Catalytic Bead Gas Sensor:Working,Advantages,disadvantages,Manufacturers

Introduction : Catalytic Bead Gas Sensor, often called a pellistor sensor, is one of the most widely used technologies for detecting combustible gases such as methane, propane, butane, and hydrogen. Based on the principle of catalytic oxidation, the sensor contains a small heated bead coated with a catalyst. Because of their proven performance and simplicity, catalytic bead gas sensors have been a trusted solution in oil and gas facilities, chemical plants, mining operations, and industrial safety systems for decades.

Catalytic Bead Sensor Working principle

It works based on principle of catalytic oxidation. It is used to detect combustible gases like methane, propane, hydrogen etc. The sensor has two tiny beads viz. active and reference bead. Let us understand its working.

• When methane gas contacts the active bead, it oxidizes on the catalyst surface.
• This reaction releases heat and increases resistance of the bead.
• The wheatstone bridge circuit used in this sensor measures difference in resistance between active and reference beads.
• The output signal of the sensor is proportional to the gas concentration.

Advantages of Catalytic Bead Sensor

Following are some of the benefits of Catalytic Bead Sensor.

1. It supports wide detection range.
2. It offers fast response time.
3. It is lower in cost and simple in design.
4. It is based on well established technology used since decades.
5. It is rugged and reliable in harsh environments.

Disadvantages of Catalytic Bead Sensor

Following are some of the drawbacks of Catalytic Bead Sensor.

1. It requires oxygen to function.
2. It is susceptible to catalyst poisoning.
3. It requires frequent calibration for consistent performance.
4. It consume more power than IR sensors.
5. It is subjected to cross sensitivity from many gases including methane.
6. It’s life time is about 2-5 years.

Manufacturers

Conclusion: They are valued for their fast response time, ability to detect a wide range of gases, and cost effectiveness, though they require periodic calibration and are less suitable for oxygen deficient or catalyst poisoned environments.