Sensors are developed to address specific physical conditions and produce a signal (usually electric) that can represent the magnitude of the conditions under surveillance. These conditions could be light, heat, sound, distance, pressure, or some other situation which is more specific, such as the presence or absence of gas or liquid.

Types of IoT sensors 

Temperature Sensor

It is one of the most basic types of sensors and is used in all kinds of IoT applications where it is vital to keep track of the thermal conditions of air, work environment, machines etc.

One of the primary roles of these sensors in the manufacturing industry is to control the temperature. Likewise, these sensor systems are also used in the agriculture sector for tacking the temperature of plant, soil or water.

Temperature sensor includes a thermistor, thermocouple, integrated circuits (ICs) and resistor temperature detector (RTDs).

Smoke Sensor

These devices are used in different applications such as in residences, industries or in commercial buildings. The rise of the IoTs makes these devices very simple and easy to use. Additional features can also be used to improve security by adding a wireless connection to smoke detectors.

Humidity Sensors

Humidity sensors are used to measure the humidity level of the water vapour in the air. Otherwise, it will impact human comfort and multiple industrialised processes. Humidity can be measured as Relative humidity, Absolute humidity, and Specific humidity.

Pressure Sensor

A pressure sensor is an instrument fitted with a pressure-sensitive feature that is used against a silicon or stainless steel diaphragm for gas or liquid pressure measurements. It then transforms the calculated value as the output into an electrical signal. It is also used to calculate the flow of water through tube or tank and to alert the person concerned when something needs to be fixed. Such sensors are also tailored to the estimation of altitude and force for aircraft and smart vehicles.

Gas Sensor

Gas sensors are used mainly for toxic gas detection. Photo-ionization, semiconductor and electrochemical technologies are the most widely used. Different types of gas sensors are available based on technical requirements and advances to extend wired and wireless communication in IoT applications.       
            

Infrared (IR) Sensors

Infrared sensors are used mainly for measuring heat from objects. Such devices are used in various IoT applications such as healthcare for the control of blood flow or blood pressure (BP). Apart from this, these sensors are used for monitoring smartphones, wearable light detection devices or blind spot detection in cars.

Accelerometer Sensor

The accelerometer sensor can be used to measure the force exerted on the object. They are mostly used in aircraft vehicles or in smartphones. Similarly, they are used to identify object directions, tilt, tap, shake, position and motion, vibration, or shock in different applications. Accelerometers types include capacitive, Hall-effect and piezoelectric.

Proximity Sensors

Proximity sensors are used to identify a surrounding object that has no physical contact or does not exist. Such sensors are categorised into different types, such as capacitive, inductive, ultrasonic, magnetic, and photoelectric. These sensors are often used for the monitoring, control and countering of objects processes.

Gyroscope Sensors

The angular speed and angular rate of an object are measured by gyroscope sensors. In particular, it is used for the measurement and analysing of angular and rotational velocity speed of an object in 3D plane. They can predominantly be used in many different types of vehicle navigation systems, mobile devices, helicopters and drones.

Ultrasonic Sensors

The distance between the two objects by means of sound waves is determined with an ultrasonic sensor. An ultrasonic sensor uses a transducer to send and receive ultrasonic pulses which relay back information on the proximity of the object.