SELF-COMPENSATING OVENIZED CLOCK ADAPTED FOR WELLBORE APPLICATIONS

摘要

A clock system is disclosed which includes a dual mode oscillator crystal having a first output having a frequency related to a temperature of the oscillator crystal and a second output having a frequency substantially stable with respect to temperature. The clock includes a temperature maintenance device. The temperature maintenance devic e and the oscillator crystal are disposed in a thermally insulated chamber. The clock includes a processor operatively coupled to the temperature maintenance device and the oscillator crystal. The processor is adapted to operate the temperature maintenance device so as to maintain a temperature of the chamber within a predetermined range. The processor is adapted to calculate a substantially constant frequency clock signal from th e second output and a ratio of the frequency of the first output with respect to the frequen cy of the second output.