CN106199033A - A kind of high accuracy sample injection method - Google Patents

Abstract

The invention discloses a kind of high accuracy sample injection method, photoelectric metering formula sample introduction based on water quality on-line monitoring instrument, first pass through water quality on-line monitoring instrument control sample introduction liquid level and exceed photoelectric metering position, control sample introduction liquid level by water quality on-line monitoring instrument again and return at a slow speed photoelectric metering position, photosignal waveform variation characteristic when exceeding photoelectric metering position according to sample introduction liquid and return photoelectric metering position, rule of thumb preset ratio A, there is corresponding relation in this ratio A and liquid level, thus can accurately detect and control liquid level and arrive this fixing position, reach accurate measurement and improve the purpose of measurement reproducibility.It has the beneficial effect that and water quality on-line monitoring instrument sample introduction precision, the measurement accuracy of increase water quality on-line computing model and measurement reproducibility is greatly improved.It is more suitable for the application scenario of high chroma and high concentrtion simultaneously.

Description

A kind of high accuracy sample injection method

Technical field

The present invention relates to monitoring water quality on line field, be specially a kind of high accuracy sample injection method.

Background technology

Water sample and the reagent input mode of water quality on-line monitoring instrument are broadly divided into quantitative plunger displacement pump and photoelectric metering etc. Mode.With quantitative plunger displacement pump sample introduction precision is higher but manufacturing cost and maintenance cost are high.The low cost of photoelectric metering mode, can High by property.Owing to photoelectric metering is usually taken the change of photoelectric signal during liquid level arrival photoelectric metering position more than a set amount Time, it is identified as sample introduction liquid level and arrives photoelectric metering position, when colourity, turbidity or the proportion of liquid change, photosignal becomes There is not fixed relationship in change amount and liquid level position, thus measuring accuracy and repeatability are poor, even when colourity and the turbidity of water sample Time higher, the change of photoelectric signal amount does not reaches the variable quantity of setting, causes None-identified to measure.

Concrete method is as follows: during infrared electro metering, and metering position is actually a region, and liquid level arrives this region Time, the photosignal of reception i.e. starts change.Determine that a concrete liquid level is as final metering position, the commonly side of metering Method is, photosignal during the empty gauge line of detection, is such as H0, assumes when photosignal increases 50%(), or photosignal increase During one fixed value, then it is judged as that liquid level arrives metering position.It practice, when the turbidity of liquid is different with colourity, work as optical telecommunications During number same increase 50% or same when increasing a fixed value, corresponding liquid level is the most different, therefore the method measuring accuracy Low.Even after the turbidity of liquid or colourity are more than certain value, when liquid level exceedes metering position, photosignal increasing degree reaches at all Assume less than 50%() or the fixed value of setting, cause and cannot measure.

Send out for improving the precision of photoelectric metering and make water quality monitor obtain more preferable certainty of measurement and measurement reproducibility Bright a kind of high accuracy sample injection method.

Summary of the invention

It is an object of the invention to provide a kind of water quality on-line monitoring instrument high accuracy sample injection method, to solve prior art existence The problem that measuring accuracy is poor.

In order to achieve the above object, the technical solution adopted in the present invention is:

A kind of high accuracy sample injection method, it is characterised in that: photoelectric metering formula sample introduction based on water quality on-line monitoring instrument, first pass through Water quality on-line monitoring instrument controls sample introduction liquid level and exceedes photoelectric metering position, then controls sample introduction liquid level at a slow speed by water quality on-line monitoring instrument Return photoelectric metering position, photosignal waveform change when exceeding photoelectric metering position according to sample introduction liquid and return photoelectric metering position There is corresponding relation in feature, rule of thumb preset ratio A, this ratio A and liquid level, thus can accurately detect and control liquid level Arrive this fixing position, reach accurate measurement and improve the purpose of measurement reproducibility.

A kind of high accuracy sample injection method, it is characterised in that: exceed photoelectric metering position according to sample introduction liquid and return photoelectrometer Photosignal data variation feature during amount position, sets out ratio value A the most in advance, further determines that accurately according to ratio value A Metering liquid level position, process is as follows:

During sample introduction, when sample introduction liquid level rises towards from H0 and reaches near photoelectric metering position, due to liquid turbidity, colourity and Refractive index affects, and the photosignal data received significantly change；Height H1, light is arrived when sample introduction liquid level exceedes photoelectric metering position Electrical signal data no longer changes；When sample introduction liquid level returns at a slow speed photoelectric metering position, photosignal data change again；Root Photosignal waveform variation characteristic when exceeding photoelectric metering position according to sample introduction liquid and return photoelectric metering position, calculates ratio value A；When sample introduction liquid level returns A*(H1-H0) time, i.e. sample introduction liquid level arrives accurate photoelectric metering position.

A kind of high accuracy sample injection method, it is characterised in that: described water quality on-line monitoring instrument is built with control feed liquor and moves back The automatic control module of liquid speed, and data processing module.

The advantage of the inventive method:

Automatically control and data processing module it is contemplated that water quality on-line monitoring instrument builds, by controlling input mode and speed Degree, automatically identifies the change of photoelectric signal feature, and then accurately judges photoelectric metering position, improve sample introduction precision, finally improve instrument The accuracy measured and repeatability, can also make water quality on-line monitoring instrument adapt to the water sample monitoring of various colourities and turbidity simultaneously.

Accompanying drawing explanation

Fig. 1 is the change of photoelectric signal figure during sample introduction of the present invention.

Fig. 2 is level control schematic diagram of the present invention.

Fig. 3 is the schematic diagram one of the inventive method.

Fig. 4 is the schematic diagram two of the inventive method.

Detailed description of the invention

Such as Fig. 1, the present invention builds in water quality on-line monitoring instrument and automatically controls and data processing module, monitoring water quality on line During instrument sample introduction, when sample introduction liquid level by less than photoelectric metering position to higher than photoelectric metering position, opto-electronic receiver signal can occur significantly Change, when liquid level exceedes more than photoelectric metering position, opto-electronic receiver signal no longer changes.When sample introduction liquid level is by exceeding photoelectric metering Position and when returning to photoelectric metering position, opto-electronic receiver signal changes equally.

Such as Fig. 2, build in water quality on-line monitoring instrument and automatically control and data processing module, water quality on-line monitoring instrument sample introduction Time, by peristaltic pump pumps sample or reagent to gauge line, when sample introduction liquid level is less than photoelectric metering position, photosignal maintains At H0, when liquid level is close to photoelectric metering position, photosignal starts drastically to change.And when liquid level is higher than photoelectric metering position one After set a distance, photosignal intensity maintains H1.Liquid level from less than photoelectric metering position to higher than photoelectric metering position, photosignal becomes Change amplitude is (H1-H0).After sample introduction liquid level is higher than photoelectric metering position certain distance, automatic control module controls peristaltic pump at a slow speed Reversion, liquid level starts to retreat to photoelectric metering position, when identifying that software detection starts to change to photosignal, automatic control module Slack-off peristaltic pump rotating speed, sample introduction liquid level slowly approaches to photoelectric metering position, when data processing module judges that liquid level is close to photoelectrometer During amount position, it is slack-off that automatic control module controls peristaltic pump rotating speed again.When automatic identification procedure detects that photosignal changes from H1 During for the certain proportion of (H1-H0), as photosignal has changed A*(H1-H0 from H1) time (A < 1), i.e. judge that sample introduction liquid level arrives Accurately photoelectric metering position, peristaltic pump stops operating, and sample introduction accurate measurement completes.

This method principle is: control program, when controlling feed liquor, makes liquid level arrive and further exceeds metering position.Method is Detection liquid level starts change close to photosignal during metering position (liquid level one position), (arrives liquid when liquid level rises to certain altitude Position, face two) after, detect when photosignal no longer changes, control program validation liquid level and exceeded metering position.So, journey is controlled Sequence intactly detect liquid level close to metering position and higher than metering position whole during the change of photoelectric signal situation, such as Fig. 3. So, in the change of photoelectric signal figure, the corresponding liquid level determined of each ratio point of the change of photoelectric signal.I.e. figure below In, liquid level A is only the most relevant with the change ratio of photosignal, unrelated with the absolute value of the change of photoelectric signal, the most just turbid with liquid Degree and colourity are unrelated.

Specific implementation method is: after liquid level exceedes metering position, controls programme-control liquid level and returns, sets when liquid level returns to Fixed ratio A(program is fixed, such as value 0.6), then liquid level i.e. arrives a liquid level determined (liquid level A).As long as therefore Ratio A is fixed, then metering all arrives this liquid level every time, therefore measures reproducible, and precision is high.

Claims (3)

1. a high accuracy sample injection method, it is characterised in that: photoelectric metering formula sample introduction based on water quality on-line monitoring instrument is the most logical Cross water quality on-line monitoring instrument control sample introduction liquid level and exceed photoelectric metering position, then it is slow to control sample introduction liquid level by water quality on-line monitoring instrument Speed returns photoelectric metering position, and photosignal waveform when exceeding photoelectric metering position according to sample introduction liquid and return photoelectric metering position becomes Changing feature, preset ratio A, there is corresponding relation in this ratio A and liquid level, thus can accurately detect and control liquid level arrival and be somebody's turn to do Fixing position, reaches accurate measurement and improves the purpose of measurement reproducibility.

A kind of high accuracy sample injection method the most according to claim 1, it is characterised in that: exceed photoelectrometer according to sample introduction liquid Photosignal data variation feature when measuring position and return photoelectric metering position, sets out ratio value A, the most in advance according to ratio value A further determines that and measures liquid level position accurately, and process is as follows:

During sample introduction, when sample introduction liquid level rises towards from H0 and reaches near photoelectric metering position, due to liquid turbidity, colourity and Refractive index affects, and the photosignal data received significantly change；Height H1, light is arrived when sample introduction liquid level exceedes photoelectric metering position Electrical signal data no longer changes；When sample introduction liquid level returns at a slow speed photoelectric metering position, photosignal data change again；Root Photosignal waveform variation characteristic when exceeding photoelectric metering position according to sample introduction liquid and return photoelectric metering position, calculates ratio value A；When sample introduction liquid level returns A*(H1-H0) time, i.e. sample introduction liquid level arrives accurate photoelectric metering position.

A kind of high accuracy sample injection method the most according to claim 1, it is characterised in that: structure in described water quality on-line monitoring instrument Have and control feed liquor and move back the automatic control module of liquid speed, and data processing module.