Gas sensor

A passive chemiresistive gas sensor in a standard SMD footprint — detecting hydrogen and other reducing gases without a heater. Designed from the ground up for distributed deployment at scale.

Form factor	1206 SMD — 3.2 × 1.6 mm. Mounts on standard or flex PCB.
Power	Resistive read in milliseconds. Multiple parallel sensors, small battery, years of operation.
Sensing principle	Passive chemiresistive — no heater required
Target gases	H₂, CO, alcohol vapor, spoilage gases, and other reducing gases
H₂ range	~500 ppm to 3% — well below the 4% lower explosive limit
Response	Seconds-scale. Strong signal to presence and concentration change.
Temperature	−15°C to 60°C
Humidity	Long term operation demonstrated <75 % RH. Condensation requires mitigation; integration approaches are under validation.
Lifetime	Years expected, condition-dependent. No significant drift observed over 12+ months in ongoing testing.
Substrate	Standard FR-4, Kapton flex, ceramic
Manufacturing	PCB-panel process — low-cost, high-volume pathway
Calibration	High signal, low part-to-part variation — no individual calibration required
Interface	Simple resistive

What to expect

Strong indicative signals

Highly sensitive to H₂ below 4%, with a reliable, repeatable response to gas presence and concentration changes. In unheated operation, the nonlinear response limits concentration accuracy. The strong signal supports fast, simple alarm thresholds without complex signal conversion. Not a certified safety instrument.

Responds to multiple gases

Responds to H₂, CO, alcohols and other reducing gases. Useful where the expected gas is known, or where an indication of any of several target gases is valuable.

Cannot distinguish between gases

The sensor responds to reducing gases but cannot identify which specific gas is present.

Coverage between sensing points

Sensor blankets and strips fill gaps between certified point safety sensors, covering areas with multiple sensing locations. They show where gas appears and spreads and help localize leaks across equipment with many potential sources. Explore sensing array applications.

Flex substrate — conforms to complex surfaces

NSI’s 1206-size sensors mount directly on Kapton flex PCB, allowing arrays to conform to pipes and complex surfaces. A thin profile (1–3 mm) fits into narrow gaps, slots, enclosures and other tight spaces. Small housings protect individual sensors in use. Sensor spacing and measurement electronics can be adapted to the application.

Kapton flex sensor strip wrapped around a pipe — 8-sensor Kapton flex strip wrapped around a pipe.

Kapton flex sensor blanket wrapped around a pipe — 16-location sensing blanket wrapped around a pipe.

Sensor Arrays Datasheet

Pilot projects & custom systems

Bring distributed sensing to your equipment.

Try NSI sensor blankets and strips in a pilot project, or work with us on a custom sensing system. Sensor layout, housings and measurement electronics can be adapted to your gas sensing requirements, equipment and operating environment.

Discuss a pilot project →