A kind of measurement flow cell
Technical field
This utility model relates to a kind of measurement apparatus, particularly relates to a kind of flow cell measuring the absorbance of low concentration material in water sample and concentration.
Background technology
Environmental problem has become whole world focus of attention problem, either developed country or developing country, suffers from the negative effect that environmental pollution brings, and in the control of environmental pollution, the detection protection of water environment is particularly important with pollution control.In order to realize being controlled the content of pollutant index every in water quality, international and national has formulated different standards respectively according to different water quality, and domestic and international substantial amounts of relevant enterprise develops multiple-quality water on-line monitoring instrument the most in succession.
Measure the core component that detection cell is water quality on-line monitoring instrument table.Usually, the low concentration material in solution, during measurement, absorbance is less than normal, and the subtle disruption of absorbance all can be caused the relatively large deviation of measured matter concentration, the accuracy of impact detection data by extraneous factor.At present, the measurement apparatus of online water analysis instrument, the colorimetric light path generally used is less, and sensitivity is on the low side, it is impossible to accurately measure low concentration water sample.Meanwhile, chemical reaction during measurement is influenced by ambient temperature, and detection module is carried out high-accuracy and constant temperature control, significant for improving measurement accuracy and stability.
Utility model content
Main purpose of the present utility model, is to provide a kind of optical length, water sample to be measured quickly to mix with reagent, measurement flow cell that temperature stabilization, measurement cycle are short, for measuring absorbance and the concentration of low concentration material in water sample to be measured.
This utility model provides a kind of measurement flow cell, for measuring the concentration of measured matter in water sample, it includes color comparison tube and the one-way circulation conduit communicated, one-way circulation conduit is equiped with peristaltic pump and the first three-way valve, described first three-way valve connects with air hose, feed tube and drain pipe are accessed in the bottom of described color comparison tube, after feed liquor, water sample to be measured enters one-way circulation conduit from the lower end of color comparison tube, enter color comparison tube through one-way circulation conduit flow from upper end, by circulating up and down to import, solution to be measured in color comparison tube and reagent are quickly mixed, determine the absorbance of solution to be measured and the concentration of target component.
Preferably, described feed tube and drain pipe are by communicating alternately between the second three-way valve and color comparison tube, it is achieved the feed liquor of water sample to be measured and waste liquid are derived.
Preferably, described peristaltic pump is installed in the middle part of one-way circulation conduit, is realized importing or the derivation of water sample to be measured by forward or reverse.
Preferably, described one-way circulation conduit is U-shaped, and its two ends are connected across bottom and the top of color comparison tube, and water sample to be measured can import from the bottom of color comparison tube, and via peristaltic pump, water sample to be measured is introduced from one-way circulation conduit the top of color comparison tube, it is achieved water sample to be measured mix homogeneously in color comparison tube.
Preferably, the bottom of described color comparison tube and top are provided with light inlet window, and detection light beam is injected in colorimetric pool through light inlet window.The complex that the target monitoring factor in water sample to be measured and reagent reacting are formed, to incident illumination selective absorbing, detects signal by detector unit, can calculate absorbance and corresponding material concentration according to langbobier law.Described light inlet window is arranged at the opposite end of color comparison tube top and bottom so that detection light beam tiltable is injected in color comparison tube, can strengthen measurement light path, it is achieved accurately measure low concentration water sample.
Preferably, described color comparison tube is built-in with temperature sensor, for measuring the temperature of the water sample to be measured in color comparison tube.
Preferably, the outer wall of described color comparison tube is wound around resistance wire, is used for contrasting colour tube and carries out heated constant temperature, it is ensured that the temperature environment stable and consistent of chromogenic reaction when every time measuring.
Preferably, described one-way circulation conduit outer wrap has insulation film, reduces water sample to be measured and the exchange of extraneous heat.
Preferably, the liquid inlet of described one-way circulation conduit is higher than the light inlet window bottom color comparison tube, and liquid outlet is less than the light inlet window at color comparison tube top.
Preferably, one end of described first three-way valve connects with peristaltic pump, and one end connects with color comparison tube, one end and air line.
Compared with prior art, the application measures flow cell and by one-way circulation conduit, water sample to be measured and reagent shunting is imported in color comparison tube and quickly mixed so that water sample to be measured and reagent are sufficiently mixed reaction, improve the precision of Concentration Testing;Outer wall at color comparison tube is wound around resistance wire and heats water sample to be measured, and at the outer wrap insulation film of one-way circulation conduit, reduces water sample and the exchange of extraneous heat so that it is constant temperature, it is ensured that the temperature environment stable and consistent of chromogenic reaction when every time measuring.Switch feed liquor by three-way valve and go out liquid, simplifying pipeline structure, and by another three-way valve importing air, water sample to be measured is discharged from color comparison tube, the ingenious flow direction utilizing three-way valve control water sample, simplify the structure of overall flow cell.
Accompanying drawing explanation
Fig. 1 is a kind of structural representation measuring flow cell of the present utility model.
Detailed description of the invention
Below in conjunction with accompanying drawing, detailed description of the invention of the present utility model is further detailed.
This utility model provides a kind of measurement flow cell, for measuring the concentration of measured matter in water sample, it includes color comparison tube 1 and the one-way circulation conduit 2 communicated, one-way circulation conduit 2 is equiped with peristaltic pump 3 and the first three-way valve 4, described first three-way valve 4 connects with air hose 5, feed tube 6 and drain pipe 7 are accessed in the bottom of described color comparison tube 1, after feed liquor, water sample to be measured and reagent enter one-way circulation conduit 2 from the lower end of color comparison tube 1, circulating through one-way circulation conduit 2 enters color comparison tube 1 from upper end, by circulating up and down to import, the solution to be measured in color comparison tube 1 is quickly mixed, determine the absorbance of solution to be measured and the concentration of target component.
Wherein, color comparison tube 1 is for accommodating testing liquid to carry out the detection of chemical parameters, it is column, top is provided with breather, for being passed through air, the inner and outer air pressure making color comparison tube is identical, feed tube 6 and drain pipe 7 are accessed in the bottom of color comparison tube 1, feed tube 6 is connected with public pipeline by the second three-way valve 8 with drain pipe 7, it is connected between color comparison tube 1 and the second three-way valve 8 by public pipeline, one end of i.e. second three-way valve 8 is connected with color comparison tube 1 by public pipeline, and one end connects with feed tube 6, and one end connects with drain pipe 7.By controlling being turned on and off of the second three-way valve 8, if closing the second three-way valve 8, then feed tube 6 turns on public pipeline, water sample to be measured can be imported to color comparison tube 1 suction, if opening the second three-way valve 8, then drain pipe 7 turns on public pipeline, can discharge measuring complete water sample from color comparison tube 1.Described feed tube 6 and drain pipe 7 are communicated between color comparison tube 1 alternately by the second three-way valve 8, it is achieved the feed liquor of water sample to be measured and waste liquid are derived.
Described one-way circulation conduit 2 is U-shaped, its two ends are connected across bottom and the top of color comparison tube 1, water sample to be measured can import from the bottom of color comparison tube 1, and via peristaltic pump 3, water sample to be measured is introduced from one-way circulation conduit 2 top of color comparison tube 1, water sample to be measured and reagent is upper and lower mix homogeneously in color comparison tube 1, is extracted from the bottom to top by water sample to be measured by one-way circulation conduit 2, and from top to bottom circulate, direction circulation counterclockwise imports so that water sample to be measured and colour reagent quickly mix, and shorten the measurement time.
Be provided with peristaltic pump 3 at the middle part of one-way circulation conduit 2, described peristaltic pump 3 circulates the actuating unit of solution to be measured as extraction, by the rotation of peristaltic pump 3 different directions, can drive the flowing of solution different directions to be measured with forward or reverse.When rotating forward such as peristaltic pump 3, the solution to be measured that can will be imported to by metering module in color comparison tube 1, is flowed from the bottom up of one-way circulation conduit 2 and flows into color comparison tube 1 from the top of color comparison tube 1, mix homogeneously with the reagent of importing is quick bottom color comparison tube 1.Being additionally provided with the first three-way valve 4 on described one-way circulation conduit 2, described first three-way valve 4 connects with air hose 5.When closing the first three-way valve 4, then air hose 5 is conducted with one-way circulation conduit 2, imports one-way circulation conduit 2 by air from air hose 5, enters from the upper end of one-way circulation conduit 2 color comparison tube 1, waste liquid in color comparison tube 1 is by air pressure, and discharges from drain pipe 7.When opening the first three-way valve 4, then closing the connection between air hose 5, water sample to be measured can circulate in one-way circulation conduit 2.
Due to the material selective absorbing to light, therefore material contained in solution can be differentiated, such as Cu, Ni, As, Cr etc. in water sample according to specific absorption spectrum.By changing light source and reagent, this flow cell can measure multiple Monitoring factors.Carrying out absorbance and Concentration Testing to contrast the solution to be measured in colour tube, bottom and the top of described color comparison tube 1 are provided with light inlet window 9, and the detection light beam of specific wavelength is injected in colorimetric pool 1 through light inlet window 9, and receiver module receives signal, obtain measuring voltage U1.When using zero standard to clean color comparison tube, repeat above-mentioned measurement process, obtain reference voltage U2, the ratio of reference voltage U2 and measurement voltage U1 is taken the logarithm, thus obtains the absorbance of water sample to be measured.The complex that the target monitoring factor in water sample to be measured and reagent reacting are formed, to incident illumination selective absorbing, detects signal by detector unit, can calculate absorbance and corresponding material concentration according to langbobier law.Its ultimate principle is langbobier law: A=log I0/ I=kbc, when a branch of collimated monochromatic ligth is perpendicular through certain solution, the absorbance A of solution is directly proportional to the concentration c of extinction material and liquid layer thickness b.Wherein, absorbance A refers to that light passes through the incident intensity before solution or a certain material and this light denary logarithm (i.e. lg (I by the transmitted intensity ratio after solution or material0/ I)), wherein I0For incident intensity, I is transmitted light intensity.In this utility model, before testing, using titer one and titer two to test according to the testing process of water sample, to obtain correction coefficient, this correction coefficient can be used for the calculating of follow-up water sample test, to obtain the content of target elements in water sample to be measured.
Low temperature can affect the stability of chemical reaction velocity and colored complex, accordingly, it would be desirable to detection that water sample to be measured is heated.The outer wall of described color comparison tube 1 is wound around resistance wire, is used for contrasting colour tube and carries out heated constant temperature.The outer wrap of described one-way circulation conduit 2 has insulation film, reduces water sample to be measured and the exchange of extraneous heat, to ensure the temperature environment normal table of chromogenic reaction.Described color comparison tube 1 is also built-in with temperature sensor, for measuring the temperature of the water sample to be measured in color comparison tube.
During measurement, the solution to be measured imported by metering module enters color comparison tube 1 from the bottom of color comparison tube 1, when the liquid level of water sample to be measured is higher than the water inlet of one-way circulation conduit, liquid also counterclockwise flow from one-way circulation conduit 2, flow into from the top of color comparison tube, make water sample to be measured and the quick mix homogeneously of reagent, and homogeneous by outside guarantee temperature of liquid of heating.The liquid inlet of described one-way circulation conduit 2 is higher than the light inlet window 9 bottom color comparison tube 1, and liquid outlet is less than the light inlet window 9 at color comparison tube top.Described light inlet window 9 is arranged at the opposite end of color comparison tube top and bottom, as a light inlet window 9 is mountable to the left side at color comparison tube top, another light inlet window 9 can be mounted opposite the right side bottom color comparison tube, make to detect light beam to tilt to inject in color comparison tube 1, measurement light path can be strengthened, it is achieved low concentration water sample is accurately measured.
This utility model has been described in detail by above detailed description of the invention, but these are not constituted restriction of the present utility model.Protection domain of the present utility model is not limited with above-mentioned embodiment, as long as those of ordinary skill in the art modify or change according to the equivalence that this utility model disclosure is made, all should include in the protection domain described in claims.