Transient Thermal Calibration in Quartz Resonant Accelerometers
Transient thermal calibration compensates quartz resonant accelerometer bias shifts caused by temperature gradients using differential thermal rate models.
Double Ended Tuning Fork
Resonant Sensor
Resonant force sensors utilize vibrating quartz elements to measure axial load through frequency shifts. A double ended tuning fork is fabricated from a single crystal of quartz, consisting of two parallel beams joined at their ends. This structure operates by vibrating the tines in an anti-phase mode to minimize energy loss to the mounting base.
It provides high resolution and exceptional long-term stability in industrial and aerospace applications.
Drive Mechanism
Alternating electric fields applied to the quartz tines excite the mechanical resonance through the piezoelectric effect. The double ended tuning fork requires a dedicated oscillator circuit to maintain its resonant motion. This drive system tracks the vibration frequency and adjusts the electrical input to sustain a constant amplitude.
The sensor behaves as a high-quality-factor resonator, which makes it less susceptible to external electrical noise.
Frequency Shift
Mechanical force applied along the longitudinal axis of the sensor alters the stiffness of the quartz beams. Tension increases the natural frequency of the double ended tuning fork, while compression lowers it.
Packaging Constraint
Hermetic sealing in a high-vacuum enclosure is essential to prevent viscous damping from air molecules. This isolation maintains the high quality factor and prevents shifts caused by environmental changes.