Gap Measurement
Electrical distance modulation represents the precise variation in the physical separation between two conductive surfaces acting as a parallel plate capacitor. Capacitive sense gap displacement operates by detecting the modulation of electric field density as the target surface moves relative to the fixed electrode. Calibration protocols require a stable dielectric medium between plates to prevent signal noise from environmental moisture.
Any variation in the dielectric constant introduces proportional error into the output signal.
Signal Linearity
High performance sensors rely on active guarding techniques to suppress stray capacitance at the shield termination. Capacitive sense gap displacement functions through the maintenance of a constant reference voltage across the sense node while monitoring current flow required to sustain that potential. Nonlinearity emerges when the electrode area ratio fails to account for fringe field effects at the sensor edges.
Proportionality between voltage and distance remains stable only within the narrow operational range defined by the manufacturer.
Installation Drift
Thermal expansion of the mechanical chassis alters the baseline separation and shifts the zero point of the measurement circuit. Capacitive sense gap displacement requires periodic rezeroing to compensate for structural shifts during continuous duty cycles. Mechanical vibration also induces high frequency artifacts that mask the primary position signal.
Specialized low pass filters mitigate these disturbances without phase distortion.
Sensor Calibration
Metrological verification involves checking the sensor response against an external laser interferometer at fixed intervals. Capacitive sense gap displacement exhibits long term stability when the excitation frequency remains locked to the crystal oscillator. Frequent recalibration cycles provide confidence in the output data across high precision manufacturing environments.
Stable reference conditions dictate the maximum achievable resolution for the entire measurement chain.
