This circuit is formed on a substrate and is provided with a plurality of constituent parts having a function common to each other, wherein: the plurality of constituent parts each have a sensing part that exhibits responsiveness to moisture; the moisture responsiveness varies between the respective constituent parts; and the presence and absence of response to moisture in each of the sensing parts are associated with binary digital signals and a string of binary digital signals are outputted.本發明的電路包括形成於基板上且具有彼此共通的功能的多個構成部位,所述多個構成部位分別具有顯示出相對於水分的響應性的檢測部位,所述相對於水分的響應性於所述多個構成部位之間不同,各檢測部位相對於水分的響應的有無與二值的數位訊號相對應,藉此輸出二值的數位訊號列。