats, basically meeting the needs of the rapidly developing national economy since the reform and opening up. However, it is worth noting that the industry itself still faces challenges such as weak innovation capabilities, a lack of core technologies, and a low rate of commercialization of core component research results. It is believed that after overcoming these challenges, my country's sensor industry will achieve even greater development results.
