Fiber optic commutation encoders are sometimes called ‘explosion proof’ and are used in applications where methane, propane, or other highly combustible gases are present. The AMT31 and AMT33 are not recommended for explosion-proof applications but can withstand similar environmental factors. Finally, capacitive encoders generate output code by detecting changes in capacitance using a high frequency, reference signal. The capacitive style are low cost, high resolution encoders and are perfectly suited for high precision applications.