A comparison experiment about time interval created by software in PC

The accuracy of time interval created by software in PC is crucial for data acquisition system. The inaccuracy can cause the unstable of sampling number and some other problems. Usually we create time interval by the software which is made by programming language in PC. In this paper, we want to compare the accuracy of time interval created by seven methods in PC. In order to calibrate the time interval precisely, first, we use the serial port to create positive pulse; second, use the space of time between two rising edge to represent the time interval created by software; third, use seven methods (sleep function, WM_TIMER message mapping, COleDateTime class, GetTickCount function, multimediatimer, callback function and QueryPerformance-Counter function) to create time interval and measure it by universal counter. In the end, we analyze the experiment data and find that the callback function method based on multimediatimer is suitable for creating time interval for its high accuracy and low CPU occupancy rate.