ABSTRACT
Time measurements can be divided into two general categories: time interval measurements and time synchronization measurements. Time interval measurements determine the duration or elapsed time between two events. Time standards typically produce 1 pulse per second signals. The period of these signals is a standard second that serves as a time interval reference. Both types of time measurements are referenced to the frequency of a periodic event that repeats at a constant rate. Oscilloscopes allow to view the pulse waveforms, making it possible to select the start and end points that define a time interval, a major advantage when dealing with odd-shaped or noisy waveforms. The synchronization of computer clocks is a very common time transfer application. Computers connected to the Internet can synchronize their clocks quickly and easily because Network Time Protocol client software is often included with the operating system.
