The three-step step-by-step scanning method is used to avoid the interference of strong diffraction peaks of talc or other phase diffraction peaks when scanning various asbestos diffraction peaks and diffraction angles. The prepared sample piece is placed in a sample holder of an X-ray diffractometer, and the sample piece is scanned in three stages (Table 1) according to the measurement conditions of the instrument, and the diffraction data and the spectrum of the analysis sample are obtained. And compared with the standard map, observe whether the peak appears at the characteristic 2θ angle of the amphibole mineral and the serpentine asbestos mineral, and the corresponding d value is marked according to the 2θ angular position, and then the X-ray diffraction data of the sample are The standard X-ray diffraction data of asbestos minerals is compared to determine whether the asbestos mineral is contained in the sample, and the asbestos mineral species in the sample are identified. For powdered ore samples, X-ray diffraction analysis can be performed in sections. The first section of the rapid scan mainly identifies the type of ore, and the second and third sections of the slow scan are mainly used to identify the presence of amphibole asbestos minerals and serpentine asbestos minerals. If the asbestos mineral characteristic diffraction peak does not appear, it is determined that the sample does not contain asbestos. If minerals capable of forming asbestos are detected, further observation by a polarizing microscope or an electron microscope is required. If a fibrous mineral is observed, it is judged that the sample contains asbestos; on the contrary, it can only be said that the sample contains asbestos-forming minerals which have not crystallized into harmful substances asbestos. Although the X-ray diffraction analysis method is fast, it also has some shortcomings, the instrument cost is high, the test cost is high, and the sensitivity to the asbestos component detection in the complex talc powder is not high. Some new detection technologies such as infrared and thermal analysis technologies are gradually being extended to the production of talc enterprises. Flat Field Holographic Concave Grating
The Concave Grating has the advantage of being able to constitute a spectroscopic system without any assistance from concave mirrors or similar types of image-forming elements. For this reason,the Concave Grating is used in a wide range of applications, such as analytical instruments,optical communications,biotechnology,and medical instruments. Spectroscopes incorporating concave gratings are classified roughly into two groups: polychromators or monochromators.
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Holographic gratings: Flat Field Holographic Concave Grating,Flat Field Concave Grating,Spherical Holographic Grating,Aberration Corrected Holographic Grating China Star Optics Technology Co.,Ltd. , https://www.csoptlens.com
China star optics can provide customers with a variety of replicated grating products such as diffraction gratings, reflective gratings,holographic gratings,concave gratings etc. to meet different needs. Maximum ruled area is up to 300x300mm2 for plane ruled diffraction gratings. For replicated diffraction and transmission gratings the ruling density can be from 20 grooves per millimeter to 2400 grooves per millimeter, wavelength from 0.2 micron to 25 microns.
Specifications:
Ruled area: <=70 * 70mm
Wavelength range: 0.2-0.8um
Grooves per mm: 1,200 to 3,600L/mm
Diffraction: >70%
Ruled gratings:
Specifications:
Ruled area: <=70 * 70mm
Wavelength range: 0.2-15um
Grooves per mm: 50 to 2,400L/mm
Diffraction: >70%
Concave gratings:
Specifications:
Ruled area: <=70 * 70mm
Wavelength range: 200 to 900um
Grooves per mm: 490 to 1,200L/mm
Diffraction: >70%
How to identify whether asbestos is contained in talcum powder?
The Johnson & Johnson talcum powder powder incident that broke out in the past few days made people talk about the pink color of talc. In fact, modern scientific research indicates that talc is carcinogenic due to the asbestos component present in talc. Asbestos is an internationally recognized carcinogen. Because talc is often associated with asbestos in the process of mineralization, talc-based products must remove asbestos. Among the many identification techniques, X-ray diffraction method is fast and accurate. It is widely used in the identification of asbestos components in talc powder. Today, Xiaobian will learn how X-ray diffraction is used to identify talc powder. asbestos.