OX-A431 Ozone and Nitrogen Dioxide Sensor
O3 / NO2 Gas Sensor, Electrochemical, A-Series, ppb-level oxidising monitoring
Combined O3 / NO2 oxidising gas sensor for high performance air-quality networks
The OX-A431 is a 4-electrode oxidising gas sensor that measures the combined concentration of ozone (O3) and nitrogen dioxide (NO2) at ppb levels. Designed for environmental air quality and fence-line applications, it offers best-in-class baseline stability and fast response. When paired with a filtered NO2 sensor such as NO2-A43F, it enables accurate separation of O3 and NO2 channels via algorithmic subtraction. OX-A431 is ideal for fixed AQ networks, roadside monitors and high-performance research instruments.
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Key Specifications:
|
Sensor Model |
Target Gas |
Technology / Package |
Concentration Range |
Typical Sensitivity (O3 / NO2) |
T90 Response Time |
Operating Life |
|
OX-A431 |
Ozone (O3) / Nitrogen Dioxide (NO2) |
Electrochemical, A-Series, 4-electrode |
0 – 20 ppm O3 |
O3: –200 to –650 nA / ppm at 1 ppm |
< 80 s (typical) |
> 24 months (24 - month warranted) |
|
Feature |
Benefit |
|
Combined O3 + NO2 oxidising channel |
Reduces sensor count in multi-pollutant AQ monitors while preserving ppb-level performance. |
|
PPB-level resolution with low noise |
Supports urban background, roadside and research-grade AQ measurements. |
|
Compatible with NO2-A43F differential approach |
Enables algorithmic separation of O3 and NO2 for dual-channel reporting. |
|
A-Series 4-pin footprint |
Simplifies design reuse with other A-Series ppb sensors (CO-A4F, H2S-A41, NO-A41, NO2-A43F). |
|
OX-A431+ IST variant |
On-board memory and temperature sensing provide plug-and-play replacement and integrated compensation. |
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Technical Datasheet
Application Notes
- O3 / NO2 AQ use cases and sensor pairing with NO2-A43F in Alphasense Air Quality Product Guide
Design Considerations
- Use with Analogue Front End boards (AFE) for ppb-level environmental networks.
- Combine with filtered NO2 sensors for differential O3 calculation; ensure both channels are zero and temperature corrected before subtraction.
Safety Document
- Guidance on oxidising toxic gas handling and fixed system design in Alphasense Gas Safety Product Guide
Related Products
- Accessories / Boards:
- AFE – Analogue Front End Boards
- Foam Seal
- Dust Filter
- Gas Hoods
- Frequently Bought Together:
- NO2-A43F filtered NO2 sensor to separate O3 from NO2 measurements
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