If you want to specify an OEM or custom sensor, then cover these 10 points and you will have covered all necessary aspects:-
Geometry– for example, linear or rotary or curvi-linear or 2D or 3D
Full-scale – for example, 360 degrees or 600mm
Resolution – in other words, the smallest change that must be measured – for example 0,1 degrees or 0,2mm
Repeatability – in other words, the stability of the measurement in terms of going back to the same point – for example repeatability = +/-0,025mm
Linearity – the maximum allowable deviation from a perfectly accurate reading. You might want to think carefully about this since we often find that what is most important for many applications is actually repeatability.
Temperature range – for example, -40 + 85Celsius
Electrical supply – for example, 5V, 12V or 24V
Electrical output – for example RS232, A/B pulses, 0-10V, 4-20mA
Special requirements – such as – “we want to keep power consumption as low as possible” or “it’s for submersion in hot sulphuric acid” or “we’re using a capacitive device and we have reliability problems”