How are the measurement range and accuracy of a gas detector determined?

The measurement range refers to the concentration span the instrument can detect and must cover the minimum and maximum concentrations possible in the environment. For instance, the range for combustible gases is typically 0-100% LEL (Lower Explosive Limit), while for toxic gases like carbon monoxide, it might be 0-1000 ppm. Accuracy refers to the deviation between the measured value and the true value, usually expressed as a percentage of Full Scale (%FS), such as ±2% FS. Selection should be based on the sensitivity required by the application scenario; safety alarm scenarios may require higher accuracy.