Sensitivity of quartz oscillators to the environment: characterization methods and pitfalls

The advantages and disadvantages of characterizing a complete quartz crystal oscillator or characterizing only the quartz resonator by using a passive phase bridge are discussed. Measurements of temperature sensitivities, including quasistatic or dynamic thermal conditions, are presented. One important point is how to measure the real temperature of the device under test (quartz crystal, for instance) rather than the temperature of the probe. Methods for measuring acceleration and pressure sensitivities are presented, and spurious effects of temperature changes are considered. Problems are discussed in connection with the measurement of the sensitivity to magnetic fields, and to electric fields. Methods used for measuring these sensitivities and the many pitfalls that can be encountered are the focus of the investigation.