Fiber optic encoders generate code using a laser and phototransistor and are typically high cost, high resolution devices. They are used in explosion-proof applications where extremely flammable gasses are present. Finally, capacitive encoders generate output code through detecting changes in capacitance using a high frequency, reference signal. Same Sky's AMT capacitive encoders are high accuracy devices that are rugged and able to operate in a wide range of temperatures and other extreme environments.