Everything You Need to Know about IoT Sensors

Discover what IoT sensors are, how they work, their real-world applications and benefits, and how these smart devices shape our future.

person accessing a storage by using a sensor with a mobile on hand

What are IoT Sensors?

Internet of Things or IoT sensors are specialized electronic devices that sense, detect, and measure various parameters in our physical environment. This small device is usually embedded into or attached to machines and gadgets, gathering salient information (e.g., temperature, light, motion, and sound) that informs decision-making, driving relevant personnel to appropriate and immediate action.

Mechanics of the IoT Infrastructure

The sensor, often referred to as the eyes and ears of the IoT ecosystem, works best when connected with other essential components. Here is a quick breakdown of the whole infrastructure:

  • The sensor is the chief element of the infrastructure. It could target physical properties like smoke detectors and pressure transducers or have multiple applications like RFIDs and QR codes. 
  • Microcontrollers process and manage the data collected by the sensor, often performing tasks like filtering and calibration. 
  • The communication module transmits the data to devices (e.g., desktop computers, laptops, or tablets) or the cloud. Examples of these include satellite, WiFi, or Bluetooth. 
  • Most IoT systems have a user interface that converts the information for consumption. It could be a live monitoring display or a notification when pre-set limits are reached. 

Individuals working in industries that rely on these IoT sensors and accompanying systems should be well-versed in how it works, as the knowledge helps in efficient troubleshooting, tailor-fitting solutions, and ensuring data accuracy. 

Importance and Uses

Today, there are over 15 billion IoT devices powering various industries all over the world. And with its numerous considerable benefits, it is doubtful that the reliance on these smart gadgets will wane. 

  • Collects data instantaneously – The sensor’s main task is to gather real-time data, enabling organizations to make better decisions regarding their operations. Smart cities like New York, London, and Singapore install various devices, like intelligent traffic lights to manage traffic conditions, AQMs (Air Quality Monitors) to measure air quality, and CCTVs to increase public safety. 
  • Increases control over conditions – In the past, operational disruptions were difficult to manage because it took quite a while before the relevant personnel were notified about it. Since these tools alert users in crises, mitigating actions are taken immediately. This is especially true in healthcare where IoMT (Internet of Medical Things) can monitor patients’ conditions remotely and alert the staff in emergencies.
  • Enhances proactive approach to work – IoT sensors inform operators about the physical condition and output of their machinery, facilitating predictive maintenance. This is particularly helpful for the manufacturing and construction sectors, as their tasks are highly dependent on functional equipment.
  • Minimizes errors and miscalculations – Precision and accuracy go hand in hand with automated environmental monitoring and measuring. Problems caused by the slightest fluctuation in temperature or humidity – especially in the agricultural sector and the rest of the supply chain – can be dealt with immediately, ensuring optimized operations and high-quality end products.  
  • Improves safety – The world is filled with hazards, ranging from chemical leaks to home intruders. Installing security cameras on your property or proximity detectors near highly energized areas in the factory does not just protect people from physical harm but also elevates their well-being and boosts their confidence to accomplish anything that they need to do. 

Types of IoT Sensors

The multitude of IoT sensors existing today is a response to the specific demands of diverse industries. As aforementioned, some of these tools are applicable in various sectors, such as motion detectors and electromagnetic readers. However, most are optimized for specific tasks. Here are some of the most common:

Thermal Sensors 

As the term implies, this device determines and measures the temperature in a space or of a particular object. It is one of the most common types of sensors in IoT, used across industries primarily as a preventive mechanism. Listed below are the different kinds of thermosensors:

  • Negative Temperature Coefficient (NTC) Thermistors are the most widely used and found in refrigerators, air conditioners, room thermometers, kettles, irons, and even smartphones. 
  • RTD (Resistive Temperature Detector), often installed in engines, detects the temperature of oils and air intake. 
  • Thermocouples Temperature Probes are frequently employed in the food and beverage industry. IoT sensor examples include hot plate monitoring and oven control.
  • Semiconductor-based sensors are installed in numerous electronics, including smartphones, laptops, and CPUs. 

Humidity Sensor 

This device measures the amount of water vapor in the air. It is usually installed with temperature implements since relative humidity depends on air temperature. Here are some of its most common applications:

  • All HVAC (heating, vents, and air conditioning) systems, from laundry dryers to fax machines, have this particular sensor. 
  • Weather stations use the hygrometer to determine the likelihood of fog, rain, and other weather conditions.
  • In the food processing sector, this instrument ensures that food items are within ideal humidity to prevent spoilage.

Whether you’re in the food manufacturing sector or the medical field, give the remote temperature and humidity monitoring system a try to get precise temperature readings around the clock, get notifications when temperatures go beyond the pre-set ranges, and quickly act when issues emerge.

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Also known as optical sensors, these devices respond to light and measure its waves at various points in the spectrum and are extensively used in the following:

  • Light fixtures, such as street lamps, that automatically turn on when it gets dark
  • Computers and copy machines
  • In the medical industry, it is used in photoplethysmography for monitoring heart rate, contactless dispensers, and breath analyzers. 
  • Bar and some QR (Quick Response) codes require a beam of light for scanning. 


Motion detectors, powered by light beams, microwaves, and ultrasonic waves, sense physical movement in a defined space, particularly when something blocks or interrupts the energy flow. Integrated into security systems, these include control cameras, faucets, doors, gates, and many more. 

Proximity Sensors

Although this uses roughly the same technology as motion detectors, this instrument detects the presence of an object within a pre-set distance. IoT sensor examples include elevators, rail tracks, parking lots, and assembly lines in the manufacturing sector.

Pressure Indicators

This device gauges the force, whether liquid or gas, exerted on the sensor in a specific area. Pressure sensors are utilized extensively in automobile, aircraft, and machine maintenance or repair. It also plays a significant role in meteorology, sensing air pressure that could signal the approach of a hurricane or typhoon.  

Level Sensors 

These monitor and translate the level of any substance (solid, liquid, or gas) relative to a predefined value into an identifiable signal. The simplest illustration would be a car’s gas gauge, which lights up when the fuel drops to its lowest level.

Quality Sensors

These detect the presence of a substance that may have leaked from their enclosed containers into another space. The sensor is helpful in laboratories where hazardous chemicals are used or even in homes when a specific gas (e.g., carbon dioxide or liquefied petroleum gas) is diffusing in a room. 


Also known as image sensors, these capture images that will be digitally stored and processed. Specific IoT sensors examples include the following:

  • License plate readers
  • Facial recognition systems
  • Digital cameras on mobile devices


Also known as acoustic sensors, these track and identify sound signals, including voice, snaps, knocks, and claps. Both conventional devices like radios and phones, as well as more modern applications in security and home automation systems, utilize these sensors.


Radiofrequency identification (RFID), as the name implies, utilizes radio waves to transmit signals that activate the tag. The most commonly used sensor for security and authentication, RFIDs track and identify objects, living or not.  

Current Challenges and Future Advancements 

The IoT has grown in the past two decades and has since played a significant role in how people live, interact, and conduct business. But it also has brought new difficulties to those who rely on these. And as the infrastructure grows more widespread and available, these challenges are more pronounced. 

  • Miniaturization to reduce power consumption – Since many IoT devices operate on batteries that tend to lose power fast, frequently replacing batteries is a must. And that is quite costly. Miniaturization or making the components of the device more compact will consume less energy. It is easier to integrate smaller tools into various equipment and, according to some, make the gadget more long-lasting.
  • Edge computing and AI solve interoperability – At times, a single machinery requires several types of sensors (e.g., coolant thermostat, exhaust oxygen sensor, and ignition crankshaft in an engine control unit or ECU), which hinders seamless integration and data exchange. AI, machine learning, and edge computing reduce this problem and identify anomalies in real time.
  • Wireless sensor networks enhance scalability – Managing several devices is incredibly complex, requiring stable network performance and efficient data management. LoRaWan and other low-power, long-range communication maintain connections between the IoT device and the network, ensuring reliability even when workloads and the number of users increase. 
  • Blockchain integration improves data security and privacySecurity and privacy, critical concerns in the IoT infrastructure, are often under attack and vulnerable to unauthorized access, damage, and theft. Aside from implementing robust measures like encryption and firewalls, integrating a decentralized and tamper-resistant ledger ensures data integrity.
Eunice Arcilla Caburao
Article by
Eunice Arcilla Caburao
Eunice is a content contributor for SafetyCulture. A registered nurse, theater stage manager, Ultimate Frisbee athlete, and mother, Eunice has written a multitude of topics for over a decade now.