Dynamic Range

  The range of signals that can be reliably transmitted in a device, usually a digital system. Digitizing electronics are often carefully designed for the desired dynamic range to fit into the information range given by the device. Thus an analogue-to-digital converter (ADC) trying to record with acceptable resolution light pulses from minimum ionizing tracks and from energetic showers in a calorimeter, will necessarily need a large information range (usually given as a word length, e.g. 10 or more bits); often, the effective range of an ADC range is extended by giving it a non-linear response: this extends the dynamic range, preserving all relevant information, but for adding, the information has to be translated back to a linear scale. For non-linear response, the error given by the least count (viz. the smallest step by which digitized signals can be different) does not translate into a constant absolute error. The dynamic range is sometimes given as the ratio between the highest and lowest signal, and may then be expressed in decibels (i.e. the tenfold of this ratio).