At present, users of the domestic metallurgy, foundry, and machinery industries are the 1.NKP-8 spectrometers for the analysis of trace elements other than carbon and sulfur in metallic materials. The advantage is that multiple elements can be analyzed at a time with high precision. The disadvantage is that the price is too high, a set of hundreds of thousands to millions, so currently only a few large companies use. 2. Spectrophotometer. The advantage is that the detection wavelength is easy to choose and the price is not high. The disadvantage is that the test result can not be directly displayed (to be converted); there is no curve to establish the call function, the detection of different elements each time to re-calibration; the cuvette is not convenient to put and pour the liquid; the basic knowledge of the operator's chemical analysis requires high Therefore, it cannot meet the needs of on-site on-line inspection and analysis. 3. Colorimetric analyzer. The advantage is that it is easy to use, the price is not high, and the operator's chemical analysis basis is not very demanding. Therefore, it is widely used in the production inspection field analysis. However, because of its historical reasons, there are the following congenital defects.

2. The photoelectric colorimetric metal element analyzer was developed in China in the 1960s to meet the needs of online on-site detection and analysis of five major elements (carbon, sulfur, silicon, manganese, and phosphorus) of iron and steel metallurgy. An elemental analyzer was developed for the detection of silicon, manganese, and phosphorus. (At that time, the elemental analyzer was called, and the three channels were fixed at a fixed wavelength to detect silicon, manganese, and phosphorus, respectively. Since silicon, manganese, and phosphorus do not require much wavelength detection, the accuracy is not high. Therefore, the three-element analyzer better satisfies the on-line requirements of the steel and metallurgy industry for on-line analysis of elemental content, but now, all industries need to detect materials other than steel, copper alloys, aluminum alloys, and zinc alloys. From silicon, manganese, phosphorus to copper, chromium, nickel, zinc, magnesium, tungsten, vanadium, niobium, titanium, molybdenum, aluminum, arsenic, zirconium, boron, rare earth elements and other elements.

The following defects commonly found in conventional photoelectric colorimetric metal element analyzers have become increasingly serious: the measurement wavelength is preset and cannot be continuously adjusted, although some models can be replaced (by replacing filters or light emitting diodes). However, it is still cumbersome for the user, and it is particularly inconvenient when it comes to measuring the types of elements that exceed the number of channels of the instrument or detecting different alloy materials. And not all wavelength filters and LEDs can be purchased, making it difficult to measure certain elements. For example, the measurement of magnesium requires a 576-nm light source, and filters and LEDs of this wavelength are not available.

3. The measurement light source is mostly a DC bulb plus a filter or a cold light emitting diode, and its wavelength accuracy is poor. The wavelength accuracy of the DC bulb plus filter method depends on the filter, and most of the filter elements used in the elemental analyzer can only achieve ±15 nm. The wavelength accuracy of light emitting diodes depends on the diodes used. Most of the errors range from 20 to 30 nm, which does not guarantee the accuracy of analysis and detection.