CN1023426C - Optical fibre transmission photo-electronic directly reading spectrograph - Google Patents

Abstract

The present invention relates to a photoelectric direct reading spectrometer for optical fiber transmission, which is composed of a dispersion system, a spectral line detection system and a signal amplifying and processing system. Spectral lines given by the dispersion system are respectively transmitted to the same optoelectronic receiver by optical fibers with the number of paths identical to the kind of measured elements in a detection system, the exposure time of the spectral lines is controlled by a shutter, and the measured elements and contents thereof are obtained by controlling the shutter by a computer and processing photoelectric signals. The present invention is a multi-way photoelectric direct reading spectrometer when a multi-way photoelectric receiver is adopted, and is a single channel photoelectric direct reading spectrometer when a single channel photoelectric receiver is adopted and shutters are appropriately added.

Description

Optical fibre transmission photo-electronic directly reading spectrograph

The invention belongs to spectral instrument.

Existing photo-electric direct reading spectrometer can be divided into two kinds of single track and multiple tracks.In the single track photo-electric direct reading spectrometer, the selection of element to be measured or determine to make the pairing spectral line of element be in that intensity that a certain fixed position goes out spectral line by a photoelectric receiver measuring realizes by the grating that rotates dispersion system.Therefore, it needs accurate rotating mechanism and control corresponding system.Even like this, yet exist wavelength repeatability and wavelength accuracy problem, so its measuring accuracy is not high.In the multiple tracks photo-electric direct reading spectrometer, employing be the simultaneously-measured methods of all spectral lines, need not rotating shutter, thereby do not have the wavelength repeatability problem, but it all needs the corresponding receiving system of a cover to each bar spectral line.Along with the increase of tested element, volume and cost sharply rise, thereby this instrument is just in the use of just having ready conditions of large enterprise and provincial analysis department.

The present invention designs a kind of single track photo-electric direct reading spectrometer that does not need rotating shutter for overcoming above-mentioned shortcoming, and grating rotates the shortcoming of bringing in the single track thereby can overcome.

But technical scheme of the present invention is the optical fiber that adopts with the identical way of kind of analytical element, arrange by spectral line pairing position on the spectrum face of known elements the position of its input end, make it respectively each the bar spectral line on the dispersion system spectrum face is transferred to same receiver and utilize shutter to select the time shutter of spectral line and control spectral line, handle the intensity that obtains each bar spectral line with computing machine at last, thereby determine pairing element and content thereof.

Below in conjunction with description of drawings concrete structure of the present invention.The present invention is an Optical Fiber Transmission single track direct-reading spectrometer, and mainly by dispersion system (the empty frame A of Fig. 1), spectral line detection system (empty frame B) and signal amplify with disposal system (empty frame M) to be formed.Dispersion system adopts the polychromator structure, mainly by condenser lens A ₁, entrance slit A ₂, catoptron A ₃With grating A ₄Form, and grating A is fixed, it will be arranged and the contained element of measured matter spectrum line one to one from providing on spectrum face E after the optical dispersion of measured matter by wavelength.The spectral line detection system is mainly by exit slit (B _1-1, B _1-2..., B _1-N), have incident end (B _2-1, B _2-2..., B _2-N) and exit end B ₃Optical fiber, projection objective B ₄, photelectric receiver B ₅And power supply B ₆Form.Wherein exit slit is positioned at the spectrum face E that dispersion system provides and goes up corresponding with each bar spectral line of analyzed element; The shape of optical fiber input end and position are corresponding one by one with exit slit, by optical fiber the emergent light of slit are transferred to projection objective B respectively ₄Be projected to photelectric receiver B again ₅On, if photelectric receiver also can be exported enough strong signal and when not influencing measuring accuracy, can omit projection objective at this moment, and directly transmit spectral line to photelectric receiver 5 by optical fiber when projection objective omits.And by photelectric receiver 5 output signals, again through the circuit M in signal amplification and the disposal system ₁Send into computing machine M after amplification, sampling, maintenance and the A/D conversion ₂Handle.The operator imports some necessary parameter (as element to be measured and time shutter etc.) by the keyboard of this computing machine, shutter control system M then, promptly control shutter and make its work, The ultimate results can be presented on the screen of computing machine also can be come out by printer prints.Photelectric receiver B ₅Be single track receiver (for example photomultiplier etc.), because same photelectric receiver need receive the different spectral lines that all Optical Fiber Transmission are come, so at exit slit (B _1-1, B _1-2..., B _1-N) before or after, or at projection objective B ₄Before or after set up shutter (B among Fig. 1 _0-1, B _0-2..., B _0-NOr B among Fig. 2 and Fig. 3 ₀), the passage that utilizes computer control to open each spectral line with time-sharing procedure during measurement makes photelectric receiver B ₅Receive the spectral line on the spectrum face E successively or open the transmission channel of a certain spectral line as required and close the transmission channel of all the other all spectral lines, the opening time of shutter this moment is exactly the time shutter of spectral signal on photelectric receiver, the shape of this shutter and working method system decide according to the shape of the optical fiber end that matches with it, as Fig. 1 is that shutter is set up the structure before exit slit, this moment, optic fibre input end was arranged as the shape of slit that matches with it, so adopt the discrete shutter (B among Fig. 1 that is complementary with slit _0-1, B _0-2..., B _0-N), also can adopt slit along the portable shutter of spectrum face; Fig. 2 and Fig. 3 are that shutter is set up the structure after fiber-optic output.The output terminal B of each road optical fiber among Fig. 2 ₃Gather point-blank, so adopt single hole or the portable shutter B of slit ₀The output terminal B of each road optical fiber among Fig. 3 ₃Be integrated on the circumference, so adopt the disk that has single hole or opening around the rotary type shutter B of this circle center ₀

The present invention has two major advantages: (1) is owing to adopt optical fiber and shutter respectively each bar spectral line to be transferred to photelectric receiver successively, so the grating of dispersion system is fixed, therefore each wavelength repeatability of measuring is fabulous, light path and simple in structure, good reliability; (2) be easy to realize automatic measurement, reduce labor intensity of operating personnel, the fast time of measuring speed is short.

Under regard to accompanying drawing and describe.

Accompanying drawing the 1,2, the 3rd, structure of the present invention.Fig. 1 is at exit slit (B _1-1, B _1-2..., B _1-N) dispose shutter (B before _0-1, B _0-2..., B _0-N) structure.During measurement, by computing machine (M among Fig. 1 ₂) by shutter control system M ₃Make shutter carry out work according to required time.Fig. 2 and Fig. 3 are at projection objective B ₄Dispose shutter B before ₀Structure.The output terminal B of optical fiber among Fig. 2 ₃Gather point-blank, so adopt a thin plate with holes as shutter B ₀, and by shutter control system M ₃Control, it is moved along this straight line select different spectral lines to expose.The output terminal B of optical fiber among Fig. 3 ₃Be integrated on the circumference, so adopt a disk with holes as shutter B ₀, and by shutter control system M ₃Control, its center around this circumference is rotated select different spectral lines to expose.

Most preferred embodiment of the present invention is the grating A of dispersion system ₄Adopt the concave surface replica grating.Adopt photomultiplier as photelectric receiver.The output terminal of optical fiber is integrated on the circumference (Fig. 3), adopts a disk with holes as shutter its center around this circumference to be rotated and reaches the purpose of selecting the spectral line exposure.

Claims (5)

1, a kind of optical fibre transmission photo-electronic directly reading spectrograph is mainly by condenser lens [A ₁], entrance slit [A ₂], catoptron [A ₃] and grating [A ₄] dispersion system [A] formed, exit slit [B _1-1, B _1-2..., B _1-N], have incident end [B _2-1, B _2-2..., B _2-N] and exit end [B ₃] multi-channel optical fibre, projecting lens [B ₄], photelectric receiver [B ₅] and power supply [B ₆] the spectral line detection system [B] formed and signal amplification, sampling, A/D translation circuit [M ₁], computing machine [M ₂] and shutter control system [M ₃] signal formed amplifies with disposal system [M] and form, and it is characterized in that the grating [A of dispersion system ₆] be fixed; Exit slit [B _1-1, B _1-2..., B _1-N] be positioned at spectrum face [E] and go up corresponding with each bar spectral line of analyzed element; Optical fiber input end [B _2-1, B _2-2..., B _2-N] shape and position and exit slit [B _1-1, B _1-2..., B _1-N] corresponding one by one, these optical fiber transfer to projection objective [B with the emergent light of slit ₄]; Photelectric receiver [B ₅] be the single track photelectric receiver, simultaneously at exit slit [B _1-1, B _1-2..., B _1-N] set up shutter [B before _0-1, B _0-2... B _0-N] by computing machine [M ₂] by shutter control system [M ₃] control shutter time shutter, make each bar spectral line enter photelectric receiver [B successively ₅].

2, according to the described optical fibre transmission photo-electronic directly reading spectrograph of claim 1, it is characterized in that shutter [B _0-1, B _0-2..., B _0-N] can adopt the thin plate movable type of with holes or slit, also can adopt the disk rotary type of with holes or opening.

3, according to the described optical fibre transmission photo-electronic directly reading spectrograph of claim 1, it is characterized in that: as photelectric receiver [B ₅] output signal enough strong, remove projection objective [B ₄] when not influencing measuring accuracy yet, projection objective [B ₄] just can omit, and the output terminal of optical fiber and photelectric receiver directly are coupled.

4, according to the described optical fibre transmission photo-electronic directly reading spectrograph of claim 1, it is characterized in that shutter [B _0-1, B _0-2..., B _0-N] also can be placed on exit slit [B _1-1, B _1-2..., B _1-N] and the incident end [B of optical fiber _2-1, B _2-2..., B _2-N] between.

5,, it is characterized in that the portable shutter of thin plate of with holes or slit and the disk rotary type shutter of with holes or opening also can be placed in projection objective [B according to claim 1 or the described optical fibre transmission photo-electronic directly reading spectrograph of claim 2 ₄] and the output terminal [B of optical fiber ₃] between.

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