Measurement Disturbance
Unwanted response generated by co-existing alcohols in the ambient environment alters the accuracy of electrochemical and semiconductor gas sensors. This ethanol interference causes the instrument to register a false positive concentration of the target gas because the hydroxyl functional group behaves similarly to other reducing gases on the active sensor surface. The resulting deviation impairs the reliability of environmental monitoring and industrial safety systems.
Sensor Susceptibility
Most tin dioxide sensors operate at elevated temperatures where many volatile compounds undergo oxidation, so that ethanol interference occurs whenever solvent vapours or cleaning agents are present. The sensor cannot distinguish the current change produced by ethanol from the current change produced by methane or carbon monoxide. This lack of selectivity is particularly problematic in industrial storage areas where sanitising chemicals are frequently deployed.
Calibration Drift
Sourcing requirements for industrial safety monitors establish strict tolerances for cross-sensitivity, usually defined as the apparent concentration of target gas produced by a specific exposure to ethanol. When this threshold is exceeded, the calibration of the primary sensor becomes invalid, necessitating immediate field correction or sensor replacement. Instrument technicians verify these tolerance levels by applying a certified reference gas containing a precise concentration of the interfering alcohol and observing the sensor response.
Mitigation Method
Physical filter media are positioned ahead of the sensing chamber to eliminate the unwanted alcohol molecules. In critical applications, dual-wavelength infrared sensors are selected because their optical absorption bands avoid the characteristic frequencies of ethanol.
