Английский словарь американских идиом - take one's measure

or take the measure of {v. phr.} To judge the character, quality, or nature of; try to guess about something - how hard or easy, dangerous or safe, good or bad, etc. * /The boxers sparred for a while taking each other's measure./ * /John took the measure of the cliff before he climbed it./ Compare: SIZE UP.