CN2195091Y

CN2195091Y - Portable high-resolution laser granulometer

Info

Publication number: CN2195091Y
Application number: CN 94225544
Authority: CN
Inventors: 任仲京
Original assignee: SHANDONG BUILDING MATERIALS INDUSTRIAL COLLEGE
Current assignee: SHANDONG BUILDING MATERIALS INDUSTRIAL COLLEGE
Priority date: 1994-01-11
Filing date: 1994-01-11
Publication date: 1995-04-19
Anticipated expiration: 2004-01-11

Abstract

The utility model discloses a portable high-resolution laser granulometer, comprising a laser, a plane mirror, a light beam extending lens, a pinhole filter, a Fourier transformation lens, an array photodetector, an L-form optics guide rail, and a transparent sample-plate or a current sample cell. The utility model adopts the Fourier transformation lens with reduced focal distance and aperture to change the traditional parallel light road into the divergent and convergent light road. The transparent sample or the current sample cell is provided between the Fourier transformation lens and the array photodetector and its position can be accommodated according to the requirement. The measuring range of the utility model is adjustable without replacing Fourier lens. The bulk of the utility model is small, the weight is light, the carrying is convenient, and the stage division number of the coarseness increases so that the resolution is improved.

Description

Portable high-resolution laser granulometer

The utility model relates to optical instrument and powder body examination examination technical field.

The semi-manufacture or the product in many commercial production field are powdered usually, and it is one of parameter the most basic in the production control that the grain graininess of powder is formed.The test of granularity and distribution thereof is important test event in production and the scientific research.Method of testing at present commonly used has sedimentation, sieve formula, microscopic method and laser particle size analysis method, wherein fast, the good reproducibility of latter's test speed, applied range, and can be used to produce online test, cause people's attention just gradually.

But there are more following problems in present laser particle analyzer both domestic and external, influences applying of it.

(1), adopt parallel light path, optical path length is paid a upright leaf lens front and is established collimating mirror, measuring samples places pays between upright leaf lens and the collimating mirror.Thereby volume is big, and is not portable;

(2), the measuring samples stationkeeping, change measurement range and need change the Fourier transformation lens, and adjust light path, use inconvenience;

(3), resolution is low, common laser particle analyzer only divides 32 fixing grades at most in measurement range, can not satisfy some occasion higher to resolution requirement;

(4), cost an arm and a leg, common enterprise is difficult to accept.

The purpose of this utility model provide a kind of volume little, in light weight, be easy to carry, measurement range is adjustable, resolution is higher, the new pattern laser particle size analyzer that price is lower is in order to promoting the popularization use at production scientific research first line.

Accompanying drawing 1 is a light channel structure synoptic diagram of the present utility model;

Accompanying drawing 2 is portable outside drawings of one of the utility model enforcement.

Below in conjunction with accompanying drawing design of the present utility model is described in detail:

In the accompanying drawing 1: 1 is helium-neon laser or semiconductor laser, 2,3 is plane mirror, 4 is beam expanding lens, 5 is pinhole filter, 6 is the Fourier transformation lens, and 7 is array photodetectors, and 8 is L type optics guide rail, 9 is transparent sample plate or mobile sample cell, one of 9 other positions that may place for transparent sample plate or mobile sample cell.

Laser instrument 1,

catoptron

2 and 3, beam expanding lens 4, pinhole filter 5, Fourier transformation lens 6, with array photodetectors 7, be fixed on the optics guide rail 8 by special stand, the long 600mm of optics guide rail, pay between upright leaf lens 6 and the photodetector 7 60～300mm apart, transparent sample plate 9 can be along the optical axis direction adjusting position in this scope.The focal length of paying upright leaf lens 6 and aperture are than traditional all having reduced, and focal length is 90～110mm, and the aperture is 35～50mm, and its major function is the center that pinhole filter 5 is imaged on array photodetectors 7.Pinhole filter 5 to the distance of Fourier transformation lens 6 is decided by the focal length size of paying upright leaf lens 6.

The light that laser instrument 1 sends is by after

plane mirror

2 and 3 reflections, becomes through beam expanding lens 4 and pinhole filter 5 and disperses light path and directly arrive and pay upright leaf lens 6, by paying upright leaf lens 6 light is transformed to arrival array photodetectors 7 behind the converging beam.Transparent sample plate or mobile sample cell 9 place and pay between upright leaf lens 6 and the photodetection 7 and can move along optical axis direction, and can accurately locate.Need not to change and pay upright leaf lens 6, also needn't readjust light path, can change the granulometry scope by the position that changes sample panel 9.

For example, sample panel is placed on 9 ' locate littler than being placed on 9 place's measurement ranges because the diffracted ray aperture angle that sample panel the closer to photodetector 7, receives is big more, the frequency band that can survey is also wide more, according to paying upright leaf optical principle: the bulk that the frequency band of broad is corresponding less.Therefore, sample panel is positioned at 9 ' and 9 o'clock detectable particle diameters are little than being positioned at, and corresponding measurement range narrows down, and broadens otherwise then measure.Change measurement range with this method, do not need conversion to pay upright leaf lens, can expand the scope of 0.6～400um by 0.6～60um to.

Measurement range is wide, is applicable to the uneven particle swarm of grain size.Measurement range is narrow, then is applicable to the occasion higher to resolution requirement.Because at photodetector endless belt number one regularly, gradation progression is also certain, measurement range narrows down, and mean that each particle size fraction is also corresponding to narrow down, so the resolution of instrument is with regard to corresponding improve.

The utility model can adopt single entry mensuration or compound mensuration as required, and the single entry mensuration is identical with the measuring method of other laser particle analyzer, no longer describes in detail.Compound mensuration is that the sample panel that will be loaded with same particle swarm for example places on 9 and 9 ' two diverse locations successively, records two groups of data respectively, carries out inverting by special purpose computer, tries to achieve the size-grade distribution of particle swarm.More than operation is equivalent to improve spectrum face sampling density under the prerequisite that does not change photodetector 7 structural parameters and measurement range, thereby makes the branch progression of instrument increase nearly one times, so the resolution of instrument has also correspondingly improved.

Data processing of the present utility model adopts special-purpose single-chip microcomputer, and LCDs and mini-printer replace multi-purpose computer, to reduce the instrument volume, reduces cost.

In the accompanying drawing 2: K is an operating key, and H is an air hole, and S is a LCDs, and P is a printer, and M is a sampling gate.Whole instrument 600 * 400 * 180mm ³, can put into the medium size suitcase.

The use step is as follows: earlier by first operating key, with energized; Again by second operating key: measure agranular empty background; Open sampling gate M then, the transparent sample plate that is loaded with particle is inserted special stand, push sampling gate; Press the 3rd operating key, the instrument measurement line data of going forward side by side is handled, and result is presented on the LCDs S; Press the 4th operating key, mini-printer P can print off the measurement result data, and instrument recovers armed state.Instrumentation is only used four keys, and is easy to learn.When moved the sample panel position, displacement data if use the sample cell that flows, started sample ebullator (not within the utility model scope) by the automatic record of single-chip microcomputer when then operating.

The utility model has the advantages that volume is little, in light weight, can be designed to as required multiple portable mode, be convenient for carrying; The apparatus measures scope is adjustable, need not change and pay vertical leaf lens; The grading number increases, and has improved resolution ratio; Simple to operate, cheap.

Claims

1, a kind of portable high-resolution laser particle size analyzer, its structure is formed and is comprised laser instrument, plane mirror, beam expanding lens, pinhole filter, the Fourier transformation lens, array photodetectors, L type optics guide rail, transparent sample plate or mobile sample cell, wherein laser instrument, plane mirror, beam expanding lens, pinhole filter, Fourier transformation lens, array photodetectors are fixed on the optics guide rail with special stand, from the Fourier transformation lens to the light path between the photodetector for converging light path; The Fourier transformation focal length of lens that is adopted that is characterised in that of the present utility model is 90～110mm, the aperture is 35～50mm, from pinhole filter to the light path between the Fourier transformation lens for dispersing light path, transparent sample plate or mobile sample cell place converging on the light path between Fourier transformation lens and the array photodetectors, can move along optical axis direction, can accurately locate.

2, laser particle analyzer as claimed in claim 1 is characterized in that between Fourier transformation lens and the photodetector being 60～300mm apart.