timeequivalent

Timeequivalent, or time-equivalent, is a cross-disciplinary term used to describe expressing a quantity in terms of a duration or in terms of a duration under a given rate. It is not a standard technical unit, but a descriptive concept that helps compare different quantities by translating them into time-based measures. The exact meaning depends on the context and the rate or reference used for the conversion.

In physics and engineering, the idea often appears when a quantity is related to time through a rate. For example, energy E consumed at a constant power P over a period t is E = P t. Here, given E and P, one can compute a time t = E / P, making energy have a time-equivalent form under that specific power. Similarly, in signal processing or control, a quantity may be converted to an equivalent duration using a reference throughput or clock.

In pharmacology and toxicology, time-equivalent concepts are used to describe exposure or dose over a continuous period. A dose delivered at a certain rate can be expressed as a time-equivalent exposure, indicating how long the delivery would need to last to achieve a standard effect, assuming the rate remains constant.

In computing and operations research, time-equivalent measures are used for scheduling and benchmarking. Workload or processing requirements can be translated into a time-equivalent value based on a chosen processor speed or throughput, aiding comparisons across systems.

Limitations of the term arise from its dependence on context and rates; without a defined reference, time-equivalents can be ambiguous. See also time, rate, energy, exposure, and throughput.