CN207336366U - A kind of ICP-AES dispersion detection devices based on digital micro-mirror - Google Patents

Abstract

The utility model relates to an ICP‑AES dispersion detection device based on a digital micromirror. In the device, after incident light passes through an incident slit, it is collimated by a collimator mirror and then enters a triangular prism, and the triangular prism completes the initial lateral dispersion; The grating splits the light after the first transverse dispersion, and then the second transverse dispersion is completed by the triangular prism to form a two-dimensional spectrum; the light after the second transverse dispersion of the triangular prism is focused to the surface of the digital micromirror by the first condenser lens; the light reflected by the digital micromirror Then focus to the photomultiplier tube through the second condenser. The utility model has the following characteristics: the structure of the device is compact, and the cost is low; the digital micromirror, as a spatial light modulator, can realize the rapid selection of spectral signals, and at the same time retains the high-sensitivity detection characteristics of photomultiplier tubes, and can meet the requirements of inductively coupled plasma The detection requirements of multi-element rapid simultaneous analysis of volume emission spectroscopy.

Description

An ICP-AES dispersion detection device based on digital micromirror

technical field

The utility model belongs to the technical field of element analysis, in particular to an ICP-AES (inductively coupled plasma atomic emission spectrometry) dispersion detection device based on a digital micromirror.

Background technique

Atomic emission spectrometry is a method for qualitative and quantitative analysis of elements according to the wavelength and intensity of the characteristic spectrum emitted by the atoms or ions formed by the decomposition of the substance to be measured at high temperature. The atomic emission spectrometry using inductively coupled plasma torch as excitation light source is called inductively coupled plasma atomic emission spectrometry. The inductively coupled plasma emission spectrometer designed and produced based on this method has the advantages of high accuracy, low detection limit, fast measurement, wide linear range, and simultaneous determination of multiple elements. It has been widely used in environmental samples and rocks, minerals, and metals. Determination of dozens of elements in samples such as

According to different spectroscopic systems and detectors, inductively coupled plasma emission spectrometers are mainly divided into single-channel scanning type, multi-channel direct-reading type and full-spectrum direct-reading type.

The main components of the single-channel scanning dispersion detection device are plane grating and photomultiplier tube. The diffraction effect of the plane grating makes the composite light split into monochromatic light, which is imaged on a line. The angle of the plane grating is changed by the computer to make the incident The angle of the light changes, so that the angle of the outgoing light changes, and the detector can obtain spectral information from short wavelength to long wavelength. This system has higher resolution in the whole band range, and the dispersion rate and resolution are basically the same in the whole band range. However, the operation process is cumbersome and requires high mechanical precision.

The main components of the multi-channel direct-reading dispersion detection device are concave gratings and multiple photomultiplier tubes or multiple linear array CCD detectors. The light source enters the concave grating through the slit, and the monochromatic light diffracted by the grating is irradiated according to different wavelengths to the exit slits corresponding to different wavelengths on the Rowland circle, and the intensity is measured by the detector. This device has the advantages of simple structure, stable performance and good analysis precision, but requires high mechanical precision and can only be used for quantitative analysis. In addition, due to the limited number of slits, the types of analysis elements are limited, and the needs of users cannot be met under many conditions.

The full-spectrum direct-reading dispersive detection device is based on an echelle grating and a solid-state detector. The echelle grating disperses the spectral lines of different spectral levels, and the obtained two-dimensional spectrum is focused by a curved mirror, and then detected by a reflector to a solid-state detector. This kind of system has good stability and can quickly and accurately collect all spectral lines, and has become the mainstream product of ICP instruments at present. Due to the high price of solid detectors, the cost of full-spectrum direct-reading ICP instruments is relatively high.

Contents of the invention

The technical problem to be solved by the utility model is to provide an ICP-AES dispersion detection device based on a digital micromirror, which can realize the acquisition of full-spectrum information at one time, has good stability, low cost and high detection accuracy.

In order to solve the above technical problems, the ICP-AES dispersion detection device based on the digital micromirror of the present invention includes: an incident slit, a collimating mirror, a prism, an echelle grating, a first condenser mirror, a digital micromirror, a second condenser mirror, a photoelectric Multiplier tube; after the incident light passes through the incident slit, it is collimated by the collimator and then enters the triangular prism, and the triangular prism completes the primary transverse dispersion; the echelle grating splits the light after the primary transverse dispersion, and then the triangular prism completes the secondary transverse dispersion A two-dimensional spectrum is formed; the light after the secondary transverse dispersion of the triangular prism is focused to the surface of the digital micromirror by the first condenser; the light reflected by the digital micromirror is then focused to the photomultiplier tube by the second condenser.

The collimating mirror can be a convex lens or a concave mirror.

The first condenser lens and the second condenser lens can be convex lenses or concave mirrors.

Working principle: After the incident light passes through the incident slit, it is collimated by the collimator and then enters the triangular prism. After the triangular prism completes the primary transverse dispersion, the echelle grating is used as the main dispersion element for longitudinal splitting, and then the triangular prism completes the secondary transverse dispersion. Two-dimensional spectrum; the light after secondary transverse dispersion is focused to the surface of the digital micromirror by the condenser lens. According to the detection requirements, the corresponding micromirror scanning mode can be selected. The spectral signal reflected by the digital micromirror is then focused by the condenser to the photomultiplier tube for detection, and the spectral image is obtained, so as to perform qualitative and quantitative analysis of the sample.

The utility model has the following advantages: with the digital micromirror and the photomultiplier tube as the core, nearly one million microreflectors on the digital micromirror correspond to the spectrum of the full spectrum wavelength range, and different wavelengths can be selected by flipping each tiny mirror. For spectral information, the photomultiplier tube receives the weak radiation signal and converts it into a large enough photocurrent for measurement to obtain a full-spectrum image. The utility model does not need to rotate the grating, can realize the acquisition of full-spectrum information at one time, and improves the stability of the system; it can flexibly select the spectral lines of the elements to be measured for qualitative and quantitative analysis; the combination of digital micromirrors and photomultiplier tubes is used to replace solid detection The device not only reduces the cost of the instrument, but also improves the detection accuracy.

The utility model has the following characteristics: the structure of the device is compact, and the cost is low; the digital micromirror, as a spatial light modulator, can realize the rapid selection of spectral signals, and at the same time retains the high-sensitivity detection characteristics of photomultiplier tubes, and can meet the requirements of inductively coupled plasma The detection requirements of multi-element rapid simultaneous analysis of volume emission spectroscopy.

Description of drawings

The utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic diagram of the structure of a full-spectrum inductively coupled plasma emission spectrometer based on a digital micromirror.

Fig. 2 is a structural schematic diagram of the ICP-AES dispersion detection device based on the digital micromirror of the present invention.

Figure 3 is a two-dimensional dispersion spectrum obtained on a digital micromirror after secondary transverse dispersion.

Detailed ways

As shown in Figure 1, the utility model relates to a novel inductively coupled plasma emission spectrometer based on a digital micromirror, comprising: a high-frequency generator 1, a torch tube 2, a sampling system 3, an external optical path 4, and a dispersion detection device 5; the argon gas in the torch tube 2 produces a plasma torch under the action of the high-frequency generator 1, and the sample to be tested enters the plasma torch through the sample introduction system 3, generates composite light under its excitation, and arrives through the external optical path 4 After the dispersion detection device 5, the composite light is decomposed into the emission spectrum of specific elements, and the light intensity signal is detected by the detector to obtain the spectrum.

As shown in Figure 2, the ICP-AES dispersion detection device based on the digital micromirror of the present utility model comprises: incident slit 7, collimating mirror, prism 9, step grating 10, the first condenser mirror, digital micromirror 12, the first Two converging mirrors and a photomultiplier tube 14; the collimating mirror adopts a concave reflector 8, and the first concentrating mirror and the second concentrating mirror are respectively a concave reflector 11 and a concave reflector 13. After the light emitted by the light source 6 passes through the incident slit 7, it is collimated by the concave reflector 8 and then enters the triangular prism 9, and the triangular prism 9 completes the primary lateral dispersion; Triangular prism 9 completes secondary transverse dispersion to form a two-dimensional spectrum; the light after triangular prism 9 secondary transverse dispersion is focused onto digital micromirror 12 surfaces through concave reflector 11, as shown in Figure 3; the light reflected by digital micromirror 12 passes through again The concave mirror 13 focuses on the photomultiplier tube 14 and is detected by the photomultiplier tube 14 . The scanning mode of the digital micromirror can be selected according to the detection requirements, such as full-spectrum scanning mode or single element scanning mode.

The collimating mirror and the first and second condenser mirrors are not limited to concave mirrors and convex lenses, and combined lenses can also be used.

Claims (3)

1. An ICP-AES dispersion detection device based on a digital micromirror, characterized in that it comprises an incident slit (7), a collimating mirror, a prism (9), an echelle grating (10), the first condenser mirror, and a digital micromirror (12), the second condenser, photomultiplier tube (14); after the incident light passes through the incident slit (7), it is collimated by the collimator and then incident on the triangular prism (9), and the initial transverse dispersion is completed by the triangular prism (9); The echelle grating (10) splits the light after the primary transverse dispersion, and then the secondary transverse dispersion is completed by the triangular prism (9) to form a two-dimensional spectrum; the light after the secondary transverse dispersion of the triangular prism (9) is focused by the first condenser lens to The surface of the digital micromirror (12); the light reflected by the digital micromirror (12) is focused to the photomultiplier tube (14) by the second condenser lens. 2. The ICP-AES dispersion detection device based on digital micromirror according to claim 1, characterized in that said collimating mirror can adopt a convex lens or a concave reflector. 3. The ICP-AES dispersion detection device based on digital micromirror according to claim 1, characterized in that said first condenser and second condenser adopt convex lens or concave reflector.