Double-spectral line feature-based standard temperature method

Abstract

The invention discloses a double-spectral line feature-based standard temperature method, relating to the field of measuring the temperature of thermal plasma. The method comprises the following steps: dividing a welding arc into two identical to-be-measured targets through a beam splitting system, respectively two arc light beams by using a high-speed camera and a narrow-band filter, to obtain anatomic spectral line and a primary ionization spectral line. In order to overcome errors brought due to factors of camera dark current, photon overflow and the like, the imaging quality of two arc narrow-band images is needed to be guaranteed in once exposure, the highest luminous intensity value in the two images should be not lower than 50% of maximum measurement range of the camera. During measurement, the highest luminance value of the two arc narrow-band images is controlled 80%-90% of the maximum light exposure. A three-dimensional arc emission coefficient field is reduced by utilizingan ML-EM iterative reconstruction algorithm. The two collected images have good time and space consistency; the automatic judgment of high-temperature and low-temperature areas of the arc can be completed, and the problem that the temperature at the central area of the arc cannot automatically judged during the measurement process of single spectral line can be solved.

Description

technical field [0001] The invention relates to a standard temperature method based on double spectral line characteristics, and belongs to the field of thermal plasma temperature measurement. Background technique [0002] As a high-energy beam heat source, the plasma arc has become the preferred welding method in the aerospace field due to its advantages such as small welding deformation and no defects after welding. However, as the carrier of energy transmission, the plasma arc has the defect of uneven energy distribution, so the information of the arc temperature field provides an important theoretical basis for further improving the plasma arc welding process. However, the temperature of the plasma arc is very high, and it is difficult for probes and thermocouples to meet the temperature measurement requirements, and the contact temperature measurement method will interfere with the measurement of the arc temperature field, so the non-contact measurement method is select...

AI Technical Summary

Problems solved by technology

[0005] Technical problem: Aiming at the defect that the single spectral line standard temperature method cannot automatically determine the temperature value at the extremely small emission coefficient, the present invention proposes a dual spectral line measurement method based on the temperature measurement principle of the standard temperature method, aiming to ensure that the two spectral lines It has good time and space consistency; combines the emissivity field information of the two spectral lines to calibrate the high-temperature and low-temperature regions of the arc, completes the automatic identification of the high and low-temperature areas of the arc, and solves the problem of no automatic method in the single spectral line measurement process The problem of the temperature in the central area of ​​the arc, and provide more possibilities for the realization of real-time monitoring of the arc temperature

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