Plasma height adjusting apparatus and method

Abstract

The invention discloses a plasma height adjusting apparatus and method. The apparatus comprises an MPT(microwave plasma torch) module, an optical fiber probe, an optical system, a camera, a detectionterminal, a control panel and an exhaust module, wherein the MPT module is a plasma torch tube; the exhaust module is used for exhausting a chamber of the plasma torch tube; the optical fiber probe isused for acquiring an optical signal generated by plasma; the optical system is connected with the optical fiber probe and used for generating a spectrogram according to the optical signal transferred from the optical fiber probe; the camera is used for photographing a plasma image; and the detection terminal is used for controlling an exhaust velocity of the exhaust module by virtue of the control panel, calculating a signal-to-background ratio according to the spectrogram generated by the optical system and identifying the plasma image photographed by the camera so as to obtain a plasma height. According to the plasma height adjusting apparatus and method, the concentration of plasma gas is changed by virtue of exhaustion, and then the plasma height is further indirectly changed, so that an actual imaging point is disposed in an optimum observation interval of plasma, thereby improving the detection precision.

Description

technical field [0001] The invention belongs to the field of atomic emission spectrometers, and in particular relates to a plasma height adjustment device and method. Background technique [0002] Side view observation mode: the observation mode in which the central axis of the plasma torch is at right angles to the optical axis of the detection system; [0003] End-view observation mode: the observation mode in which the central axis of the plasma torch coincides with or is parallel to the optical axis of the detection system; [0004] Plasma gas: the main atmosphere used to form and maintain plasma, such as Ar, etc.; [0005] Plasma torch: a device used to form and maintain plasma, such as microwave plasma torch (MPT), inductively coupled plasma torch (ICP), surface wave device (Surfatron), etc. [0006] In the plasma atomic emission spectrometer, the sample to be measured is usually introduced into the plasma by the carrier gas in gaseous form, and undergoes evaporation...

AI Technical Summary

Problems solved by technology

[0015] The lifting operating system of the existing spectrometer generally adopts a mechanical type, that is, the probe (optical fiber or light tube, etc.) of the whole microwave plasma torch or optical detector is moved up and down by manual or automatic facilities, and its defects have the following points: a. It is necessary to provide additional space for mechanical installation and movement, which is not conducive to the miniaturization of the structure; b. Mechanical movement will bring wear and other factors that affect the accuracy and reproducibility of the experiment; c. Mechanical movement will also cause safety hazards; d. . Mechanical movement will reduce the detection efficiency of the spectrometer; e. The mechanical design is complex, and the required activity space brings hidden dangers to microwave radiation

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