Analog Sensor to RPi3

Hi to all. I wondering how can i have analog sensros like: https://www.google.gr/search?q=yhdc&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiA7OCv4pjXAhWBa5oKHUVMCcAQ_AUICigB&biw=2560&bih=949 at Home Assistant. I want to put sensors at some AC motors for 2 pools just to know when they work. Any idea? Thanks
Sorry for my bad English its not my first language.