SemeaTech 4-Series NO2-20 Electrochemical Sensor
Electrochemical nitrogen dioxide sensor for OEM gas-monitoring instrumentation and fixed or portable equipment integration.
Manufacturer: SemeaTech
Technical Specifications
| Measurement | NO₂ (electrochemical) |
|---|---|
| Nominal range | 0–20 ppm |
| Maximum overload | 250 ppm |
| Typical T90 | ≤30 s |
| Resolution | 0.008 ppm |
| Sensitivity | −0.60 ± 0.15 µA/ppm |
| Operating temperature | −40 to 50°C |
Official Technical Source
4-Series NO₂-20 — negative response polarity and SO₂ interference — original maker engineering data
Measured range, current output and lifecycle apply to the specified SemeaTech model rather than the whole sensor family.
| Attribute | Original manufacturer data | Application significance |
|---|---|---|
| Gas and technology | Electrochemical nitrogen dioxide, 0–20 ppm | Distinct from ozone, NO and sulfur dioxide cartridges. |
| Overload / polarity | Maximum overload 250 ppm; sensitivity −0.60 ±0.15 µA/ppm at 20 °C | Negative sensor current is expected and requires correct analogue polarity. |
| Response and resolution | T90 ≤30 s, resolution 0.008 ppm | Do not claim resolution is the total accuracy of field detector. |
| Zero / calibration | 0 mV nominal bias; ±0.4 µA zero max; baseline shift <0.5 ppm over −40 to +50 °C | Electronics should handle offset/negative current correctly. |
| Cross-gas effect | 5 ppm SO₂ produces approximately −5 ppm NO₂-equivalent signal; 1 ppm Cl₂ produces ~0.6 ppm | Negative cross-sensitivity may mask true NO₂ concentration. |
| Operating environment | −40 to +50 °C, 15–90%RH noncondensing | Field humidity/temperature compensation may require host system. |
| Expected life | 2 years in clean air; recommended storage 10–30 °C | Keep replacement and bump-test records. |
Integration, cross-sensitivity and maintenance
A negative electrochemical sensitivity sign is intrinsic to this NO₂ cell output and must not be interpreted as a negative gas concentration. The manufacturer’s published cross-sensitivity table suggests co-present SO₂ could create a negative NO₂-equivalent offset. In traffic/industrial applications compare toxic gas mixtures and consider separate ozone or SO₂ channels where required. A 4-Series physically similar cartridge is not an automatic pin-and-calibration replacement for H₂S or CO. The complete alarm remains subject to separate functional and Ex approval testing.
Primary SemeaTech source: Original product model information and technical sheets. Confirm current exact part code, supply revision and regional certification before an approved installation.
AirAlign independent editorial analysis · 25 October 2026. OEM sensor data do not grant completed gas instrument certification.