CN202275074U - High accuracy portable water oxygen dissolving meter - Google Patents
High accuracy portable water oxygen dissolving meter Download PDFInfo
- Publication number
- CN202275074U CN202275074U CN2011203156386U CN201120315638U CN202275074U CN 202275074 U CN202275074 U CN 202275074U CN 2011203156386 U CN2011203156386 U CN 2011203156386U CN 201120315638 U CN201120315638 U CN 201120315638U CN 202275074 U CN202275074 U CN 202275074U
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- Prior art keywords
- water
- microcomputer controller
- sensor
- oxygen dissolving
- signal
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Abstract
The utility model discloses a high accuracy portable water oxygen dissolving meter, which comprises an oxygen dissolving sensor, a signal amplification and processing system of the oxygen dissolving sensor, an electronic touch screen, a flash memory, a power supply interface and a microcomputer controller. An electrochemical oxygen sensor is accessed into a P 1.1 in the microcomputer controller through amplification of signals and a preprocessing circuit, a temperature sensor PT100 is accessed into a P 6.0 of the microcomputer controller through signal amplification and processing, and the touch screen, the flash memory and an interface of an upper computer are connected with the microcomputer controller. The microcomputer controller achieves modification of measuring values and improves measuring accuracy through dynamic mean value arithmetic, cubic spline interpolation high-accuracy table look-up arithmetic and temperature compensation arithmetic. The high accuracy portable water oxygen dissolving meter simultaneously adopts quick dynamic measuring arithmetic, thereby having the advantages of being small in size, portable, economical, high in accuracy, quick and the like.
Description
Technical field
The utility model relates to a kind of novel high-precision portable water-soluble oxygen appearance, relates in particular to a kind of novel high-precision portable water-soluble oxygen appearance that can realize high-acruracy survey to the different measuring environment.
Background technology
Along with the worldwide production scale sharply enlarges; Population increases sharply, and enters the discarded object havoc existent environment of people of environment, and water pollutes particularly serious; A large amount of industry and sanitary sewage, agricultural drain severe contamination rivers,lakes and seas; Make the water quality of water resource go from bad to worse, shortage of water resources is serious day by day, so press for sewage is in time monitored and is effectively handled.Wherein, water-soluble oxygen content is an important indicator of water quality monitoring.
The factor that influences the water-soluble oxygen measuring accuracy is more, and climatic conditions change (temperature. the fluctuation of humidity and air pressure) can produce influence in various degree to the stability of oxygen sensor performance.Variation of temperature can exert an influence to the oxygen transmission rate of oxygen permeation membrane, thereby influences dissufion current.Water quality also can exert an influence to the galvanochemistry dissolved oxygen sensor, receives chemical substance or the influence of heavy metal in pH value fluctuation, the water, and when having gas such as sulfuretted hydrogen, sulphuric dioxide in the water, the galvanochemistry dissolved oxygen sensor will be polluted, and cause sensitivity to descend.The noise of amplifier nonlinearity pre-process circuit also can exert an influence to measuring accuracy.Portable water-soluble oxygen appearance is in the market solving miniaturization and when portable, and improving it, to detect degree of accuracy be an important problem.
The utility model content
The technical matters that the utility model will solve provides a kind of high-precision portable water-soluble oxygen appearance, to solve the degree of accuracy defect of insufficient of existing portable water-soluble oxygen appearance.
For solving the problems of the technologies described above, the high-precision portable water-soluble oxygen appearance that the utility model provides comprises that dissolved oxygen sensor and signal thereof amplify and disposal system, electronic touch screen, flash memory, power interface, and microcomputer controller.
The export function of measurement data for ease, the water-soluble oxygen appearance that the utility model provides also provides simple RS232 interface, can realize conveniently that measurement data is sent in the host computer.
Said signal amplifies and disposal system comprises discharge circuit, voltage controlled oscillator and photoelectrical coupler; The discharge circuit current signal that dissolved oxygen sensor is faint changes into the voltage small-signal; Voltage controlled oscillator is converted into the voltage that captures the frequency signal that is directly proportional with voltage.
Said microcomputer controller comprises MSP430F1611; Utilize its high processing ability and bigger program storage; Adopt dynamic mean algorithm, cubic spline interpolation high precision table look-up algorithm and temperature compensation algorithm, eliminate the influence of system noise, amplifier nonlinearity and environment temperature measuring accuracy.
Said touch-screen can utilize abundant menu, realizes the expansion of measurement function, can provide corresponding correcting mode to select according to measurement environment, reduces the influence of environment to measuring accuracy.
Said power interface adopts powered by direct current or ac-powered.
The principle of the utility model:
Low current signal input voltage freq converting circuit behind amplifying circuit of galvanochemistry dissolved oxygen sensor input, at this moment the frequency of signal and the dissolved oxygen amount in the water are proportional, are input to the P1.1 pin of single-chip microcomputer through the photoelectricity coupled circuit; Single-chip microcomputer is according to the input of P1.1 pin; Calculate frequency values by the frequency measurement software module, if directly frequency values is converted into dissolved oxygen amount, ratio error maybe be bigger mutually with actual value for oxygen dissolving value so at this moment; And fluctuation is also big, and is very unstable.For this reason, the utility model solves through following several kinds of algorithms.
Temperature compensation algorithm, along with variation of temperature, the coefficient of diffusion of oxygen in electrolyte solution increases, and the electrode chemical reaction velocity also increases, thereby causes that the electric current output of holding lambda sensor also increases.Under specific partial pressure of oxygen P; The output current I of dissolved oxygen sensor electrode and the relation of temperature T are:
revises output current value through this formula, thereby reaches the purpose of temperature compensation.
Kinetic measurement algorithm and dynamically mean algorithm fast, single-chip microcomputer utilize the signal measurement of certain time interval (be 300ms, the actual value of water-soluble oxygen is slowly to change) to the P1.1 pin here.If the sequence that sampling obtains is { x
1, x
2... x
i..., corresponding output sequence is { y
1, y
2... y
i..., dynamically mean algorithm is y
i=[(i-1)/and i] y
I-1+ (1/i) x
i, just the average that obtains of front and current measured value carry out weighted sum.But when i reached higher value, the weighting coefficient of currency had only 1/i, so just can not really reflect the present dynamic value, for this reason, adopted piecewise function correction here, and when measuring beginning, promptly formula y is adopted in i＜20 o'clock
i=[(i-1)/and i] y
I-1+ (1/i) x
i, when measuring the entering steady state (SS) (i＞=20), adopt formula y
i=(19/20) y
I-1+ (1/20) x
iThereby, can reduce the fluctuation of measured value, effectively eliminate the influence of Gaussian noise, can reflect actual dynamic value (up to the present still to the correction of frequency values, or frequency values) again.
The cubic spline interpolation high precision algorithm of tabling look-up; To be converted into actual water-soluble oxygen value through the water-soluble oxygen value transfer algorithm of frequency by above-mentioned dynamic mean algorithm, make full use of the high capacity program storage of single-chip microcomputer here, convert the water-soluble oxygen value/frequency curve that segments to tables of data; The segmentation degree has here reached higher precision; In order to realize higher measuring accuracy, utilize the cubic spline interpolation algorithm to come computation of table lookup, convert frequency values to actual water-soluble oxygen value.
The ambient compensation algorithm utilizes the user in touch-screen menus, to import the content of zwitterion in the flow velocity, water of water, compensates through inquiry corresponding compensation curve (having the tables of data in the flash memory).
The water-soluble oxygen appearance that the utility model provides has been realized low-power consumption, portable design.Algorithm through multiple raising measuring accuracy (dynamically mean algorithm, cubic spline interpolation high precision table look-up algorithm and temperature compensation algorithm) improves measuring accuracy.Through touch-screen menus input environment essential information; Utilize multiple algorithm to revise the influence of environment to measuring accuracy; Also adopted quick kinetic measurement algorithm simultaneously, the utlity model has miniaturization, portable the time, also have advantages such as economical, high precision and rapidity thereby make.
Description of drawings
Fig. 1 is the planar structure and the fundamental diagram of this practicality.
Fig. 2 is amplification, the pre-process circuit figure of the signal of the utility model.
The circuit diagram that Fig. 3 handles for the utility model temperature sensor signal.
Fig. 4 is the utility model power module circuitry figure.
Fig. 5 is 16 single-chip minimum system circuit diagrams of the utility model.
Fig. 6 is the utility model touch-screen and flash memory circuit figure.
Fig. 7 is the utility model RS232 communication interface circuit figure.
Embodiment
Below in conjunction with Figure of description the utility model is further specified.
As shown in Figure 1; The high-precision portable water-soluble oxygen appearance that the utility model provides, its hardware is made up of dissolved oxygen sensor and amplifying circuit thereof, voltage frequency conversioning circuit, photoelectricity coupled circuit, MSP430 minimum system, 5 inches touch-screens, flash memory, RS232 interface circuits.Adopt backoff algorithm, fast kinetic measurement algorithm, dynamic table look-up algorithm, ambient compensation algorithm of mean algorithm, cubic spline interpolation high precision in the software design, thereby guaranteed high-precision requirement.
As shown in Figure 2; The amplification of the signal of galvanochemistry dissolved oxygen sensor, pre-process circuit figure comprise dissolved oxygen sensor interface IN+, IN-; The dissolved oxygen sensor signal amplification circuit of forming by resistance (R1, R2, R3, R5, R6), capacitor C 1, potentiometer R4, ballast diode Z1, amplifier CA3140, power supply+12 and ground GND; The voltage frequency conversioning circuit of forming by resistance (R7, R8, R9), electric capacity (C2, C3), voltage-frequency converter AD654, power supply+12 and ground GND, by resistance (R10, R11, R12), photoelectrical coupler U3, power supply VCC3 and the photoelectricity coupled circuit formed of GND.
As shown in Figure 3, the circuit that temperature sensor signal is handled is made up of temperature sensor PT100, resistance (RT1, RT2, RT3, R22, R23, R24, R25) and amplifier LM124.
As shown in Figure 4, power module circuitry is made up of 12v lithium battery, electric capacity (C6, C7, C8, C10, C11, C12), electrochemical capacitor (C5, C9, C13), resistance R 15, light emitting diode D1, power module 7805 and power module 1117-3.3.
As shown in Figure 5; The MSP430 single-chip minimum system comprises the reset circuit of being made up of resistance (R13, R14), capacitor C 14, pushbutton switch S_RST; The low speed crystal oscillating circuit of forming by electric capacity (C12, C13) and low speed crystal oscillator Y2; High speed crystal oscillating circuit, MSP430F1611 chip and the jtag interface circuit formed by electric capacity (C15, C16) and high speed crystal oscillator Y1.
As shown in Figure 6; Touch-screen and flash memory circuit comprise the bus level two-way changing circuit of being made up of 2 74lvc4245; The bleeder circuit of the touch-screen look-at-me that constitutes by resistance R 88 and R89; The bleeder circuit of the touch-screen busy signal that constitutes by resistance R 90 and R919, flash chip 24C512 and touch screen interface circuit.
As shown in Figure 7, the RS232 communication interface circuit is made up of electric capacity (C31, C32, C33, C34), RS232 chip for driving and RS232 interface.
The utility model is set up ambient compensation curve data table, temperature compensation curve tables of data, frequency/dissolved oxygen amount curve data table in flash memory; Content through zwitterion in the flow velocity, water of input water in the touch-screen menus; Compensate through the ambient compensation algorithm, realize revising the influence of environmental factor measuring accuracy.Algorithm through multiple raising measuring accuracy (dynamically mean algorithm, cubic spline interpolation high precision table look-up algorithm and temperature compensation algorithm) further improves measuring accuracy.The utility model has significantly reduced the influence of complicated algorithm to system through adopting the tables of data of setting up in the flash memory, increases the sampling number of unit interval, thereby further improves measuring accuracy again, can also improve measuring speed simultaneously.The utility model is realized good measurement performance through abundant succinct effectively software algorithm and flash memory technology under the situation that increases hardware cost hardly.Thereby make and the utlity model has miniaturization, portable the time, also have advantages such as economical, high precision and rapidity.
Though the utility model with preferred embodiment openly as above; But it is not in order to limit the present invention; Anyly be familiar with this technological people; Do not breaking away from the spirit and scope of the present invention, all can do various changes and modification, so protection scope of the present invention should be as the criterion with what claims were defined.
Claims (5)
1. a high-precision portable water-soluble oxygen appearance comprises that dissolved oxygen sensor and signal thereof amplify and disposal system, electronic touch screen, and flash memory, power interface is characterized in that also comprising microcomputer controller.
2. water-soluble oxygen appearance according to claim 1 is characterized in that also comprising the RS232 interface, realizes that measurement data is sent in the host computer.
3. water-soluble oxygen appearance according to claim 1 and 2 is characterized in that said signal amplifies and disposal system comprises discharge circuit, voltage controlled oscillator and photoelectrical coupler; The discharge circuit current signal that dissolved oxygen sensor is faint changes into the voltage small-signal; Voltage controlled oscillator is converted into the voltage that captures the frequency signal that is directly proportional with voltage.
4. water-soluble oxygen appearance according to claim 3 is characterized in that said microcomputer controller comprises MSP430F1611.
5. water-soluble oxygen appearance according to claim 3 is characterized in that said power interface adopts powered by direct current or ac-powered.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203156386U CN202275074U (en) | 2011-08-26 | 2011-08-26 | High accuracy portable water oxygen dissolving meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203156386U CN202275074U (en) | 2011-08-26 | 2011-08-26 | High accuracy portable water oxygen dissolving meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202275074U true CN202275074U (en) | 2012-06-13 |
Family
ID=46195422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011203156386U Expired - Lifetime CN202275074U (en) | 2011-08-26 | 2011-08-26 | High accuracy portable water oxygen dissolving meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202275074U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103210875A (en) * | 2012-01-20 | 2013-07-24 | 韩山师范学院 | Low-carbon energy-saving aeration system |
| CN113030186A (en) * | 2021-03-04 | 2021-06-25 | 南宁诺博仪器仪表有限公司 | Pen type dissolved oxygen instrument |
-
2011
- 2011-08-26 CN CN2011203156386U patent/CN202275074U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103210875A (en) * | 2012-01-20 | 2013-07-24 | 韩山师范学院 | Low-carbon energy-saving aeration system |
| CN113030186A (en) * | 2021-03-04 | 2021-06-25 | 南宁诺博仪器仪表有限公司 | Pen type dissolved oxygen instrument |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee | ||
| CP03 | Change of name, title or address |
Address after: 310012 , 164 Wen two road, Hangzhou, Zhejiang, Hangzhou Institute of Commerce Patentee after: Zhejiang Shuangliang SHANGDA Environmental Protection Co Ltd Address before: 310018 , 164 Wen two road, Hangzhou, Zhejiang, Hangzhou Institute of Commerce Patentee before: Zhejiang Shangda Environmental Protection Co., Ltd. |
|
| CX01 | Expiry of patent term |
Granted publication date: 20120613 |
|
| CX01 | Expiry of patent term |