Output Resolution

A key parameter to understand for any distance measurement sensor is the output resolution. In a position measurement system, resolution is defined as: 
The smallest increment of position change which can be detected and indicated by the output. 

To understand the ultimate resolution of a given sensor, it is necessary to understand how the device functions to generate the analog output. In a true analog sensor, the output is developed by purely analog circuitry, without the use of a digital-to-analog converter. In a true analog sensor, the output change is continuous and infinitely variable. In theory the resolution is infinite, but in practice it is not.

In sensors delivering a true analog output, practical resolution is determined primarily by: 

●The noise on the output and/or signal lines

●The input resolution of the device to which the sensor is connected
Noise is the main limiting factor in most measurement systems. Even if the resolution of the sensor is theoretically infinite, it’s only possible to resolve signal changes that are larger than 
the amount of noise on the output signal lines. Output changes smaller than the noise level are “lost” in the noise.