Gas Sensors: Gas Detection and Leak Detection Explained

This page covers gas sensors, also known as gas detection sensors. These sensors are crucial for detecting gas leaks. We’ll also touch on gas sensor manufacturers and vendors.

Semiconductor-based gas detection sensors have been widely used for years, particularly in the automotive industry. With increased usage of cooking gas in homes and petrol/diesel vehicles, it’s become essential to detect gases like methane and carbon monoxide. Gas sensors fulfill this need by detecting potential gas leaks. They are often installed with associated electronic circuits in factories, kitchens, workshops, and even smoke detectors.

The semiconductor material within the sensor is sensitive to changes in gas concentrations. It can detect as little as 50 to 100 ppm of carbon monoxide or other gases.

Gas Sensor Internals and Operation

Figure 1 illustrates the internal components of a gas sensor. It consists of a semiconductor material surrounding a filament heater, all housed within a stainless steel body.

The front portion is cup-shaped, allowing gas to flow and reach the sensitive material, typically Tin Oxide. This material is doped with an n-type semiconductor.

Let’s delve into the operation or working principle of a gas sensor:

1. Heating: The filament heater heats the chemical material.
2. Resistance Change: The resistance of this material decreases in the presence of vapors. These vapors pass through a mesh and reach the tin oxide.
3. Detection: Gases such as hydrogen, carbon monoxide, alcohol, and other combustible gases cause a decrease in the resistance of the tin oxide semiconductor. This change in resistance is the key principle used in gas sensor design.

Gas Sensor Manufacturers and Vendors

Here are some manufacturers and vendors of gas sensors:

• Futurlec: Develops various gas sensor types, including carbon dioxide (CO2) sensors, alcohol sensors, LPG sensors, and carbon monoxide sensors.
• FIGARO Engineering inc.
• ThomasNet.com
• DIGIKEY
• Parallax Inc.
• Honeywell Analytics
• Emerson Electric Co.