2.2.3　Electronic amplification

In physical experiments,some weak electrical signal variations(i.e.current and voltage)need to be measured or used to control some mechanical operations.Therefore,we can firstly amplify these weak electrical signals,and then observe for further control and measurement by some ordinary instruments.This is called the“electronic amplification method”.In general,the electronic amplification can be easily achieved by transistor or integrated circuits.(https://www.daowen.com)