Nexisense Pyroelectric Sensor | High-Reliability Module, Empowering Industrial-Grade Infrared Perception System Integration

In the fields of industrial IoT, smart buildings, environmental safety, and process control, precise capture of infrared radiation has become a key perception link. The Nexisense pyroelectric sensor series takes the pyroelectric effect as the core, combined with precision optical filtering and signal processing technology, to provide B-end system integrators with full-spectrum solutions from passive human detection to active NDIR gas analysis. This series of modules emphasizes high consistency, low false alarm rate, wide temperature adaptability, and interface compatibility, helping projects achieve reliable long-term operation and large-scale deployment.

Engineering Principle of Pyroelectric Effect and Differential Suppression Mechanism

Pyroelectric sensors are based on the physical property that pyroelectric materials (such as lithium tantalate or modified PZT) generate surface charges when temperature changes, enabling passive detection of dynamic infrared radiation. Unlike thermopiles for static temperature measurement, pyroelectric responds only to dT/dt, i.e., transient changes in infrared flux.

The typical structure adopts dual-element or quad-element complementary design: two sensitive elements are configured back-to-back, outputting differential signals. Stationary heat sources (such as equipment shells, sunlit objects) cause both elements to receive the same radiation, resulting in signal cancellation; moving or flickering heat sources (such as human crossing, flame pulsation) sequentially illuminate different areas, generating significant differential mode voltage, which is processed by built-in JFET or operational amplifier and then output.

To expand the detection field of view and improve directional resolution, Fresnel lenses are usually paired to divide the field of view into multiple alternating sensitive zones and dead zones, further enhancing response to dynamic targets while suppressing environmental background interference.

Multi-Scenario Applications and System Integration Value

Through filter selection and circuit optimization, Nexisense pyroelectric sensors derive three major engineering-grade application directions to meet different project requirements for detection distance, response time, and selectivity.

Passive Infrared Human/Motion Detection (PIR Mode)

Suitable for security, building automation, and energy efficiency management. The module is highly sensitive to human radiation in the 8–14μm band (peak around 9.5–10μm), with typical detection distance up to 10–15m (depending on lens design), response time<1s.

Integration Value:

• Smart lighting and HVAC linkage: based on zone occupancy detection, achieve on-demand ventilation and lighting control, meeting LEED/WELL certification requirements.

• Intrusion detection and perimeter security: combined with video analysis systems, provide low-power supplementary trigger source, reducing overall system standby power consumption.

• People flow statistics and behavior analysis: multi-sensor array deployment, achieving coarse-grained counting and trajectory tracking without privacy images.

Flame Detection and High-Temperature Warning

For hydrocarbon flame radiation in the 4.3–4.5μm CO/CO₂ emission band and high-frequency flicker (1–20Hz) characteristics, equipped with narrowband filter (typical CWL 4.35μm, HBW 150–200nm), effectively suppressing sunlight, incandescent lamps, and blackbody background interference.

Integration Value:

• Industrial warehousing and oil/gas facilities: early flame identification, response time<5s, supporting relay or Modbus output linked to fire linkage.

• Electric vehicle/energy storage system safety: monitoring flame or high-temperature radiation caused by battery thermal runaway, supporting redundant multi-point deployment.

• Forest and open area monitoring: wide-angle lens configuration, achieving large-range passive fire source inspection.

NDIR Gas Concentration Analysis

Utilizing target gas molecular vibration-rotation absorption lines (such as CO₂@4.26μm, CH₄@3.31μm), combined with reference channel to achieve dual-wavelength differential measurement, compensating for light source drift and ambient temperature influence.

Integration Value:

• Petrochemical and mine safety: combustible gas leak monitoring, detection limit ppm level, supporting explosion-proof enclosure packaging.

• Indoor environment and agricultural control: real-time CO₂ concentration feedback, linked to fresh air/ventilation systems; livestock ammonia/CH₄ monitoring.

• Process analysis instruments: integrated into multi-gas analyzers, providing UART/RS485 output, convenient for SCADA or PLC access.

Selection Guide: Key Parameters for Matching Project Specifications

To ensure seamless module-system adaptation, it is recommended to evaluate from the following dimensions:

Power supply design recommends stable 5V/3.3V supply, add LDO and decoupling capacitors to suppress noise.

System Integration Notes and Best Practices

• Optical window protection: Avoid dust/oil deposition, recommend adding lens protective cover or regular cleaning.

• Anti-interference optimization: Keep away from RF sources and strong electromagnetic fields; differential output lines use shielded twisted pair, good grounding.

• Signal processing: Recommend digital filtering algorithms (such as moving average + threshold comparison) to suppress transient noise; flame detection requires frequency analysis module to confirm flicker characteristics.

• Installation orientation: Lens facing target area, avoid direct sunlight or heat sources; gas NDIR needs to ensure gas chamber airflow unobstructed, no condensation.

• Long-term calibration: Regular zero/span calibration, NDIR channel recommends reference channel self-calibration.

OEM Customization and Bulk Supply Support

Nexisense provides flexible customization services for B2B projects, including:

• Filter band/bandwidth adjustment, channel number expansion.

• Output protocol modification (Modbus RTU, custom frame format).

• Shell packaging (TO-5/TO-39, explosion-proof type), brand labeling.

• Factory batch calibration and traceability, reliability accelerated life testing.

• Long-term framework agreement, buffer inventory and fast delivery mechanism.

These measures help integrators reduce secondary development costs, accelerate project implementation and market response.

Frequently Asked Questions

 1.What is the main difference between pyroelectric sensors and thermal imagers in engineering applications?    

Pyroelectric is low-cost passive single-point/multi-zone detection, suitable for dynamic change detection; thermal imaging provides two-dimensional temperature distribution, but high power consumption and high cost, suitable for precision diagnosis rather than large-scale triggering.

2. How to effectively reduce the false alarm rate of flame detection? 

Through narrowband filter to filter background radiation, combined with signal flicker frequency analysis (1–20Hz bandpass filter) and multi-sensor fusion confirmation, typical false alarm rate can be controlled below 1%.

3. What is the role of the reference channel in NDIR gas detection? 

The reference channel monitors non-absorption band light intensity, compensating for light source aging, temperature drift, and dust contamination, achieving long-term zero drift <±2%FS/year.

4. How is the module's electromagnetic interference resistance ensured?

Internal metal shielding packaging, output lines support differential transmission; system-level recommends signal line shielding, power filtering, and good grounding, compliant with IEC 61000-4-3/6 standards.

5. PIR module performance in high humidity or low temperature environments? 

Operating range -40–+85℃, 0–95%RH (non-condensing), humidity affecting lens condensation can be mitigated by heating modules or anti-fog coatings.

6. What key data does the UART output protocol support? 

Typically includes concentration/status value, raw ADC reading, fault code, and checksum, supports configurable baud rate 9600–115200bps, convenient for embedded integration.

7. What customization development options are supported? 

Filter specifications, number of sensitive elements, output interface type, overall dimensions, protocol extension, EMC optimization, and batch consistency calibration, etc.

8. How to maintain detection accuracy during long-term operation? 

Regular zero-point calibration (clean air/nitrogen environment), NDIR recommends span calibration every 6–12 months; built-in self-diagnostic function can report optical window contamination or element degradation in real time.

Conclusion: Partner with Nexisense to Build a Reliable Infrared Perception System

The Nexisense pyroelectric sensor series, with mature pyroelectric technology, precision optical design, and engineering-grade reliability, provides a solid perception foundation for security, fire protection, environmental monitoring, and industrial process control. It helps system integrators simplify development processes, enhance system robustness, and support large-scale deployment needs.

Welcome industrial system integrators, solution providers, and project engineering parties to contact the Nexisense team for detailed specification sheets, sample evaluation, or customization scheme discussions. We are committed to becoming your stable partner in the field of infrared perception, jointly promoting innovative applications of smart safety and environmental management.