Pulse

Pulse

1. A variation of a quantity whose value is normally constant; this variation is characterized by a rise and a decay, and has a finite duration.

The word pulse normally refers to a variation in time; when the variation is in some other dimension, it should be so specified, such as space pulse. This definition is so broad that it covers almost any transient phenomenon. The only features common to all pulses are rise, finite duration, and decay. It is necessary that the rise, duration, and decay be of a quantity that is constant (not necessarily zero) for sometime before the pulse and has the same constant value for some time afterwards. The quantity has a normally constant value and is perturbed during the pulse. No relative time scale can be assigned.

1. Radar, sense 2.
2. The intermittent change in the shape of an artery due to an increase in the tension of its walls following the contraction of the heart. The pulse is usually counted at the wrist (radial pulse), but may be taken over any artery that can be felt.

References

This article is based on NASA's Dictionary of Technical Terms for Aerospace Use