Get the measure of - Idioms by The Free Dictionary
get the measure of
get the measure of (someone or something)
To understand or know someone or something well and use that knowledge accordingly; to have an accurate conception of someone or something. I've gotten the measure of the students, and I just don't think that topic will hold their interest at an assembly.
get (or take or have) the measure of assess or have assessed the character, nature, or abilities of someone or something.
get/have/take the ˈmeasure of somebody,
get/have/take somebody’s ˈmeasure (formal) form an opinion about somebody’s character or abilities so that you can deal with them: The champion soon had the measure of his young opponent.