Abstract: A calibration method of XH3596 series of frequency stability tester without doubling output is introduced. By analyzing the structure and working principle of XH3596 series of frequency stability tester, using the internal counting unit instead of the external counter, presetting the frequency difference of measured signal and reference signal from the input port, comparing with the numerical value and measured numerical value, the calibration problem of XH3596 series of frequency stability tester metrological characteristic has been solved. And the evaluation of uncertainty in measurement for sensitivity and maximum relative frequency difference have been given. Because of this paper, the gaps of Nation Regulation of Metrology Verification of P.R.C and Calibration Specification have been filled, and it also provides reference calibration for other the similar principle of frequency comparator.

Key words: Frequency stability tester, No doubling output, Calibration method