What is a Gas Sensor, and How does it Work? — An IoT Revolution
Gas sensors are ready to transform the way IoT-based industries function. By enabling higher security for the industry, gas sensors ensure freedom from gas leaks and improve safety for the workers. Learn more about IoT gas sensors in the blog below and why they are necessary for your industry.
With Industry 4.0 gaining popularity, IoT has now become highly prevalent in different industry verticals. IoT enables manufacturers to optimize their workflows and achieve productive results for their industries. In addition, adopting IoT also significantly promotes the security of industries. IoT systems rely on various sensors to ensure proper safety in an industrial setup.
Some of the sensors include temperature sensors, proximity sensors, pressure sensors, gas sensors, and more. Though each sensor has its own role, the gas sensor is the most crucial of all. A gas sensor is used to sense the presence and measure the amount of gas spread in an industry.
It helps industries build a safe and reliable process and ensure the complete security of people working in industries from gas exposure and leaks. Let's learn more about gas sensors!
What is a Gas Sensor?
A gas sensor is a device that detects the presence of various gases in the surrounding environment.
Gas sensors are used in various IoT applications to:
Carbon monoxide, nitrogen dioxide, methane, etc. are a few gases that a gas sensor can detect.
Comprehending the Architecture of a Gas Sensor
Though there are a variety of gas sensors available for the IoT industries, the most common one to be used is a metal oxide semiconductor-based gas sensor. Let us understand this gas sensor and its architecture.
A gas sensor generally has five layers in its architecture:
- Gas Sensing Layer: This is the primary layer of the gas sensor and is responsible for sensing the variation in the concentration of the gases in an industrial atmosphere. Based on the concentration of gases present in the surroundings, this layer changes its electrical resistance and switches its resistance value.
- Heating Coil: This is another vital component of a gas sensor, made of nickel-chromium and having a high melting point. The purpose of this coil is to burn in the sensing element and increase its temperature and efficiency.
- Electrode Line: These are platinum lines embedded inside the gas sensor that help detect gas leakage by producing small currents in the circuit when gas is detected. The electrode line is connected to an electrode that allows the current to pass.
- Electrode: It is a component of a gas sensor that acts as a junction between the sensing layer and the electrode line. Usually, the electrode is made of gold.
- Tubular Ceramic: It is an aluminum oxide-made component present between the gas sensing layer and the heater coil. The tubular ceramic helps maintain the preheat conditions of the gas sensor to generate effective and optimal results.
How Does a Gas Sensor Work?
A gas sensor, especially one made of a metal oxide semiconductor, has quite simple functioning and working procedures. It uses paramagnetic gas properties to detect gases in the environment.
The gas sensor leverages a chemiresistor to conduct current and detect a gas leak. Generally, Tin Dioxide (SnO2) is the most commonly used chemiresistor in this process as it is an n-type semiconductor with several free electrons.
The oxygen in the atmosphere attracts the free electrons in SnO2 and pushes them to the surface of SnO2. This leads to the presence of no free electrons, and the electrode line in the gas sensor generates zero output current.
In the case of a gas leak, the SnO2 gas reacts with the adsorbed oxygen and breaks the bond between free electrons and oxygen. This releases the electrons to flow freely in the surroundings and generate current, which helps detect a gas leak.
Here is a table showcasing different types of gas sensors and their operating principles:
What are the Types of Gas Sensors?
There are several types of gas sensors used for a variety of purposes. Here are some of the most common gas sensors:
Metal Oxide-based Gas Sensors
It is one of the most commonly used gas sensors in IoT industries. Metal oxide sensors work by changing the resistance of the detecting layer in response to the presence of harmful gases.
Metal Oxide-based sensors can detect leakage of gases like carbon monoxide, hydrogen, oxygen, nitrogen dioxide, alcohols, hydrocarbons, and volatile organic compounds (VOCs).
Electrochemical Gas Sensor
This type of gas sensor uses an electrochemical reaction to detect and measure the presence of gases in a given environment. The sensors utilize a substance, such as an electrolyte, to initiate a chemical reaction that produces an electrical current and helps detect a gas.
Electrochemical sensors are used for a variety of applications, such as
Acoustic-based Gas Sensor
These sensors use the acoustic properties of the gas to detect its presence. They measure the speed of sound and its frequency in the gas to determine its composition and presence in the atmosphere.
Acoustic-based gas sensors are used to detect a wide range of gases, including methane, carbon dioxide, and other hazardous gases.
Capacitance-based Gas Sensor
It is a type of gas sensor that detects gases by measuring the capacitive effect of the gas molecules on a capacitor. This type of sensor is used for a wide range of applications, from monitoring air quality in homes and offices to detecting pollutants in industrial environments.
Optical Gas Sensor
The optical gas sensors use optical spectroscopy to detect the presence of specific gases in an environment. They measure the concentration of gases by analyzing the light absorption of a particular gas in a sample. Optical gas sensors can detect a wide range of gases, including hydrocarbons, nitrous oxide, carbon dioxide, and ammonia.
Calorimetric Gas Sensor
It is a gas sensor that primarily works on the principle of calorimetry, which is the science of measuring heat. The sensor measures the heat transfer rate between the gas being measured and the sensor itself.
This heat transfer rate is then used to detect the presence of gases in the atmosphere. Calorimetric gas sensors usually detect gases like carbon monoxide, sulfur dioxide, nitrogen dioxide, ammonia, and hydrocarbons.
Use Cases of Gas Sensors in IoT
IoT gas sensors are extremely beneficial in building safe and reliable industrial processes. Here are some of the uses of gas sensors in an IoT industrial setup:
- They are used to monitor the concentration of toxic gases in the industrial atmosphere.
- IoT sensors are used for air quality checks in industries and offices.
- They are used to monitor the CO2 levels in a particular environment.
- IoT sensors can be used to detect fire.
Conclusion: The Role of Gas Sensors in the IoT Revolution
Gas sensors play a significant role in the IoT revolution by allowing for the monitoring of dangerous gases such as carbon monoxide and methane. These sensors can be connected to the IoT network, enabling real-time notifications when dangerous levels are detected, allowing immediate action to be taken, and preventing any potential hazards. Get in touch with our IoT teams to learn more or discuss your project requirements.
