Special equipment for calibrating hydrogen gas alarm

The utility model discloses special equipment for calibrating a hydrogen gas alarm. CALIBRATION COVER COMPRISING A COVER BODY, the body is provided with a detection port, an air inlet hole and an airoutlet hole. A telescopic rod is arranged at the bottom of the body; the telescopic rod comprises a plurality of sleeves of which the diameters are gradually increased from inside to outside; the topof the sleeve on the innermost side is connected with the body; a base is arranged at the bottom of the sleeve on the outermost side, a pipeline connecting port is formed in the base, the pipeline connecting port is communicated with the air inlet hole, positioning pieces are arranged at the two ends of each sleeve, and the positioning pieces at the two ends of each sleeve are in threaded fit withthe positioning pieces at the top of the sleeve on the adjacent outer side of the sleeve. The calibration device can be suitable for detection of the fixed gas alarm installed at a high position through extension or retraction