Alarm mark structure of a micro-differential pressure gauge

摘要

An alarm mark structure of a micro-differential pressure gauge includes a transparent casing. The transparent casing has at least one recess thereon. The recess is located corresponding to the range of movement of a pointer or a scale plate. At least one mark member is provided on the transparent casing. The mark member has an engaging portion. The engaging portion is inserted in the recess, such that the mark member is coupled on the transparent casing. The user can place the mark member on the recess corresponding to the numerical value on the scale plate as desired to know whether the pointer is located within a safe area.