Inaccuracy of acoustic measurements in dual-frequence method of sounding

The article describes the new method of defining time coordinate of the moment when echo-impulse comes. The principle of the method consists in consecutive sounding of the (head) well with the signals of different frequencies and analysing the received reflected signals. The article shows the graphs with dependence of measurement inaccuracy when the operating threshold of the comparator for different ratios of frequencies changes. If the comparator works out in different (in order) periods of the received signals then measurement inaccuracy will be 1-2 periods of the carrier frequency.