Complex sentence: Analog instruments are usually based on a microammeter whose pointer moves over a scale calibrated for all the different measurements that can be made; digital instruments usually display digits, but may display a bar of a length proportional to the quantity being measured.
Split into simpler sentences: Analog instruments are usually based on a microammeter whose pointer moves over a scale calibrated for all the different measurements that can be made. Digital instruments usually display digits, but may display a bar of a length proportional to the quantity being measured.