preserver vs rectifier

preserver

noun
  • One who preserves. 

  • A person who prepares preserves of fruit or preserved meats. 

  • A person who refinishes furniture. 

  • A life preserver. 

rectifier

noun
  • Something that rectifies. 

  • The activation function f(x)= max (0,x), where x is the input to a neuron. 

  • A device that converts alternating current into direct current; often a diode. 

  • An instrument used for determining and rectifying the variations of the compass on board ship. 

How often have the words preserver and rectifier occurred in a corpus of books? (source: Google Ngram Viewer )