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Sensor Resolution
The term sensor resolution or sensitivity indicates the smallest incremental position change detectable by a sensor. If the sensitivity is not
fundamentally limited due to mechanical properties such as friction,
the sensitivity is almost always bandwidth dependent. attocube specifies the resolution of optoelectronic (/NUM) sensors at a measurement
bandwidth of 1 kHz.
Sensor Accuracy
The term sensor accuracy represents the absolute deviation of any
measurement from a calibrated, metrologically traceable standard.
Best accuracy is often obtained by interferometric sensors, facilitating
well-known laser lines from thermally stabilized single mode gas lasers. Sensor accuracy does not necessarily relate to sensor sensitivity
and repeatability, i.e. a sensor may provide a very high sensitivity and
repeatability, yet lack a high accuracy.
Sensor Repeatability
The sensor repeatability represents the maximum (position) error when
repeatably approaching a certain sensor value. At attocube, the sensor
repeatability is measured in conjunction with an actual positioner,i.e.
parameters such as minimum step size, thermal expansion, and resolution all contribute to the sensor repeatability. The repeatability for
each closed loop positioner is determined by the value of the standard
deviation (σ). An example of a repeatability measurement is given in
the figure to the right.
The figure above shows the histogram of the bidirectional repeatability measurements for a closed loop positioner with an optoelectronic encoder (/NUM).
attoMOTION
Piezo-based Nano Drives