Imagine a future where you never have to endure long lines at airport security, wait for hours to see a doctor, or be stuck in traffic jams, ever again. Thanks to the Internet of Things (IoT), such a future will be here sooner than you think and at the heart of this transformation are IoT sensors and actuators.

Internet of Things (IoT) sensors are components of IoT devices that measure physical quantities, converting them into data that can be interpreted by humans or machines. The data gathered by IoT sensors enables various types of control and automation.

From measuring greenhouse gas emissions as part of the fight against climate change, and monitoring crop health to promote sustainable agriculture, to powering smart supply chains that reduce waste, there are numerous possible applications of IoT sensors. Dgtl Infra provides a comprehensive overview of the landscape of IoT sensors and actuators, including the various types, manufacturers, and their use cases.

What are IoT Sensors?

IoT sensors are components of IoT devices that are used to measure aspects of the physical world, like temperature, humidity, and motion. Data from IoT sensors can be used to gain insights, improve decision-making, optimize processes, and automate tasks, across varied industries and use cases.

Essentially, any sensor that is connected to the internet, or to an IoT device, is an IoT sensor. This means that there are as many types of IoT sensors as there are quantities or attributes of things to measure or detect in the world.

Classification of IoT Sensors

IoT sensors can be categorized in a number of ways, including:

  • Type of Physical Quantity Measured: sound, light, temperature, electromagnetic radiation, acceleration, velocity, and color, are just a few examples of IoT sensor types based on what they measure
  • Energy Usage: based on whether or not they need an external power source, IoT sensors are classed as active or passive sensors, respectively. IoT-enabled radio-frequency identification (RFID) readers are examples of passive sensors that are also wireless IoT sensors
  • Method of Measurement: IoT sensors use different mechanisms of measurement, and can be categorized accordingly into electrical sensors, optical sensors, chemical sensors, and gyroscopic sensors
  • Accuracy: in terms of range of measurement, IoT sensors can be classed as high- and low-precision sensors. High-precision IoT sensors are typically used in controlled environments, and can measure very small changes, while low-precision sensors can only measure large changes, but are often used in harsh and extreme environments
  • Output Type: based on the type of output they produce, IoT sensors can be categorized as analog or digital sensors. Analog sensors have a continuously variable output – for example, an electrical voltage that varies continuously with temperature. While digital sensors have a discrete output – for example, pulse code modulation (PCM) sensors

Examples of IoT Sensor Data Use Cases

Examples of the applications of data gathered from IoT sensors include:

  • Home or Industrial Automation: data from IoT sensors powers automation everywhere, from programming lights, fans, and air conditioning to run only when they are really needed, to enabling factories to save time and resources by monitoring their machinery
  • Research and Development (R&D): IoT sensors are already being used to support research and development (R&D) efforts, such as testing new technologies or learning about ecosystems and wildlife
  • Marketing and Customer Service: in retail, IoT sensors can gather data on customer behavior and preferences, such as where people look, walk, pause, and buy, which can then be used to tailor marketing efforts and improve customer service
  • Healthcare and Environment: from monitoring air and water quality, to tracking patient health remotely, IoT sensors allow for faster and better decision-making for public health and the environment

Types of IoT Sensors

Examples of the most widely used types IoT sensors are flow sensors, force sensors, humidity sensors, pressure sensors, photoelectric sensors, water level sensors, and ultrasonic sensors.

Flow Sensors

IoT flow sensors, also called IoT flow meters, are used to measure the rate of flow of a fluid. Many technologies are used in flow meters, with magnetic, ultrasonic, vortex, and turbine flow sensors being a few of the different measurement methods. Furthermore, each technology type has pros and cons, and the best sensor technology for a given application depends on the requirements of that context.

READ MORE: Internet of Things (IoT) Technology – Quick and Easy Guide

Applications of IoT flow sensors include:

  • Industrial Processes: IoT flow sensors can be used to automate industrial processes, such as chemical production, oil & gas refining, and food and beverage processing
  • Water Treatment and Distribution: by measuring and controlling the flow of water, IoT flow sensors help to prevent leaks and increase efficiency in water treatment and distribution systems, for domestic, industrial, and agricultural use
  • Energy Management: IoT flow meters are being used in oil and natural gas pipelines for energy management and to prevent dangerous leaks or equipment failures
  • Environmental Monitoring: by monitoring the flow of water in rivers, streams, and wetlands, IoT flow sensors help to improve environmental management and support flood warning systems

IFM, OMRON, TSI, and Emerson are examples of prominent manufacturers of flow sensors for Internet of Things (IoT) applications.

Force Sensors

Force sensors, also known as load cells, have a wide range of IoT and Industrial Internet of Things (IIoT) applications. Specifically, force sensors can take the form of compression-, tension-, shear load-, single-point-, and S-type load cells.

Typically, force sensors convert mechanical force into an electrical signal, which technically makes them transducers – devices that convert one form of energy into another. Applications of IoT force sensors include:

  • Material Handling: IoT force sensors can be used to monitor the weight of materials being moved or stored in warehouses, distribution centers, and other facilities. These sensors enable the automation of manufacturing and supply chain processes
  • Structural Monitoring: by continuously monitoring and logging the stresses, strains, and shear forces experienced by bridges, buildings, and aircraft, IoT force sensors improve safety and allow for preventative maintenance before failures occur
  • Environmental Monitoring: IoT force sensors help to monitor environmental conditions, such as soil and water quantities. This improves the quality of research and intervention in the areas of climate change and drought monitoring

Mettler Toledo, Honeywell, and TE Connectivity are examples of leading manufacturers of force sensors for Internet of Things (IoT) devices.

Humidity Sensors

Humidity sensors, also called hygrometers, are devices that are used to measure and monitor the moisture content in the air. These sensors include capacitive, resistive, and infrared measurement methods. Typically, humidity sensors provide an output in the form of an electrical signal, which can, in turn, be used to control other devices or systems.

In the context of IoT, humidity sensors allow for real-time monitoring and control of humidity. This can help to optimize processes, improve efficiency, and reduce waste. Below are a few specific examples of use cases for IoT humidity sensors:

  • Home and Office Automation: IoT humidity sensors help monitor the humidity of the air in buildings, enabling the automation of air conditioning and HVAC systems. Also, these sensors have important implications on improving the energy efficiency of buildings
  • Weather Forecasting and Climate Research: IoT humidity sensors permit continuous, real-time measurements of localized atmospheric humidity levels. By using this data, weather forecasters can make predictions with a level of accuracy that would otherwise be impossible. Moreover, tracking changes in humidity levels over time is also important to improve our understanding of climate change
  • Industrial Process Control: in manufacturing, warehousing, and storage, changes in humidity can have major effects on product quality, durability, and shelf life. IoT humidity sensors allow superior control and monitoring of these processes, improving efficiency and sustainability

Vaisala, Michell Instruments, Fisher Scientific, and Comet are examples of well-known manufacturers of humidity sensors for Internet of Things (IoT) applications.

Pressure Sensors

IoT pressure sensors measure the application of force by gasses or liquids. They work by using force balance, piezoelectric, capacitive, or resistive principles to measure the pressure being applied to a surface. Similar to force sensors, many pressure sensors are often (but not always) transducers – devices that convert one form of energy into another.

Many of the use cases are similar to the examples listed under humidity sensors, as pressure and humidity are often closely-related environmental factors, and are commonly monitored by several systems. Applications of IoT pressure sensors include industrial process control, building automation, environmental monitoring, transportation, medical devices, and wearable devices.

READ MORE: Internet of Things (IoT) Devices – What’s Smart in 2023?

Ashcroft, Rockwell Automation, and HYDAC are examples of the leading manufacturers of pressure sensors for IoT and Industrial Internet of Things (IIoT).

Photoelectric Sensors

Photoelectric sensors, also called photoelectric switches or proximity sensors, use a light to detect the presence or absence of an object, or to assess other physical properties such as air clarity. Typically, these devices use a light source such as LEDs or lasers, aimed at a sensor. Any interruption in the beam is detected and used to perform various measurements.

Photoelectric sensors are widely used in IoT applications owing to their accuracy, reliability, and resistance to interference. For instance:

  • Industrial Automation: IoT photoelectric sensors are used to detect the presence of objects on conveyor belts, assembly lines, and other industrial automation systems
  • Smart Cities: smart city systems use IoT photoelectric sensors to monitor traffic, detect pedestrians and bicycles, and improve public safety
  • Security: in security systems, IoT photoelectric sensors help detect intruders and physical security breaches

READ MORE: Internet of Things (IoT) Security – Next-Generation Protection

Pepperl+Fuchs, Siemens, and Festo are examples of the leading manufacturers of photoelectric sensors for Internet of Things (IoT) applications.

Water Level Sensors

IoT water level sensors measure the amount of water in a water body or storage tank. These devices commonly use float switches, ultrasonic sensors, optical sensors, or pressure sensors to measure or infer the amount of water present.

IoT water level sensors have myriad applications, such as:

  • Agriculture: IoT water level sensors monitor the level of water in irrigation ponds, canals, or reservoirs, optimizing irrigation and helping to reduce wastage and leaks
  • Manufacturing: in industrial processes, the level of water in tanks is monitored by these sensors, enabling sophisticated automation for the production of chemicals, pharmaceuticals, and other products
  • Temperature Control: IoT water level sensors are used to monitor the level of water in humidifiers, chillers, and refrigeration and HVAC systems. This is useful in residential as well as healthcare and warehousing / storage contexts

Endress+Hauser, IFM, and SST Sensing are examples of the leading manufacturers of water level sensors for Internet of Things (IoT) applications.

READ MORE: Internet of Things (IoT) Examples by Industry in 2023

Ultrasonic Sensors

While most of the other sensors discussed above were categorized based on the physical quantity measured, ultrasonic sensors are based on the method of measurement. IoT ultrasonic sensors use high-frequency sound waves to measure distance or detect the presence or absence of objects.

These devices generate ultrasonic pulses and measure the reflected or “bounced-back” signals of those pulses to calculate distance or the presence of an object. Being non-invasive, relatively inexpensive, and resilient enough to work in diverse environments, ultrasonic sensors have a wide range of IoT applications, including level sensing (as mentioned above), proximity sensing, flow rate measurement, positioning and navigation, industrial automation, and medical applications.

Omega, Wenglor, and TDK Electronics are examples of the prominent manufacturers of ultrasonic sensors for IoT and Industrial Internet of Things (IIoT) applications.

What are IoT Actuators?

IoT sensors play the important role of capturing data, but to be truly useful, these sensors need to be connected to actuators, which are components that can take physical actions based on the input from the sensors. Actuators convert energy into mechanical motion and come in different types, like electric motors, solenoids, pneumatic and hydraulic cylinders, and piezoelectric actuators.

Example use cases of IoT actuators include:

  • Remote Management of Energy Infrastructure: from adjusting the flow of oil and natural gas in pipelines, and controlling pumps at reservoirs and substations, to changing the angle of solar panels or windmill blades, IoT actuators help with energy management by enabling motors, drives, switches and other mechanisms to be controlled remotely
  • Automation in Agriculture: IoT actuators enable the automation of irrigation systems and other agricultural equipment. By opening or closing valves – whether automatically, based on the input from IoT sensors, or manually based on inputs from an operator in a control room – IoT actuators help control the flow of water across farms for optimal crop growth
  • Industrial Automation: based on inputs from IoT sensors such as vision, optical, or ultrasonic sensors (among others), IoT actuators can move robotic arms to automate production lines in manufacturing facilities

ABB, Schneider Electric, Sumida, and KEMET are examples of the most established manufacturers of actuators for Internet of Things (IoT) applications.

Adam Simmons covers Towers for Dgtl Infra, including American Tower (NYSE: AMT), Crown Castle (NYSE: CCI), SBA Communications (NASDAQ: SBAC), Cellnex Telecom (BME: CLNX), Vantage Towers (ETR: VTWR), IHS Holding (NYSE: IHS), and many more. Within Towers, Adam focuses on the sub-sectors of ground-based cell towers, rooftop sites, broadcast / radio towers, and 5G. Adam has over 7 years of experience in research and writing for Towers.


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