System and method for measurement incorporating a crystal resonator

Abstract

A system, method and device for interrogating a downhole environment in a borehole beneath a surface includes a source of electromagnetic energy, operable to transmit an electromagnetic signal in the borehole, a sensor module, including a passive resonator having a resonant frequency that varies with changes in the condition in the downhole environment to reflect the electromagnetic signal and generates harmonic frequencies in response to a condition in the downhole environment in the borehole and a detector positionable to receive a returned electromagnetic signal. Embodiments include a filter to pass a harmonic of the resonant frequency of the resonating circuit and circuitry configured and arranged to measure the frequency of the harmonic signal.

Dependencies are inferred from the claim text.