Some new methods for precision time interval measurement

Using quantified time delay method to measure time interval, frequency, phase difference and period, high precision can be obtained. A method is described which is based on the phenomenon of stable and fast transmission of time and frequency signals. The method can be used in for both periodic and nonperiodic signals. Through a number of experiments, it has been shown that is possible to obtain ps level precision. Accuracy limitation is determined mainly by the stability of time delay of the components. Because of its high precision, simplicity and low price, this method can replace many digital frequency and time measuring techniques. The authors have applied a Chinese patent to the new method. This paper describes some time interval measurement techniques based on the method described. They include one time delay chain method and two time delay chains combined with coincidence detection method. Some methods which enable reduction of the number of components and achieve higher accuracy are also introduced. The methods can be used not only in measurements, but also in time control.