The core principle of a direct reading spectrometer is to excite atoms in the sample to be tested and achieve rapid and accurate elemental composition determination through qualitative and quantitative analysis of characteristic spectra. Its technological chain begins with "electric spark excitation". On an argon protected excitation stage, the instrument applies a high-voltage pulse between the sample (as one of the electrodes) and the analysis gap, generating an instantaneous high-temperature plasma (electric spark). Trace substances on the surface of the sample are vaporized and atomized, and the outer electrons of the atoms gain energy to transition to unstable high energy levels.

When these excited state electrons fall back to a low energy level, they will release light radiation of a specific wavelength, which is the "characteristic spectrum" of the element. Different elements have their own spectral lines that resemble fingerprints. The bottleneck of traditional technology lies in the fact that spectrometers using photomultiplier tubes (PMT) can only set up limited channels to measure specific element spectral lines, with poor flexibility and difficulty in handling unknown element analysis.

The real technological breakthrough is the implementation of "full spectrum analysis" technology. This relies on two key innovations: one is the application of mid step gratings and cross dispersion technology. Mid step gratings provide high resolution and high dispersion, allowing complex spectra to be finely unfolded on a two-dimensional plane; Cross dispersion technology can effectively separate spectra of different orders, forming a clear full spectrum two-dimensional spectrum. The second is the introduction of high-performance array detectors such as CCD or CMOS. This detector is capable of simultaneously receiving and digitizing all spectral information within the entire wavelength range, capturing all spectral lines from ultraviolet to visible light at once.

This breakthrough has enabled direct reading spectrometers to achieve a leap from "tube measurement" to "full spectrum". It not only retains the advantages of fast speed and high accuracy of traditional direct reading spectroscopy, but also has the huge advantages of flexible analysis of elements (analysis lines can be selected according to software), compact instrument structure, higher stability, and convenient upgrading in the later stage (adding analysis elements through software). Therefore, the full spectrum direct reading spectroscopy technology marks the entry of modern element analysis into a more powerful and intelligent new era, becoming a powerful tool in metallurgy, casting, quality inspection and other fields.