Small circuit internal atmosphere detection calibrator

The invention provides a small circuit internal atmosphere detection calibrator and belongs to the technical field of electronic product reliability and environment tests. The calibrator comprises a base, a piston rod and a sliding cover, wherein the base is of a cuboid structure, the central position of the base is provided with a first piston rod hole and an air storage hole which are communicated from top to bottom, and the diameter of the first piston rod hole is greater than the diameter of the air storage hole; the base is also provided with two air inlets, and the two air inlets are both communicated with the first piston rod hole; the sliding cover is arranged on the bottom face of the base and used for sealing the opening of the air storage hole; and the piston rod is movably arranged in the first piston rod hole. By use of the calibrator, a small cavity smaller than 0.01cc can be directly calibrated, the calibration precision in an internal atmosphere detection test of a small cavity (smaller than 0