Interference Magnitude
Interfering chemical species or environmental variables generate unwanted responses in physical and chemical transducers. An inherent cross sensitivity causes a gas sensor to produce a signal output in the presence of non-target compounds. The metric governs sensor accuracy in complex gas mixtures, establishing the error boundary where false positive readings occur.
This effect applies specifically to target analyte detection limits and stops applying when interfering species are completely scrubbed from the sample stream. Quantitative evaluation relies on exposing the sensor to known concentrations of interfering gases alongside target species under controlled laboratory conditions.
Selectivity Ratio
Transducer selectivity defines the ratio of target gas response to interfering gas response. High cross sensitivity to ambient humidity or volatile organic compounds degrades target analyte measurement accuracy. Sensor manufacturers publish selectivity matrices detailing interference coefficients for common industrial gases.
Temperature Influence
Environmental thermal variations alter the reaction kinetics of secondary chemical species on sensor surfaces. Elevated temperatures increase cross sensitivity toward non-target hydrocarbons in electrochemical and metal oxide sensors. Precise thermal stabilization reduces secondary reaction rates.
Compensation Scheme
Multi-sensor arrays and digital filtering algorithms mitigate cross sensitivity errors in field instruments. Matrix inversion calculations process signals from complementary sensors to isolate target gas concentrations. Physical scrubbing filters placed upstream of the sensor head remove interfering compounds before contact with the active element.
