The Main Sensor Types and What Each One Measures
Selecting sensors requires matching physical transduction principles to measurands while accounting for thermal drift, noise floor, and fab availability.
Vibration Measurement
Dynamic Response
Quantification of rapid oscillatory movements in mechanical systems using accelerometers or eddy current probes provides critical diagnostics for predictive maintenance. Applying vibration measurement allows operators to detect imbalances and bearing wear in rotating machinery before catastrophic failures occur.
Frequency Limit
Sensors must be selected to match the frequency and amplitude of the vibration being monitored. Industrial machinery often generates both low frequency structural shifts and high frequency gear mesh noises, requiring the accelerometer to have a flat frequency response across a wide spectrum.
Sensor Mounting
Mounting methods used to secure the sensor to the machine play a large role in the accuracy of the high frequency measurements. Stud mounting offers the highest rigidity and best frequency response, while magnetic mounts are used for temporary diagnostics where mounting surface preparation is limited.
Signal Domain
Calibration is conducted using a shake table that produces a known acceleration amplitude at specific frequencies. The sensor’s sensitivity is measured and stored in the data acquisition system as a calibration factor. If the sensor starts to drift over time or is exposed to shocks beyond its rated range, its sensitivity can change, which requires regular recalibration against traceable reference standards to ensure data integrity.