Catalytic Bead vs Infrared
Side by side comparison: how they work, where each fits, and which to choose.
Quick answer: Catalytic detectors sense almost all flammable gases including hydrogen but need oxygen and can be poisoned; infrared detectors cannot be poisoned and work without oxygen, but miss hydrogen.
Catalytic Bead vs Infrared: Comparison Table
| Aspect | Catalytic Bead | Infrared |
|---|---|---|
| Principle | Heat from burning gas on a hot bead | Infrared absorption |
| Hydrogen | Yes | No |
| Needs oxygen | Yes | No |
| Poisoning | Silicones, sulfur, lead can poison | Immune |
| Fail safe | Bead failure can go unnoticed | Optics self check |
| Maintenance | More frequent calibration | Longer intervals |
Choose Catalytic Bead when
- Hydrogen and mixed flammable gases
Choose Infrared when
- Hydrocarbon gases offshore and in process units
Key Differences Explained
Infrared point and open path detectors dominate hydrocarbon detection today. Catalytic detectors remain essential for hydrogen and some solvents.
Both are calibrated in % LEL with a certified span gas.
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Frequently Asked Questions
What is the difference between Catalytic Bead and Infrared?
Catalytic detectors sense almost all flammable gases including hydrogen but need oxygen and can be poisoned; infrared detectors cannot be poisoned and work without oxygen, but miss hydrogen.
Why can catalytic detectors read low?
Poisoning or inhibition by contaminants, or low oxygen.
Can IR detect all hydrocarbons equally?
Response varies by gas; detectors are calibrated for a target gas.
What detects hydrogen without catalytic beads?
Electrochemical, thermal conductivity or semiconductor sensors.
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