CN100516791C - Method and device for measuring intensity of UV. - Google Patents

Abstract

The invention relates to ultraviolet ray intensity detecting method and device. The method includes the following steps: collimating ultraviolet ray containing light by two rectangular diaphragms to form one way right parallel ray and reflect to grating; the first level optical spectrum of the reflected diffracted light is from ultraviolet ray, visible light, to infrared ray; the visible light and the infrared ray are turned back by one light filtering device; the ultraviolet ray is passed through and shot to ultraviolet luminescent material to give out fluorescent light; using electro-optical signal acquisition circuit includes photo detector to detect the fluorescent light intensity; converting to ultraviolet ray intensity. The invention can be used in sun ray ultraviolet ray detecting, varieties of ultraviolet light sources such as mercury lamp, xenon lamp, and deuterium lamp, and hollow cathode lamp measuring. It has the advantages of compact design, simple using, convenient carrying, and wide detecting range.

Description

Ultraviolet ray intensity detecting method and device

Technical field

The present invention relates to photoelectric detection technology field, particularly ultraviolet ray intensity detecting method and device.

Technical background

People's activities usually is exposed to solar ultraviolet and (under the radiation of 200nm～380nm), detects the power of daylight middle-ultraviolet lamp in real time, help preventing the generation of cutaneous lesions and relevant disease, help arranging production, work and live.In addition, in environmental monitoring, fire detection, outer space radiation detection, the analysis of biological and chemical ultraviolet light, the measurement of medical ultraviolet light and scientific research, all need ultraviolet ray intensity is detected.

Photoelectric devices such as common photoelectric pond and photodiode are not suitable for directly solar ultraviolet being detected; Though and photomultiplier can be used for ultraviolet detection, its volume is bigger, and adopts the high-voltage power supply power supply of high stability, and power consumption is big, uses inconvenient; Optothermal detector is lower to the responsiveness of ultraviolet light, is difficult to detect weak ultraviolet ray, and is difficult for practicability.

What the nearly more than ten years grew up is that the ultraviolet light detector of material still has certain response at visible light with GaP, GaAsP, SiC and TiO2 etc., and the ultraviolet response wave band immobilizes.At 190～680nm, peak value is at the 610nm place as the spectral response range of G12119, G1126 ultraviolet-ray diode.Therefore, usually add filter glass in its front, this can cause the reduction of ultraviolet detector sensitivity.

Summary of the invention

The objective of the invention is defective, a kind of optical grating diffraction beam split fluorescence ultraviolet ray intensity detecting method is provided at the prior art existence.

Another object of the present invention is to provide a kind of uitraviolet intensity pick-up unit.

Ultraviolet ray intensity detecting method of the present invention, comprise: contain ultraviolet light through two rectangular apertures collimation after, the quasi-parallel light that forms a branch of single direction incides on the reflection grating, the primary spectrum of the diffraction light of reflection is to ultrared band from ultraviolet ray, visible light, visible light and infrared ray are blocked by a filtering apparatus, and thereby ultraviolet being mapped to by this filtering apparatus sent fluorescence on the ultraviolet fluorescent material, come fluorescence intensity by an electrooptical signal collection circuit that comprises photodetector, then fluorescence intensity is converted to ultraviolet intensity.

Described rectangular aperture is the rectangular aperture of variable-width, and parallel placement.

Described reflection grating is plane reflection grating or concave reflection grating.

Described filtering apparatus is wide wide slit arrangement or the optical filter of slit arrangement, variable seam of fixing seam.

Described photodetector is photoelectric cell or photodiode.

As the further preferred embodiment of the inventive method, contain ultraviolet light and just enter diaphragm after through a slice or multi-disc decay glass.

Uitraviolet intensity pick-up unit of the present invention comprises a casing, and described casing is close lighttight, and interior is a black; One opening is arranged at casing top, fixes the sleeve of a rectangular aperture of respectively placing at two ends on the opening, and there is a decay bar the top of sleeve, can place monolithic or multi-disc decay glass in the seat; The casing inner bottom part has a wedge shape support, place a reflection grating on the described wedge shape support, described reflection grating is below sleeve, light through secondary diaphragm in the sleeve just in time can directly be injected reflection grating, on the first-order diffraction band, place the slit arrangement that variable seam is wide, there is a transparent substrate that scribbles ultraviolet fluorescent material described slit back, there is a photodetector described substrate back, described photodetector is electrically connected amplifying circuit, amplifying circuit is electrically connected an A/D convertor circuit, also comprise an one-chip computer module and a display screen, described one-chip computer module is electrically connected A/D convertor circuit, and one-chip computer module is handled the data that collect and obtained testing result, and testing result is shown by display screen, one side of casing has an opening that cooperates with display screen, and display screen is fixed on this opening part.

Described rectangular aperture is the rectangular aperture of variable-width, and its light hurdle width can be finely tuned in 1～3mm scope; The seam of the slit arrangement that described variable seam is wide is wide can finely tune in 0.1～2mm;

Described ultraviolet fluorescent material is low pressure mercury lamp fluorescent powder, three-basic-colour lamp fluorescent powder, lampion fluorescent powder or e-Pointer ink;

Described photodetector is photoelectric cell or photodiode; Described display screen is LED display or LCD display.

The present invention mainly adopts the reflection grating beam split, selects the ultraviolet light of corresponding ultraviolet band by light filter or slit, and it is mapped on the fluorescent material, sends visible light, changes into electric signal by devices such as normal optical battery or photodiodes.Realize that by amplifying circuit, A/D convertor circuit and single-chip microcomputer and LCD the output of data processing and light intensity shows at last.

The detection principle light path of ultraviolet light as shown in Figure 1, sunshine is the incidence reflection grating behind the secondary light hurdle, occurs the multiple order spectrum band behind its diffraction, the deflection of diffraction light is determined by grating equation.

According to grating equation:

d(sinα-sinβ)＝kλ (1)

D is a grating constant in the formula, and λ is the wavelength of light wave, and k is a diffraction progression, and α and β are respectively the angle of incident beam and diffracted beam and grating planar normal, β and α at the homonymy of normal for just, with α at the not homonymy of normal for negative.

Do not consider negative sign, (1) formula is differentiated:

dcosβΔβ＝kΔλ (2)

This is the relation that diffraction light wavelength coverage and angle of diffraction change, and establishing slit width is s, with the distance of grating be D, if β is hour, (2) formula becomes:

$\mathrm{\Δ\λ}=\frac{d}{k}\mathrm{\Δ\β}---\left(3\right)$

Then the ultraviolet spectral range by slit is:

$\mathrm{\Δ\λ}\≈\frac{d}{k}\frac{s}{D}---\left(4\right)$

Because the diffraction light energy mainly concentrates on first-order diffraction, i.e. k=1.Only consider primary spectrum, regulate different s and D, just can be by different spectral ranges, this is one of principal element of decision ultraviolet light detector spectral response, also is design detector light path and the main theory foundation of selecting grating.

Reflection grating is the light splitting part of detector key, can adopt glass or PVC material film plating, metal delineation or holographic technique method to make.When the design grating, should control its blazed wavelength and drop between 200～380nm, help improving the diffraction efficiency of ultraviolet diffraction light.If select concave reflection grating, slit should place the focal length place of concave grating; For less demanding occasion,, also can select for use CD, VCD, DVD CD as reflection grating as the physical optics instruments used for education.

Select only ultraviolet light to be produced the fluorescent material of visible light, as low pressure mercury lamp fluorescent powder, three-basic-colour lamp fluorescent powder, lampion fluorescent powder and e-Pointer ink etc., make ultraviolet light be converted into visible light by slit, the spectral range of its fluorescence and the spectral response curve of photodetector are complementary, to obtain higher photoelectric transformation efficiency.The coating thickness of fluorescent material be several micron to tens microns, be foundation with the fluorescence efficiency, selects suitable thickness, manufacturing process or process can adopt the mode of spraying, direct coating, plated film or sintering.Substrate is glass or transparent plastic sheet (as PVC etc.).

Photodetector needs planar package, its sensitive surface or size are bigger than the width of slit, be convenient to change slit width, minimizing is to the selectivity of incident light direction, the output photosignal is given A/D convertor circuit through the I-V conversion with after amplifying, carry out data sampling and processing by one chip microcomputer again, show by LED or LCD display at last.

In order to enlarge the ultraviolet ionization meter scope of measuring, not only adopt the electron gear shifting switch, and be provided with the optics gearshift, promptly added the ultraviolet light decay glass sheet of one or more known attenuation coefficient before sunshine enters secondary rectangular light hurdle, actual ultraviolet ray intensity is that instrument readings is divided by attenuation coefficient.Therefore, this method and pick-up unit are applicable to that not only stronger solar ultraviolet detects, and can be used for various ultraviolet sources, as the measurement of mercury lamp, xenon lamp and deuterium lamp and hollow cathode lamp.

The light path of pick-up unit and circuit module all are contained in a close lighttight can or the plastic casing, and inside and outside wall and adjusting support unit be painted black all, to reduce the interference and the influence of inner and extraneous parasitic light.

Compared with prior art, the present invention has following advantage and effect:

(1) spectral response range of this detector can artificially regulate or set, to adapt to different application scenarios and condition;

(2) this detector has higher UV detection sensitivity, and minimum detection intensity is 1 μ w;

(3) have optics gear shift function, it is bigger to detect the uitraviolet intensity scope, reaches more than the 500mw.

(4) stronger directivity is arranged, be subjected to the ambient visible light radiation interference little.

(5) this detector is compact to design, uses simply, is easy to carry, and cost is lower.

Description of drawings

Fig. 1 is the light path principle figure of the inventive method and device.Among the figure: RGB represents redness, and Green represents green, and Blue represents blueness;

Fig. 2 is the block scheme that adopts the course of work of the inventive method.

Fig. 3 is a kind of embodiment structural representation of pick-up unit of the present invention.

Embodiment

As shown in Figure 1, 2, contain ultraviolet light through after forming the optical filtering collimator apparatus by the secondary rectangular aperture of front and back straight line parallel arrangement, the quasi-parallel light that forms a branch of single direction incides on the reflection grating, and one section band from ultraviolet, visible light to infrared light appears in the diffraction light of reflection.Place a slit or a light filter that variable seam is wide in position, the printing opacity direction of slit is parallel with the spectrum line direction, unwanted visible light of elimination and infrared light, select corresponding ultraviolet light, again by behind the transparent substrate that scribbles ultraviolet fluorescent material, detect by photodetectors such as normal optical battery or photodiodes, calculate ultraviolet intensity and export the result by single-chip microcomputer behind the output process amplifying circuit of photodetector and the A/D convertor circuit by display screen.

As shown in Figure 3,1 is sleeve, and 2,3 is rectangular aperture, and the printing opacity direction is parallel to each other, and adopts metal material to make, and its diaphragm width can be finely tuned in 1～3mm scope.11 are the decay bar, and 12 are decay glass, can place the clear glass or the coloured glass of monolithic or multi-disc known attenuation coefficient in the decay bar.4 is reflection grating, can be plane reflection grating or concave reflection grating, and 15 is the wedge shape support, is used for fixing reflection grating.5 is slit arrangement, stitches wide can the fine setting in 0.1～2mm.6 is fluorescent material and substrate, and 7 is photodetector, can be photoelectric cell or photodiode, and slit arrangement 5, fluorescence substrate 6 and photoelectric cell 7 are together curable, have the integral position regulatory function.8 is amplifying circuit, and 9 is A/D convertor circuit and one-chip computer module, and 10 is display screen, and 13 is the pick-up unit casing, and 14 is holding nut, mainly cooperates the tripod of camera to use design, is convenient to fixed test instrument and adjusting and follows the tracks of sun direction of light.The surperficial painted black of all parts in the detector is to reduce the influence of box reflects light and scattered light.

Claims (4)

1, a kind of uitraviolet intensity pick-up unit is characterized in that: comprise a casing, described casing is close lighttight, and interior is a black; First opening is arranged at casing top, fixes a sleeve of respectively placing a rectangular aperture at two ends on first opening, and there is a decay bar the top of sleeve, places monolithic or multi-disc decay glass in the seat; The casing inner bottom part has a wedge shape support, place a reflection grating on the described wedge shape support, described reflection grating is below sleeve, light through secondary diaphragm in the sleeve just in time can directly be injected reflection grating, on the first-order diffraction band, place the slit arrangement that variable seam is wide, there is a transparent substrate that scribbles ultraviolet fluorescent material described slit back, there is a photodetector described substrate back, described photodetector is electrically connected amplifying circuit, amplifying circuit is electrically connected an A/D convertor circuit, also comprise an one-chip computer module and a display screen, described one-chip computer module is electrically connected A/D convertor circuit, and one-chip computer module is handled the data that collect and obtained testing result, and testing result is shown by display screen, one side of casing has second opening that cooperates with display screen, and display screen is fixed on this second opening part.

2, device according to claim 1 is characterized in that described rectangular aperture is the rectangular aperture of variable-width, and its light hurdle width can be finely tuned in 1～3mm scope; The seam of the slit arrangement that described variable seam is wide is wide can finely tune in 0.1～2mm.

3, device according to claim 1 and 2 is characterized in that described ultraviolet fluorescent material is low pressure mercury lamp fluorescent powder, three-basic-colour lamp fluorescent powder, lampion fluorescent powder or e-Pointer ink.

4, device according to claim 3 is characterized in that described photodetector is photoelectric cell or photodiode; Described display screen is LED display or LCD display.

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