What is a Level Sensor and How Does It Work in Industrial Applications?

Imagine manually checking tank levels in industrial settings! Automation in industries would not exist without the invention of level sensors, which are key in precisely monitoring liquid inventory in the modern automated era.想象一下在工业环境中手动检查储罐液位的情景！如果没有液位传感器的发明，工业自动化将无从谈起，这种传感器在现代自动化时代对于精确监测液体库存至关重要。想象一下在工业环境中手动检查储罐液位的情景！如果没有液位传感器的发明，工业自动化将无从谈起，这种传感器在现代自动化时代对于精确监测液体库存至关重要。

Level sensors come in all shapes and sizes and have various detection capabilities. Depending on the application, they can detect a microliter change in the lab or a million-gallon change in a refinery. Finding the perfect level sensor requires an understanding of its working mechanism. There are radar, ultrasonic, capacitance, and pressure transducer-based level detectors, each offering unique applications and abilities.液位传感器种类繁多，形状各异，检测能力也各不相同。根据应用的不同，它们可以在实验室中检测到微升的变化，也可以在炼油厂中检测到百万加仑的变化。要找到完美的液位传感器，需要了解其工作原理。有雷达式、超声波式、电容式和压力传感器式液位检测器，每种都有独特的应用和能力。液位传感器种类繁多，形状各异，检测能力也各不相同。根据应用的不同，它们可以在实验室中检测到微升的变化，也可以在炼油厂中检测到百万加仑的变化。要找到完美的液位传感器，需要了解其工作原理。有雷达式、超声波式、电容式和压力传感器式液位检测器，每种都有独特的应用和能力。

The latest level sensor technology allows precise level measurements. It improves efficiency, control, monitoring, and product quality while significantly reducing waste. Selecting a level sensor requires considering factors such as the nature of the liquid, accuracy requirement, space constraints, range, and safety. This article will explain the basics of water level sensors and provide an in-depth understanding so readers can find a suitable device for their industrial application.

最新的液位传感器技术能够实现精确的液位测量。它提高了效率、控制、监测和产品质量，同时大幅减少了浪费。选择液位传感器时需要考虑液体的性质、精度要求、空间限制、量程和安全性等因素。本文将介绍水位传感器的基础知识，并提供深入的了解，以便读者能够为他们的工业应用找到合适的设备。最新的液位传感器技术能够实现精确的液位测量。它提高了效率、控制、监测和产品质量，同时大幅减少了浪费。选择液位传感器时需要考虑液体的性质、精度要求、空间限制、量程和安全性等因素。本文将介绍水位传感器的基础知识，并提供深入的了解，以便读者能够为他们的工业应用找到合适的设备。

1. Introduction to Level Sensors1. 液位传感器简介

Simple everyday devices, such as the coffee maker, washing machine, and toilet, also have water level sensors. These devices are critical for everyday tasks, from controlled brewing to preventing flush tank overflow.像咖啡机、洗衣机和马桶这类简单的日常设备也装有水位传感器。这些设备对于日常任务至关重要，从控制冲泡到防止冲水箱溢水都离不开它们。像咖啡机、洗衣机和马桶这类简单的日常设备也装有水位传感器。这些设备对于日常任务至关重要，从控制冲泡到防止冲水箱溢水都离不开它们。

While the average household sensor may not need ultra-high accuracy, level sensors in industrial settings must be accurate, precise, and reliable to ensure safe operations. Their maloperation can lead to financial, environmental, or, in the worst case, safety disasters. Let's dive into the definition and working mechanisms of level sensors.虽然普通家庭使用的传感器可能不需要超高精度，但在工业环境中，液位传感器必须准确、精密且可靠，以确保安全运行。其故障操作可能会导致经济损失、环境污染，甚至在最糟糕的情况下引发安全事故。让我们来深入了解液位传感器的定义和工作原理。

2. Definition of Level Sensors2. 液位传感器的定义

A level sensor detects the amount of liquid inside a container and calculates the quantity using pressure, sound, electrical, or optical signals. The sensor usually provides an electrical signal, which a controller translates into a perceivable level or volume measurement. Depending on the type of level sensor, its output can vary, and sometimes, it can be a physical output rather than an electrical signal.液位传感器可检测容器内的液体量，并通过压力、声波、电或光信号计算出液体的量。该传感器通常提供电信号，控制器将其转换为可感知的液位或体积测量值。根据液位传感器的类型，其输出可能有所不同，有时可能是物理输出而非电信号。

3. Understanding Specifications of Level Sensors3. 了解液位传感器的规格说明

There are many manufacturers of level sensors. However, all of them offer unique specifications that make them stand out. Some provide higher ingress protection, while others offer longer operational life. Understanding these specifications is vital to finding the adequate equipment for level detection. Let's begin!液位传感器的制造商众多。然而，它们都具有独特的规格，使其脱颖而出。有些提供更高的防护等级，而有些则具有更长的使用寿命。了解这些规格对于找到合适的液位检测设备至关重要。让我们开始吧！

- Application -应用程序

The usage scenario is an essential requirement for selecting a level sensor. You may be dealing with explosive, corrosive, acidic, caustic, radioactive, or biologically hazardous liquid. Therefore, ensuring your level sensor is compatible with the liquid is the prime objective. It is the key reason why manufacturers of level sensors highlight their detectors or sensors' applicability.使用场景是选择液位传感器的一项关键要求。您可能要处理易爆、腐蚀性、酸性、碱性、放射性或生物危害性的液体。因此，确保液位传感器与液体兼容是首要目标。这也是液位传感器制造商强调其探测器或传感器适用性的主要原因。使用场景是选择液位传感器的一项关键要求。您可能要处理易爆、腐蚀性、酸性、碱性、放射性或生物危害性的液体。因此，确保液位传感器与液体兼容是首要目标。这也是液位传感器制造商强调其探测器或传感器适用性的主要原因。

- Type ——类型

After we have finalized our application, we can decide which type of sensors is suitable for the correct application. There can be float switch, capacitance, optical, conductivity, tuning fork, ultrasonic, and radar sensors. All of them offer unique detection capabilities. The upcoming section will discuss the operating principles and purpose in detail.在我们确定好应用方案之后，就可以决定哪种类型的传感器适合正确的应用。可以选用浮球开关、电容式、光学、电导率、音叉、超声波和雷达传感器。它们都具有独特的检测能力。接下来的部分将详细讨论其工作原理和用途。在我们确定好应用方案之后，就可以决定哪种类型的传感器适合正确的应用。可以选用浮球开关、电容式、光学、电导率、音叉、超声波和雷达传感器。它们都具有独特的检测能力。接下来的部分将详细讨论其工作原理和用途。

- Range - - - - - -范围

Designers select the appropriate level sensors based on the container's size and the depth of liquid it houses. The range of a level sensor also depends on the type of level sensor, so it is essential to select the appropriate type. Manufacturers express range as length usually represented in meters (m).设计人员会根据容器的大小以及所容纳液体的深度来选择合适的液位传感器。液位传感器的量程还取决于液位传感器的类型，因此选择合适的类型至关重要。制造商通常以米（m）为单位来表示量程。

- Accuracy ——准确性

The application also determines the accuracy requirement. In pharmaceutical and biological applications, the accuracy can be as minimal as micrometers (µm). Manufacturers will mention accuracy as a percentage of full-scale (%FS) or millimeters (±mm). They define the error probability in your reading based on the level of sensor design or conditional limitations.该应用程序还会确定精度要求。在制药和生物应用中，精度可以低至微米（µm）。制造商通常会以满量程的百分比（%FS）或毫米（±mm）来提及精度。他们会根据传感器的设计水平或条件限制来定义您读数中的误差概率。

- Output ——输出

Manufacturers always mention the sensor output level, a vital specification for installers or designers setting up tanks in industrial applications. These sensors typically feature 2 to 4 wires, each providing a different output type.制造商总是会提及传感器的输出电平，这是安装人员或设计人员在工业应用中设置储罐时的一个重要规格。这些传感器通常具有 2 至 4 根导线，每根导线提供不同的输出类型。制造商总是会提及传感器的输出电平，这是安装人员或设计人员在工业应用中设置储罐时的一个重要规格。这些传感器通常具有 2 至 4 根导线，每根导线提供不同的输出类型。

Connecting the wire terminal at the other end to a Programmable Logic Controller (PLC), SCADA system, or industrial data logger. However, the analog input modules or data acquisition systems may vary depending on the design of the industrial control and monitoring system.将另一端的电线端子连接到可编程逻辑控制器（PLC）、监控和数据采集（SCADA）系统或工业数据记录仪。不过，模拟输入模块或数据采集系统可能会因工业控制和监测系统的设计而有所不同。将另一端的电线端子连接到可编程逻辑控制器（PLC）、监控和数据采集（SCADA）系统或工业数据记录仪。不过，模拟输入模块或数据采集系统可能会因工业控制和监测系统的设计而有所不同。

In a digital setup, multiple sensors can be connected in a daisy chain to a single RS485 controller device (such as a computer, PLC, or data logger). In this case, you will need a MODBUS software configuration to read and write data.在数字设置中，多个传感器可以串联连接到单个 RS485 控制器设备（如计算机、可编程逻辑控制器或数据记录仪）上。在这种情况下，您需要一个 MODBUS 软件配置来读取和写入数据。

- Temperature Range -温度范围

There is a level sensor for all, whether you are installing a level sensor in boiling water or liquid gas. Some level sensors are designed to withstand a wide temperature range. In most cases, a level sensor can work efficiently around 80°C, while in some extreme conditions, level sensors can work at 1000°C (1832°F) and pressures reaching 10,000 PSI. The end user must carefully evaluate their application to find the appropriate compatible sensor.无论您是在沸水中还是在液态气体中安装液位传感器，都有适合的液位传感器。有些液位传感器设计用于承受广泛的温度范围。在大多数情况下，液位传感器在约 80°C 时能高效工作，而在某些极端条件下，液位传感器可在 1000°C（1832°F）的温度和高达 10,000 磅/平方英寸的压力下工作。最终用户必须仔细评估其应用，以找到合适的兼容传感器。

- Protection ——保护

The sensor must have a protection rating if exposed to dust and water. Water level sensors come with IP ratings that represent their degree of protection. IP (Ingress Protection) is a two-digit number. The first digit represents protection against sand, and the second digit provides information on equipment for protection against water. A higher number means a higher rating. Similarly, they also mention protection against corrosive materials and acidic, caustic, or radioactive liquids.如果传感器暴露在灰尘和水中，就必须具备防护等级。水位传感器带有 IP 防护等级，代表其防护程度。IP（防护等级）是一个两位数。第一位数字表示防尘等级，第二位数字表示防水等级。数字越大，防护等级越高。同样，它们还提到对腐蚀性材料以及酸性、碱性或放射性液体的防护。

4. How Do Level Sensors Operate?4. 液位传感器是如何工作的？

We must define their working mechanism based on type to understand how level sensors work. Here are the four significant categories of level sensors and their operational details:为了理解液位传感器的工作原理，我们必须根据类型来定义它们的工作机制。以下是液位传感器的四大重要类别及其工作细节：

● Submersible Pressure Transducers● 潜水式压力传感器

Submersible pressure transducers are installed at the bottom of a container. They detect the change in the liquid's pressure to the diaphragm, which deforms at high pressure. The higher-pressure deformation is converted into an electrical signal using a strain gauge. We use a simplified Bernoulli equation to convert pressure into a level: P = ρgh.潜水式压力传感器安装在容器底部。它们检测液体对膜片压力的变化，膜片在高压下会发生变形。高压下的这种变形通过应变计转换成电信号。我们使用简化的伯努利方程将压力转换为液位：P = ρgh。潜水式压力传感器安装在容器底部。它们检测液体对膜片压力的变化，膜片在高压下会发生变形。高压下的这种变形通过应变计转换成电信号。我们使用简化的伯努利方程将压力转换为液位：P = ρgh。

● Radar Level Transmitters● 雷达液位变送器

Radar-level sensors detect level changes using microwaves with a frequency of 6.8 GHz for shorter ranges (under 30m) and 26 GHz for longer ranges (over 30m, up to 70m). The choice of frequency can also vary depending on the manufacturer's implementation. However, in principle, they all work by transmitting microwaves that reflect from the liquid surface to the receiver. The time taken by the microwave represents the distance between the detector transmitter and the liquid surface. They offer an accuracy of ±3mm.雷达液位传感器使用频率为 6.8GHz 的微波来检测较短距离（30 米以内）的液位变化，使用频率为 26GHz 的微波来检测较长距离（30 米以上，最高可达 70 米）的液位变化。具体频率的选择也可能因制造商的实现方式而有所不同。不过，从原理上讲，它们都是通过发射微波，微波从液面反射回接收器来工作的。微波所用的时间代表了探测器发射器与液面之间的距离。它们的精度为±3 毫米。

● Ultrasonic Level Sensors● 超声波液位传感器

The working mechanism of the ultrasonic level sensor is similar to that of radar-level transmitters. It uses sound waves with a frequency between 20 and 200 kHz, higher than the human hearing capability. The sensor and transmitter are installed on top of the container. It emits the sound that reflects from the surface, and the time taken for the sound to emit and return to the sensor represents a level similar to radar-type transmitters. The accuracy of the ultrasonic level sensor is 0.5% – 1% of full scale, or ±3mm (whichever is larger).超声波液位传感器的工作原理与雷达液位变送器类似。它使用频率在 20 至 200 千赫兹之间的声波，高于人类的听力范围。传感器和变送器安装在容器顶部。它发出的声波从液面反射回来，声波发出和返回传感器所用的时间代表液位，类似于雷达型变送器。超声波液位传感器的精度为满量程的 0.5% - 1%，或±3 毫米（取较大值）。

● Capacitance Level Sensors● 电容式液位传感器

The capacitance-based level sensor uses two electrodes that are inserted into the liquid. The length of the level sensor electrodes is equal to the length of the container. It uses a container as one electrode, while the other is mounted on the sensor. As the container level rises, the capacitance between the electrodes changes. It allows the measurement of granular, liquid, or powder material. The accuracy is around 1%FS.基于电容的液位传感器使用两个插入液体中的电极。液位传感器电极的长度与容器的长度相等。它将容器作为其中一个电极，而另一个则安装在传感器上。随着容器液位的上升，电极之间的电容会发生变化。它能够测量颗粒状、液态或粉状的物料。其精度约为 1%FS。

5. Industrial Applications of Level Sensors5. 液位传感器的工业应用

Level sensors are used in numerous industrial applications. Without them, industrial process automation is incomplete. Managing liquid levels is critical in industries to allow chemical reactions, manage mixtures, maintain inventory, ensure cooling, and many other applications.液位传感器在众多工业应用中被使用。没有它们，工业过程自动化就不完整。在各行业中，管理液位至关重要，这有助于化学反应、混合物管理、库存维护、冷却保障以及许多其他应用。

● Water Treatment and Management● 水处理与管理

In water treatment and management, the quantity of liquid is managed through level sensors. Any addition of a liquid to form a mixture during the treatment process requires careful management of liquid inventories. Sedimentation tanks that separate sand from water or, in the case of reservoirs, maintain water levels as per requirements are all applications within the water treatment and management systems.在水处理和管理中，液位传感器用于管理液体的量。在处理过程中，任何添加液体以形成混合物的操作都需要对液体库存进行仔细管理。沉淀池用于将沙子从水中分离出来，或者在水库的情况下，根据需要维持水位，这些都是水处理和管理系统中的应用。

● Chemical Processing Industries● 化学加工工业

The chemical processing industry uses level sensors to monitor the levels of chemical tanks and pressure vessels. These sensors must tolerate environments with varying pH levels and chemical properties. Non-contact level sensors are ideal for chemical tanks, which can be corrosive or hazardous.化工加工行业使用液位传感器来监测化学储罐和压力容器的液位。这些传感器必须能够耐受不同 pH 值和化学性质的环境。非接触式液位传感器非常适合用于可能具有腐蚀性或危险性的化学储罐。

● Food and Beverage Manufacturing● 食品和饮料制造业

Various liquids can be mixed in food and beverage manufacturing. Level sensors, which provide accurate quantity measurements for dairy, brewery, or beverage production, are typically used. However, the sensor needs to be certified for food safety. Depending on the region, certifications from the FDA, 3-A Sanitary standards, EHEDG, NSF, or WRAS may be required.在食品和饮料生产中，各种液体可以混合在一起。用于乳制品、啤酒厂或饮料生产的液位传感器能够提供精确的量度测量，通常会被采用。然而，该传感器需要获得食品安全认证。根据所在地区，可能需要获得美国食品药品监督管理局（FDA）、3-A 卫生标准、欧洲卫生设备设计组织（EHEDG）、美国国家卫生基金会（NSF）或英国水研究协会（WRAS）的认证。

● Oil and Gas Industry ● 石油和天然气行业

The process starts by extracting liquid or gas from the earth, which requires storage, purification, separation, transportation, and storage. During each of the processes, the industrialist is carefully monitoring the levels. A gas can be liquid when pressurized, while crude oil separation requires careful evaluation of levels. Monitoring levels are essential regardless of the part of the oil and gas process that occurs. In this case, the material can be hazardous or flammable. Therefore, using sensors at a compatible level with ATEX IECEx certification is preferable. Radar, ultrasonic, and float switch level sensors are standard in the oil and gas industry.该过程始于从地下抽取液体或气体，这需要进行储存、净化、分离、运输和储存。在每个过程中，工业人员都会仔细监测液位。气体在加压时可以变成液体，而原油分离则需要仔细评估液位。无论在石油和天然气过程的哪个环节，监测液位都是至关重要的。在这种情况下，材料可能是危险或易燃的。因此，使用与 ATEX IECEx 认证兼容等级的传感器是更可取的。雷达、超声波和浮球开关液位传感器在石油和天然气行业中是标准配置。

● Agricultural Irrigation Systems● 农业灌溉系统

In agriculture and irrigation systems, radar and ultrasonic level sensors are popular. This non-contact nature allows them to handle food-grade material without directly coming in contact. In agriculture, monitoring levels of silos, powders, feed, grain, and pellets in tanks are an essential part. Similarly, monitoring the water level of canals through radar sensors proves vital for the industry. Modern sensors combined with advanced PLCs allow users to monitor their levels remotely.在农业和灌溉系统中，雷达和超声波液位传感器很受欢迎。这种非接触式的特点使它们能够处理食品级材料而不直接接触。在农业领域，监测筒仓、粉末、饲料、谷物和颗粒在储罐中的液位是必不可少的一部分。同样，通过雷达传感器监测渠道的水位对行业来说至关重要。现代传感器与先进的可编程逻辑控制器（PLC）相结合，使用户能够远程监控其液位。

6. Benefits of Implementing Level Sensors in Industrial Processes6. 在工业流程中采用液位传感器的优势

As we can see, level sensors provide extensive benefits with their wide-scale applicability in industrial processes. Here are some of the key benefits:正如我们所见，液位传感器因其在工业流程中的广泛应用而提供了诸多益处。以下是其中一些关键优势：

✔ Enhanced Operational Safety✔ 提升运营安全

Level sensors provide safety in cases that require handling flammable liquid or hazardous material for the environment. They help monitor and maintain the level, thus avoiding spillover potential and preventing accidents such as explosions or flames.液位传感器在需要处理易燃液体或对环境有害的材料的情况下能提供安全保障。它们有助于监测和维持液位，从而避免溢出的可能性，并防止诸如爆炸或起火之类的事故。

✔ Improved Process Efficiency✔ 提高流程效率

Ensuring that the tank or flow path levels are within operational range keeps the process efficient. Preventing tank shortages will keep the process running smoothly without any breaks or stoppages in production. Automation through the level sensors with feedback control eliminates the need for personnel intervention, which can cause a slower response.确保储罐或流道液位处于运行范围内，可使工艺流程保持高效。防止储罐缺液可使工艺流程平稳运行，不会出现任何中断或停产情况。通过液位传感器实现自动化并采用反馈控制，可消除人工干预的需要，人工干预可能会导致反应迟缓。

✔ Cost Reduction through Automation通过自动化实现成本降低

The cost of labor drastically reduces with the use of level sensors. Sluggish human intervention can cause process delays, eventually reducing costs. Overall process costs come down through inventory control, waste production, and time reduction.使用液位传感器可大幅降低人工成本。人为干预迟缓会导致流程延误，最终降低成本。通过库存控制、减少废品产生以及缩短时间，整体流程成本得以降低。

✔ Real-Time Monitoring Capabilities✔ 实时监控功能

Level sensors that use sound waves to measure the water level offer extremely low response times. It can take data in milliseconds (ms) time intervals and provide real-time monitoring and control capabilities. They operate 24/7 without the need for any breaks or changes.利用声波测量水位的液位传感器响应时间极短。它可以在毫秒（ms）的时间间隔内采集数据，并提供实时监测和控制能力。它们可以全天候运行，无需任何停机或更换。

Conclusion 结论

Overall, level sensors are vital to industrialization. They provide automation, efficient operation, and increased output. Industrialists can utilize various levels of sensors to produce fast and effective results. They can use subversive pressure transducers, radar transmitters, ultrasonic, or capacitance-based level sensors. A single industry may utilize all these types for its process. Manufacturers of level sensors now provide enhanced accuracy, precision, protection, compatibility, range, and output, depending on the application.总体而言，液位传感器对于工业化至关重要。它们能够实现自动化、高效运行以及提高产量。工业从业者可以利用不同类型的液位传感器来获得快速且有效的结果。他们可以使用颠覆性的压力变送器、雷达发射器、超声波或基于电容的液位传感器。一个行业可能会在其生产过程中使用所有这些类型的传感器。如今，液位传感器的制造商根据应用的不同，提供了更高的精度、准确性、防护性、兼容性、量程和输出。总体而言，液位传感器对于工业化至关重要。它们能够实现自动化、高效运行以及提高产量。工业从业者可以利用不同类型的液位传感器来获得快速且有效的结果。他们可以使用颠覆性的压力变送器、雷达发射器、超声波或基于电容的液位传感器。一个行业可能会在其生产过程中使用所有这些类型的传感器。如今，液位传感器的制造商根据应用的不同，提供了更高的精度、准确性、防护性、兼容性、量程和输出。

If you are looking for high-end sensors for your industry, consider Rika sensors. They are efficient, widely compatible, reliable, and highly safe for operations. Their aur submersible liquid level transmitter (RKL-01), with a stainless steel diaphragm and broad temperature compatibility, is also a radar level transmitter (RKL-02) for non-contact measurement. The capacitance-based fuel level sensor (RKL-04) provides a coaxial capacitor design and high health and safety standards. Visit the Rika level sensor page for all the details!如果您正在为您的行业寻找高端传感器，不妨考虑瑞卡传感器。它们高效、兼容性广、可靠且操作安全性高。其 aur 潜水式液位变送器（RKL-01）采用不锈钢膜片，具有广泛的温度兼容性，同时还有雷达液位变送器（RKL-02），用于非接触式测量。基于电容的燃油液位传感器（RKL-04）采用同轴电容设计，并符合高健康和安全标准。访问瑞卡液位传感器页面获取所有详细信息！