Sensors play an important role in human life can be used for environmental sensing, thermal sensing, voice sensing, and pressure sensing, etc. By sensors, Let’s explore what are active sensors and passive sensors and what are the differences between them.

Usage: We can gather different measurements and observations from a distance.

Read also: Active Hub and Passive Hub Difference

  • Many organizations like forest controls use sensors for harsh environmental situations.
  • For network temperature monitoring for server temperatures.
active an passive sensors
example of forest controls

Active Sensor:

An active sensor that senses and responds to some type of resistance/input from the physical environment. This sensor doesn’t need an external source of power to operate the device.

Usage of Active Sensors: Nowadays they are used widely for manufacturing purposes or near networking devices etc. Sensors are usually used to monitor and gather information on industrial machines. server areas and data centers are also monitored by those sensors so anomalies can be detected and repaired.

Examples of Active Sensors:

1. Thermocouples –

Thermocouples are called sensors. Made of two different metals with two output wires.
Whenever there is a temperature difference between these two junctions a voltage is produced in times of millivolts.

Applications: Used to sense or measure the temperature on the server for alarming situations.

thermocouples active sensor example
Thermocouples

2. Solar cell:

Whenever light falls on the cell it generates voltage, also called photovoltaic. So we can call it an active sensor.

solar cell as active sensor photovoltaic cell
solar cell

3. Piezo Electric Sensor

A piezoelectric sensor is called an active sensor. The working is, when pressure is applied to the plates a voltage is developed. It can be used to measure the vibrations.

What is piezoelectric sensor active
Piezoelectric

4. Mic is another active sensor example.


Passive Sensors:

Passive sensors are different from the active ones they need an external power supply or excitation to make it respond.

Likewise in electronics, we supply voltage at two terminals and they signal something from the output terminal.

Examples of Passive Sensor

1. Potentiometer:

We supply a voltage to its two terminals and it and another terminal we get the output it is the best example of a passive sensor.

potetiometer passive sensor example
Potentiometer

2. Load cell:

Used in weighting scales, we will apply the voltage we will get output from it depending on the load or force on it.

what is load cell sensor
load cell

3. Hall Effect sensor:

To detect the magnetic field in it we can measure the current.

hall effect sensor passive sensor
Hall effect sensor

4. Capacity Microphone:


Active and Passive Sensors Difference

Active SensorsPassive Sensors
Active sensors don’t need a powersource to output a voltage or signal.Active sensors don’t need a power source to output a voltage or signal.
Active sensors produce electric voltage or current in response to the environmental change/stimulation.Passive sensors need some source or voltage to respond.
Active sensors don’t need a power resource of power to output a voltage or signal.Examples are a Potentiometer, Load cell, Hall effect sensor, Capacity microphone, etc.
Active sensors don’t need a power ourcesource of power to output a voltage or signal.Passive sensors require a power source to output some signal or voltage.

Questions and Answers of Difference in Active and Passive Sensors

What is remote sensing and why do active sensors play and important role?

In remote sensing, an active sensor transmits and sends out a signal or wavelength(light) or electrons to be bounced off a target. Moreover, the sensor gathers the data by sensing and sends its reflection to inform.