CN103630497A

CN103630497A - Movable type reference beam device used for water quality analyzer

Info

Publication number: CN103630497A
Application number: CN201210297353.3A
Authority: CN
Inventors: 李宏; 吴铁军
Original assignee: HANGZHOU SIGMARO ELECTRO-OPTICAL TECHNOLOGY Co Ltd
Current assignee: HANGZHOU SIGMARO ELECTRO-OPTICAL TECHNOLOGY Co Ltd
Priority date: 2012-08-21
Filing date: 2012-08-21
Publication date: 2014-03-12

Abstract

The invention discloses a movable type reference beam device used for a water quality analyzer and used for eliminating measuring errors due to instrument photoelectric device performance drifts. The device comprises a movable type double-groove sample cell 1, a sample cell driving device 2 composed of a driving motor 11, a rack 12 and a driving gear 13, a data processing and controlling unit 3, and a sample detection light path composed of a light source 4, light fibers 5, a light source incidence window 6, a spectrum detection window 7 and a photosensitive sensor 8. During a sample detecting process, the data processing and controlling unit 3 sends an instruction, so that the double-groove sample cell 1 is driven by the sample cell driving device 2 to move along a sliding groove 15 arranged on a sample cell base 14 to and fro; a pure water reference groove 10 and a sample cell to be detected 9 are sequentially located on the sample detection light path; and pure water reference spectrum and sample to be detected spectrum are generated and are sent to the data processing and controlling unit 3 for calculation, so that effective spectrum signals of specific compound in the water sample to be detected are obtained.

Description

A kind of portable reference light paths device for water quality analyzing instrument

Technical field

The present invention relates to a kind of reference light paths device, particularly a kind of light path reference instrument for water quality optical analysis instrument.

Background technology

Described water quality optical analysis instrument is widely used in measuring the concentration of specific compound in water body (being generally organism), its working mechanism is while utilizing the continuous spectrum light beam irradiates water body of ultraviolet-visible (UV) wave band (200-800nm), its energy can be by the principle that wherein various organic molecule selectivity absorb, by measuring UV absorption spectrum intensity, fluorescent emission intensity or the Raman diffused light spectral intensity of water sample, then obtain the measured value of organism overall target in water sample by complicated calculated with mathematical model.In the measurement mechanism of this principle of work, except light source, light sensor, outside the physical optics checkout equipments such as water sample sampling device and embedded computer data processing unit, all chemical reaction processes have been got rid of, therefore no longer need any chemical reaction equipment, thereby a series of defects of traditional hydrochemistry analysis meter have been overcome from performance, there is analysis speed fast (being generally the 100min order of magnitude), without reagent (and the reagent that may bring discharges the secondary environmental pollution causing), device structure is simple, non-maintaining, it is lower that equipment is installed the environmental requirement of required place, equipment construction investment and cost of equipment maintenance be lower advantage all, thereby be specially adapted to unattended online water analysis on a large scale, environmental pollution monitoring.Chinese invention patent CN101275905A < < multi-source optical spectrum syncretizing portable water quality analysis meter > > has provided a representative instance of this type of water quality optical analysis instrument.

In the use procedure of this type of instrument, the performance drift of photoelectric device is (if instrument light source is with extending and luminous intensity decay service time, and the baseline wander that produces due to temperature variation in the course of the work of light sensor), be the main interference factors that causes instrument measurement precise decreasing.Therefore, how reducing and to eliminate the measuring error causing due to above-mentioned disturbing factor, is one of gordian technique guaranteeing the measuring accuracy of water quality optical analysis instrument in long-term use procedure.

Mono-kind of the Chinese invention patent CN101539521A < < constant-temperature fluorescence detector > > with optical fiber reference light paths has provided a kind of reference light paths implementation method that adopts optical slot, light beam beam-splitting board and photomultiplier, to eliminate the instantaneous shake of light source and the interference of light intensity attenuation to testing result.But optical slot and light beam beam-splitting board all can significantly weaken the energy density of water sample incident light, cause the measurement result signal to noise ratio (S/N ratio) under weak signal conditions significantly to decline, as improving signal to noise ratio (S/N ratio), need need to adopt powerful light source; And be to amplify feeble signal to adopt photomultiplier, can not provide the spectral distribution curve of measurement result, photomultiplier cannot be eliminated by the method as light sensor baseline wander error in the course of the work in addition.Therefore there is limitation in said method.

Summary of the invention

The object of the invention is for the problem that prior art measure signal intensity when realizing reference light paths weakens too much, signal to noise ratio (S/N ratio) reduces, and a kind of new reference light paths structure is provided.Be characterized in adopting the portable sample cell design of double flute, in water sample measuring process, obtain successively water sample spectral signal and reference spectral signal, then by calculating, eliminate the interference of detected water sample incident intensity fluctuation to measurement result.The present invention is without obtaining reference signal by optical slot and light beam beam splitting stool optical device, at the performance drift of eliminating due to photoelectric device, cause measuring error time do not affect the signal to noise ratio (S/N ratio) of measurement result, and can be widely used in the obtaining of continuous spectrum distribution curve of water sample.

In existing water sample in the optical analysis process of organic concentration, for the interference to specific compound spectral effective signal in water sample of the spectrum of eliminating hydrone itself, conventionally all need before instrument operation, use pure water water sample to carry out " zero correction ", preserve the measure spectrum of this pure water water sample, so that in follow-up water sample spectral measurement process, by calculating, deduct the impact of pure water spectrum, obtain the efficient light spectrum signal of specific compound in water sample.

According to the above-mentioned working mechanism of water quality optical analysis instrument, technical scheme of the present invention is: by the sample cell part design of instrument, be double flute portable structure, one of them sample cell is used for depositing removable sample, and another sample behaviour is for depositing the permanent pure water reference sample of sealing up for safekeeping; Sample cell parts integral body can move reciprocatingly with respect to light source and light sensor by driven by power under controller instruction, successively sample and pure water reference sample is positioned on the optical measurement passage being comprised of light source and light sensor.

When water quality optical analysis instrument is carried out sample measurement at every turn, its inner controller first portable sample cell parts of instruction is positioned pure water reference sample on optical path, and obtains pure water reference spectrum; Then the portable sample cell parts of instruction are positioned sample for optical path, obtain detected water sample spectrum.Finally at above-mentioned spectrum, obtain on the basis of result, by calculating, deduct the impact of pure water spectrum, obtain the efficient light spectrum signal of specific compound in water sample.

While measuring due to instrument, the interval time of obtaining successively pure water reference spectrum and sample spectrum by portable sample cell is very short (conventionally 10 at every turn ^-1-10 ⁰therefore the s order of magnitude), the performance drift increment of the photoelectric devices such as the light source in interval during this time and light sensor can be considered as to zero.Thereby when passing through to calculate, while deducting the affecting of pure water spectrum from sample spectrum, therefore because pure water reference spectral measurement error and sample spectral measurement error that photoelectric device performance drift causes are cancelled each other, effectively reduce and eliminated the impact of photoelectric device performance drift on the efficient light spectrum signal of specific compound in water sample.

The present invention does not change the original photoelectric device type of water quality optical analysis instrument and spectrum generation mechanism when realizing, therefore when eliminating the affecting of photoelectric device performance drift, do not change the signal to noise ratio (S/N ratio) of specific compound efficient light spectrum signal in detected water sample, do not change specific compound efficient light spectrum signal type in the detected water sample of original photoelectric device type decided, therefore can be used for the photoelectric device performance drift error concealment of various water quality optical analysis instrument yet.

Accompanying drawing explanation

Fig. 1 is the portable reference light paths device of water quality analyzing instrument schematic diagram.

Fig. 2 is reference light paths device A-A cut-open view.

Embodiment

As shown in Figure 1 to Figure 2, a kind of portable reference light paths device for water quality analyzing instrument, by double flute sample cell 1, sample cell drive unit 2, data processing and control module 3, and the sample detection light path being comprised of light source 4, optical fiber 5, light source incidence window 6, spectral detection window 7 and light sensor 8 is formed.Wherein double flute sample cell 1 is comprised of sample groove 9 and pure water reference groove 10, places respectively sample and reference pure water sample; Sample cell drive unit 2 comprises drive motor 11, is connected to the tooth bar 12 of double flute sample cell 1 bottom and is connected to the driven wheel 13 in drive motor 11 rotating shafts.Sample detection light path and drive motor 11 are connected with sample cell pedestal 14, and double flute sample cell 1 can move back and forth along the chute 15 on sample cell pedestal 14 under the driving of sample cell drive unit 2.

When instrument starts a sample measurement process, first data processing and control module 3 send order-driven sample cell drive unit 2 the pure water reference groove 10 in double flute sample cell 1 are positioned in sample detection light path, and generate pure water reference spectrum; And then send order-driven sample cell drive unit 2 the sample groove 9 in double flute sample cell 1 is positioned in sample detection light path, and generate sample spectrum.The pure water reference spectral signal generating successively and sample spectral signal is finally admitted to data processing and control module 3 calculates, to obtain the efficient light spectrum signal of specific compound in detected water sample.

Claims

1. the light path reference instrument for water quality optical analysis instrument, by double flute sample cell 1, sample cell drive unit 2, data processing and control module 3, and sample detection light path forms, it is characterized in that double flute sample cell 1 is comprised of sample groove 9 and pure water reference groove 10, places respectively sample and reference pure water sample.

2. the light path reference instrument for water quality optical analysis instrument according to claim 1, is characterized in that double flute sample cell 1 can move back and forth along the chute 15 on sample cell pedestal 14 under the driving of sample cell drive unit 2.

3. the light path reference instrument for water quality optical analysis instrument according to claim 1, while it is characterized in that instrument starts a sample measurement process, data processing and control module 3 send order-driven sample cell drive unit 2 the pure water reference groove 10 in double flute sample cell 1 and sample groove 9 are positioned in sample detection light path successively, and corresponding generation pure water reference spectrum and sample spectrum, then send into data processing and control module 3 calculates, to obtain the efficient light spectrum signal of specific compound in detected water sample.