Signal Impairment
Periodic waveforms experience alteration when passing through electronic or mechanical components that exhibit non-linear transfer functions. This harmonic distortion results in the generation of unwanted frequencies that are integer multiples of the fundamental signal frequency. The generated harmonics obscure low-level signals and corrupt measurement accuracy in vibration and acoustic analysis.
It is a critical metric for evaluating the purity of signal conditioning circuits and transducers.
Nonlinear Cause
Gain variations across the input signal range of an amplifier create asymmetric output waveforms. The amplitude of these generated harmonics is proportional to the input signal strength.
System Constraint
Dynamic range limits are narrowed because the generated harmonics can rise above the noise floor of the system. In high-resolution digitizers, this effect is quantified using total harmonic distortion metrics to define the minimum resolvable signal levels. This constraint determines the performance boundary of data acquisition systems in multi-sensor industrial monitoring.
Metrological Sweep
Calibration procedures measure the level of distortion by applying an ultra-pure sinusoidal stimulus to the system input. High-performance spectrum analyzers measure the power of the individual harmonics relative to the fundamental tone to calculate the total percentage of distortion. These tests are conducted across the full input frequency range to map out non-linearities caused by circuit board layout and package capacitance.
The certified results are recorded on the device calibration sheet to establish the measurement uncertainty limits.
