On-board leak detection for fuel-cell vehicles
Automotive Hydrogen Leak Detector
Catalytic combustion · 0–40,000 ppm · PWM to the ECU
Hydrogen circuit
Overview
A compact hydrogen detector for leak monitoring on fuel-cell vehicles. The granular electroplated sensing element gives a fast response, high resistance to poisoning and a long service life; the PWM output drops straight into the vehicle ECU without a separate conditioning module.
Key features
- Start-up time under 1 second, T80 response under 2 seconds
- High resistance to HMDSO / D5 poisoning
- Service life over 20,000 operating hours
- Built-in temperature compensation
- PWM output at 250 Hz — H₂ (ppm) = 500 × (Duty % − 10)
- Catalytic combustion — no electrolyte
Specification
Technical data
Core performance parameters
| Item | Specification |
|---|---|
| Detection gas | Hydrogen (H₂) |
| Detection range | 0 – 40,000 ppm (0 – 4.0 vol% in air) |
| Initial accuracy | ± 10 % over 10,000 – 40,000 ppm |
| Power supply | DC 9 – 16 V (nominal 12 V), 1 W |
| Output signal | PWM, 250 Hz — H₂ (ppm) = 500 × (Duty % − 10) |
| Housing material | PBT + PC-(GF + GS) 40 — marking FH2-HY04-GS2 |
| Cross-sensitivity | No interference from 5,000 ppm HC, CO, DME or alcohol |
Operating and environmental ratings
| Item | Rating |
|---|---|
| Operating temperature | −35 °C to +85 °C, < 95 %RH non-condensing |
| Storage temperature | −40 °C to +105 °C, < 95 %RH non-condensing |
| Physical dimension | 62.2 (W) × 49.0 (D) × 22.5 (H) mm |
| Weight | 58 ± 2 g |
| Connector | 4-pin automotive — Sumitomo Wiring Systems 6189-1231 |
| Long-term stability | Verified over 19,000+ h continuous operation |
Mount with the sensor opening facing down — calibration is done in this attitude. Never apply high-pressure air or liquid directly to the PTFE membrane.
Application
Where it is used
Detection element: Pt wire 30 μm + Pd; reference element: Pt + SiO₂
More in hydrogen circuit
Related reading
From the engineering notes
Background on the design decisions behind this component — all articles.
What a fuel cell stack expects from its balance of plant
A stack presents four interfaces — hydrogen, air, coolant and DC bus. Match each one with the right parts and integration gets much simpler.
Automotive Hydrogen Leak Detector — product brochure (PDF)
Full specifications, model selection tables and engineering notes. Two pages, English.
Download PDF
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