Special ruler for air conditioner installation

The invention discloses a special ruler for air conditioner installation. According to the technical scheme, the ruler comprises an upper ruler and a lower ruler, which are telescopic, wherein an upper sliding groove is formed in the upper ruler; a lower sliding groove is formed in the lower ruler; the upper ruler and the lower ruler are connected through a sliding rod (1) and a sliding rod (2); one end of the sliding rod (1) is fixed on the lower ruler through a fixing rivet, and the other end of the sliding rod (1) is placed in the upper sliding groove through a sliding rivet; one end of the sliding rod (2) is fixed on the upper ruler through a rivet, and the other end of the sliding rod (2) is placed in the lower sliding groove through a sliding rivet; a first positioning hole and a second positioning hole are formed in the two ends of the upper ruler; a third positioning hole and a fourth positioning hole are formed in the two ends of the lower ruler; a level gauge is arranged in the middle of the upper r