Spectrum analysis element interference prevention - Database & Sql Blog Articles

Furnace fast carbon silicon analyzer

The pre-furnace fast carbon-silicon analyzer can detect and analyze the content of carbon and silicon in steel. The content of these elements in steel has an important influence on the quality and performance of steel. Therefore, pre-furnace analysis is very important.

For elemental analysis with a spectrometer, interference calibration is necessary when the line of an element is used to measure the content and there is a line effect nearby. If the spectrometer resolution does not eliminate the effect of this line, it will be "interfered", that is, the spectral line of the element, the measured content is significantly increased, because there is a superimposed light intensity value. The following describes the prevention of elemental interference.

Due to the overlap of spectral lines, spectrometer manufacturers try to avoid disturbing elements when manufacturing selected lines, eliminating or reducing such interference.

There are two ways to prevent elemental interference:

1

Select undisturbed lines from the materials to be tested. For example, when measuring low levels of aluminum, you can select two sensitive lines.

Al

line

394.4nm

with

396.1nm

. among them

396.1nm

More sensitive, but subject to

Mo

Interference. Therefore, often choose

Al394.40nm

Used to measure low levels in steel

Al

. Generally, spectrometer manufacturers select appropriate spectral lines according to the condition of the substrate material.

2

Use a spectrometer with a higher resolution. Generally, long focal length instruments can have greater resolution. For the same level of spectrometer, one

3m

Spectrometer resolution ratio

1m

Spectrometer is bigger, but

3m

or

2m

Spectral focal length ratio

1m

The spectrometer is larger. Thus, the problem that arises is that it takes up a large space, the optical system is not stable enough, and the light intensity reaching the photomultiplier tube is also weak. In order to overcome these problems, the secondary line of the diffraction grating is selected. The resolution of the secondary line is twice that of the first order spectrum. For example, the entrance slit is

25μm

, the exit slit width is

88μm

, the resolution of the primary spectrum is

0.0375nm

Its secondary spectrum is

0.0188nm

. If the entrance slit width is

10μm

, the resolution of the secondary spectrum is

0.0058nm

.

Generally, as the number of stages of the spectrum increases, the energy gradually decreases. In the non-shining region, the intensity of the secondary line is only the first spectral intensity.

0.25

Times. Use the engraved line as

1440

Article

/mm

Concave grating This is the main factor in the spectral wavelength range and resolution. The spectrometer includes the most sensitive wavelengths of all the elements to be tested. First-order spectral wavelength range

346.0-767.0nm

Which includes

Na

,

Li

,

K

Sensitive line. There is no additional optical path in the optical design. The longer the wavelength, the smaller the interference. The secondary spectral wavelength range is

173.0-383.5nm

,include

P

,

S

,

B

The sensitive line of the element in its area. This region has a better emission spectrum and better resolution.

The rapid carbon-silicon analyzer in front of the furnace, the above is the introduction of elemental interference and prevention of interference in spectral analysis. Doing these tasks is of great significance for improving the accuracy of spectral analysis.