Infrared Refrigerant Leak Sensor (NDIR) — PPM Early Warning & %LEL Safety
Winsen® infrared (NDIR) refrigerant leak sensors provide stable, selective measurement for A1, A2L, and A3 gases—R134a, R410A, R32, R454B, R1234yf/ze, R290, R600a. Choose ppm-level accuracy for early warning, or %LFL/%LEL for safety interlocks. Seamless BMS/PLC integration via 4–20 mA, RS-485 Modbus, and relay outputs.
Why Infrared (NDIR) for Refrigerant Leak Detection?
High Selectivity
NDIR measures gas absorption at specific IR wavelengths, delivering excellent selectivity for HFC/HFO refrigerants and robust A2L/A3 options.
Stability & Low Drift
Dual-channel optical design with reference beam minimizes temperature/ageing drift, extending calibration intervals (often 12–24 months).
Not O₂-Dependent
Infrared sensing does not require oxygen, unlike catalytic beads—ideal for machinery rooms, cold rooms, and enclosed HVAC spaces.
Model Guide — Select by Class & Measurement
Infrared (NDIR) refrigerant leak sensors and detectors for A1, A2L, and A3 gases: R32, R454B, R1234yf/ze, R134a, R410A, R290, R600a. PPM early warning & %LEL safety, 4–20 mA, RS-485 Modbus, relay outputs. OEM/ODM by Winsen® for bulk orders.
NDIR Refrigerant Sensor
Semiconductor Refrigerant Sensor
How Infrared (NDIR) Refrigerant Sensors Work
| Stage | What Happens | Benefit |
|---|---|---|
| Emission | IR source emits broadband light through the gas sample. | Reliable optical excitation |
| Filtering | Narrowband optical filter targets refrigerant absorption bands; a second channel serves as reference. | Gas selectivity & drift compensation |
| Detection | Photodetectors measure attenuated signal vs. reference; MCU computes concentration. | Stable ppm / %LEL output |
| Compensation | Temperature/pressure & baseline routines (e.g., ABC optional) correct drift. | Long intervals between calibrations |
Typical Applications
VRF/VRV indoor units & hotel rooms
Mount low (~150–300 mm AFF) near indoor units and pooling points; link alarms to fan shutdown and fresh-air purge.
Chiller & machinery rooms, compressor racks
Place near compressors, separators, valves, and low spots/sumps; use IP-rated housings and BMS interlocks.
Cold storage & refrigerated display cases
Install beneath cases and along manifolds/pipe runs; choose condensation-resistant designs and curtain/exhaust interlocks.
Data center in-row/CRAC units
Position in return air, under raised floors, and near coils; ppm early warning protects personnel and uptime.
Heat pumps & general HVAC
For A2L/A3, use %LFL tiers (e.g., ~25% pre-alarm; ~50% main) to trigger ventilation and equipment shutdown.
Infrared vs. Other Technologies
| Technology | Best For | Range | Advantages | Considerations |
|---|---|---|---|---|
| NDIR (Infrared) | A1 ppm; A2L ppm/%LEL; A3 %LEL (IR-LEL) | ppm → %LEL | High selectivity, low drift, not O₂-dependent | Higher initial cost; protect from heavy condensation/dust |
| MOS (Semiconductor) | A2L/A3 %LEL | 0–100% LEL | Fast response; cost-effective | Cross-sensitivities; periodic calibration |
| Catalytic Bead | General hydrocarbons (A3) | 0–100% LEL | Mature tech | Needs O₂; can be poisoned (silicones/lead) |
Placement & Setpoints — Good Practice
- Mounting height: Most refrigerants are heavier than air ⇒ mount low; confirm with airflow studies.
- Coverage: Approx. 5–10 m radius per sensor in open rooms; add units near valves/joints and low pockets.
- Alarm tiers: A2L/A3: pre-alarm ≈25% LFL; main ≈50% LFL. A1: ppm bands (e.g., 1,000–5,000 ppm) per spec.
- Interlocks: Pre-alarm → ventilation; Main → equipment shutdown + beacons/BMS alarm.
Finalize thresholds and quantities against your project specification and local codes.
Why Global Clients Choose Us?
The company consistently adheres to the quality policy of “Fine Craftsmanship, Scientific Innovation, Pursuit of Excellence, and Value-Added Service.” By formulating production process control plans and work instructions, it has established a standardized, accountable, and regulated process management system. Additionally, the company has independently developed an MES production management system, enabling comprehensive and visual management across the entire workflow.
30+ YEARS OF EXPERIENCE
R&D, manufacture and sales of sensors and sensing solutions.
QUALITY GUARANTEE CONTINOUS IMPROVEMENT
Complete and rigid process flow control, coupled with significant improvements.
INTERNATIONAL MARKET
Deliver sensing products to more than 100 countries and regions.
STABLE SUPPLY CHAIN RELIABLE PRODUCTION
Core components not subject to constraints, advanced equipments for manufaturing and test.
R&D STRENGTH TECHNOLOGY INNOVATION
200+ patents, 180+ R&D team members, self-built labs for continous innovation.
ONE-STOP SERVICE
Professional consultation, fast delivery, 24 hours after-sales support.
Leading the Industry, Innovative & Controllable Technology
With robust R&D capabilities, we maintain sustained input in R&D and unwavering commitment to technological innovation. This not only ensures that we remain at the forefront of industry but also drives continuous innovation, leading the future trend of the sensing industry.
FAQs — Infrared (NDIR) Refrigerant Leak Sensors
Is NDIR better than MOS for refrigerants?
For ppm early warning and long-term stability, NDIR is typically preferred. For %LEL safety trips on A2L/A3 gases, NDIR-LEL or MOS can both be used depending on budget and environment.
How often do NDIR sensors need calibration?
12–24 months is common with periodic bump tests. High-dust or high-humidity sites may require more frequent checks and filter maintenance.
Where should the sensor be installed?
Near likely leak sources (compressors, valves, joints) and low-lying accumulation points; avoid strong supply air that could bypass the sensor.
Do Winsen IR sensors integrate with BMS/PLC?
Yes—native 4–20 mA, RS-485 Modbus RTU, and relay contacts make integration straightforward.
Can you customize for OEM programs?
Absolutely. We customize ranges, firmware, connectors, harnesses, housings, and branding for volume deployments.
