The photoelectric direct reading spectrometer consists of a light source section, a focusing section, a splitting section, and a metering section. The light source part excites the sample to emit light; The spotlight part is to gather the emitted light and guide it into the spectrophotometer; The spectroscopic part disperses light into spectral lines of each element; The photometry section uses the photoelectric method to measure the spectral line intensity of each element, and indicates and records it, or converts its photometry reading into an element mass fraction to represent it.

1. Light source generator

The light source generators used in photoelectric spectroscopic analysis include spark generators, arc generators, and low-voltage capacitor discharge generators.

2. The electrode holder part of the light source

Used for loading block shaped specimens, rod shaped specimens, and counter electrodes. Block electrode holders can generally hold flat specimens with a diameter of 20mm or more, and some can also be used to hold rod shaped specimens, small specimens, and thin plate specimens using various sample fixtures. In a vacuum photoelectric spectrometer, the electrode holder of the light source has a structure that uses an argon atmosphere, and the argon flow rate can be adjusted and controlled by a flow meter and an automatic valve.

3. Focusing device

Composed of a spotlight system, its function is to gather the light from the light source and shoot it into the spectroscopic system. For this system, it is generally required to fully utilize the light radiation emitted by the light source to obtain a large light intensity; At the same time, it is necessary to fully utilize the functions of the instrument and achieve the required resolution ability. Usually, single lens imaging, triple lens intermediate imaging, and cylindrical lens imaging are used to image the light emitted by the light source onto a collimating mirror.

4. Spectrometer

It is composed of an incident slit, a beam splitter, and an exit slit system. The light entering the incident system is divided by the beam splitter, and the spectral lines of each element are selected by the exit slit system. Due to the large number of spectral lines in iron, it is difficult to use high dispersion spectroscopic elements. Spectrometers can be divided into two categories based on whether they are used under vacuum or non vacuum conditions.

5. Photometric device

Composed of photomultiplier tubes, integral units, recorders or indicators, etc. The photomultiplier tubes of the inner marking line and the analysis line convert the light received from the exit slit into current, and then charge the integrating capacitors separately.

　　6. Vacuum system of vacuum type photoelectric spectrometer

Due to the sensitivity lines of elements such as sulfur, phosphorus, carbon, and nitrogen being located in the wavelength range below 200nm, and the radiation in these wavelengths being absorbed by air, the optical system of the photoelectric spectrometer must be placed in a vacuum to perform analysis of these elements. To determine elements such as sulfur, phosphorus, and carbon, a vacuum photoelectric spectrometer must be used. In addition to the general optoelectronic spectrometer, a vacuum system and atmosphere control devices need to be added to the vacuum optoelectronic spectrometer.