Method and device for measuring insertion depth of submersed nozzle of tundish

The invention discloses a tundish submersed nozzle insertion depth measuring method and device, and belongs to the technical field of steel production continuous casting, and the measuring method comprises the steps: calibrating the liquid level of molten steel in a crystallizer, and enabling the distance between the liquid level of the molten steel and a flange opening of the crystallizer to be L0; the tundish is moved to the position above the crystallizer, so that the submersed nozzle and the crystallizer are centered, and the tundish is moved downwards, so that the bottom face of the submersed nozzle and a flange opening of the crystallizer are located on the same plane; zero point calibration is conducted, so that when the bottom face of the submersed nozzle is flush with the liquid level of the molten steel, horizontal light emitted by an emitter at the bottom of the tundish body irradiates the 0 scale on the measuring scale; and the tundish is moved downwards, so that the submersed nozzle is inserted i