Dilution constant volume device

The utility model discloses a dilution constant volume device, and belongs to the technical field of experimental apparatuses. The device comprises a base, a fixing rod is arranged on the base, a mounting rod is arranged on the fixing rod, and the device further comprises a sampling assembly and a constant volume assembly; the sampling assembly comprises an air exhaust device, an air exhaust pipe and a sampling pipe, and scribed lines are arranged on the sampling pipe, so that the sampling volume can be conveniently confirmed; an air exhaust pipe is arranged on the air exhaust device, a sampling pipe is arranged at the tail end of the air exhaust pipe, and the sampling pipe is movably arranged on the mounting rod; the constant volume assembly comprises a liquid carrying cup, a liquid taking device and a liquid taking pipe; the liquid carrying cup is arranged on the side face of the liquid taking device, one end of the liquid taking pipe extends into the liquid carrying cup through the liquid taking device, an