CN2611896Y - High pureness water conductometer - Google Patents
High pureness water conductometer Download PDFInfo
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- CN2611896Y CN2611896Y CN 03220854 CN03220854U CN2611896Y CN 2611896 Y CN2611896 Y CN 2611896Y CN 03220854 CN03220854 CN 03220854 CN 03220854 U CN03220854 U CN 03220854U CN 2611896 Y CN2611896 Y CN 2611896Y
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Abstract
The utility model relates to a high pureness water conductometer belonging to the technical field of a water quality measurement apparatus and comprising an analog-circuit part, a digit-circuit part and a display part, wherein an excitation power supply of the analog-circuit part is mainly composed of a reference power supply chip, a potentiometer and an amplifier. The voltage output end of the reference power supply chip is connected with a divider circuit composed of the potentiometer and an electric resistance; the output end of the divider circuit forms a positive and negative supply output end by a forward-direction amplifier and an inversed-direction amplifier; the output end is connected with the input end of a conductometric measurement and range switching circuit through a shot-follow amplifier; the output terminals of a temperature-measurement electrical bridge and the conductometric measurement and range switching circuit are connected with the CPU input end of a digit-circuit part through an A/ D change-over circuit. The utility model has the advantages of powerful interference immunity and small error of measurement, and thus, the utility model improves measurement precision.
Description
Technical field
The utility model relates to a kind of conductivity meter, and especially a kind of high purity water conductivity meter belongs to the water quality measurement Instrument technology field.
Background technology
Water is raw material, is again medium, and the title of industrial lifeblood is arranged.Along with the continuous development of national economy, all conglomeraties such as electronics, electric power, chemical industry, medicine have proposed more and more higher requirement to water quality.The research of therefore measuring the water quality instrument becomes important topic.Understand according to the applicant, the conductivity meter that existing measurement pure water electricity is led is by the intelligence instrument of single-chip microcomputer as processor, appliance circuit is made up of numerical portion and simulation part two parts, and wherein simulation part mainly is made up of functional circuits such as power supply, temperature survey electric bridge, conductance measurement and range conversion, measuring-signal switching, electric current outputs.For example the applying date is that 94 on April 15,, application number are 94208460, to be called " intelligent conductivity meter " promptly be like this to name.
The problem that existing conductivity meter in use reflects is that stability and anti-interference ability are relatively poor, and especially measuring accuracy is difficult to satisfy the measurement request for utilization of high purity water.
Summary of the invention
The purpose of this utility model is: at the problem that prior art exists, propose a kind of high purity water conductivity meter of measuring accurate, stable height, strong interference immunity.
In order to reach above purpose, high purity water conductivity meter of the present utility model is made up of artificial circuit part, digital circuit part and display part, and wherein artificial circuit part is mainly exported each functional circuit and formed by excitation power supply, temperature survey electric bridge, conductance measurement and range conversion, electric current.Digital circuit partly comprises A/D change-over circuit, CPU and storer.It is characterized in that: described excitation power supply mainly is made up of reference power supply chip, potentiometer, amplifier, the voltage output end of described reference power supply chip connects the bleeder circuit of potentiometer and resistance composition, the output of bleeder circuit constitutes positive and negative power output end by a forward amplifier and a sign-changing amplifier.Described positive and negative power output end is penetrated the input end that connects conductance measurement and range change-over circuit with amplifier by one, and the output terminal of described temperature survey electric bridge and conductance measurement and range change-over circuit connects digital circuit partial C PU input end through the A/D change-over circuit.
Because the power supply of excitation power supply circuit output is penetrated with behind the amplifier through one, what offer conductivity sensor in conductance measurement and the range change-over circuit is positive and negative equivalent charge pulse sequence, different with the sine voltage institute of conductivity meter employing in the past, its strong interference immunity, amplitude 0-5V is adjustable, frequency 0-100MHz is adjustable, and the measuring error that is produced is little, has therefore improved measuring accuracy.
Description of drawings
Below in conjunction with accompanying drawing the utility model is further described.
Fig. 1 is embodiment power supply of the utility model, current output circuit schematic diagram.
Fig. 2 is the circuit theory diagrams of an embodiment artificial circuit part of the utility model
Fig. 3 is the circuit theory diagrams of an embodiment digital circuit part of the utility model.
Embodiment
Embodiment one
The instrument of present embodiment is a kind of conductivity meter that high-purity water power is led of measuring, and this conductivity meter is by the intelligence instrument of single-chip microcomputer as processor.Appliance circuit is made up of numerical portion and simulation part two parts, and concrete condition as shown in Figure 1, 2, 3.
Artificial circuit part mainly keeps functional circuits such as (2-5) to form by power circuit shown in Figure 1 and excitation power supply shown in Figure 2 (2-2), temperature survey electric bridge (2-1), conductance measurement and range conversion (2-4), measuring-signal switching (2-3), sampling.
Comprise ac-dc power conversion circuit (1-1), warning output circuit (1-2), current output circuit (1-3) among Fig. 1.Wherein ac-dc power conversion circuit (1-1) is made up of transformer T1, bridge heap B1-B4, integrated voltage stabilizing sheet A1-A4 and resistance capacitance.Transformer changes 220 volts of alternating currents into several roads low-voltage AC, is DC voltage through the rectification of bridge heap, provides instrumentation needed power supply by integrated voltage stabilizing sheet.Current output circuit (1-3) mainly is made up of optocoupler sheet, V/F conversion chip, amplifier, potentiometer, triode and resistance capacitance etc.According to the zero point and the range of the output of setting, to handle through single-chip microcomputer, the frequency signal by 8155 chips transmit after optocoupler sheet photoelectricity is isolated, is converted to voltage signal by the V/F chip.Zero point, range regulating circuit via amplifier, potentiometer, triode, resistance capacitance etc. are formed become the output of 4～20mA electric current with meter reading.
Excitation power supply circuit (2-2) among Fig. 2 is made up of reference power supply chip, potentiometer, amplifier etc.The excitation power supply circuit provides stable voltage by the reference power supply chip, and the bleeder circuit of being made up of potentiometer and resistance is regulated the size of excitation power supply amplitude, forms positive and negative power supply by a forward amplifier and a sign-changing amplifier.The output of this positive and negative power supply is by monolithic processor controlled electronic commutator---measuring-signal commutation circuit (2-3) control.Because this positive and negative power output end is penetrated the input end that connects conductance measurement and range change-over circuit (2-4) with amplifier by one, therefore the positive and negative power supply of output is penetrated with behind the amplifier through one, offers conductivity sensor.The excitation power supply here is positive and negative equivalent charge pulse sequence, and with the common sine voltage that adopts of conductivity meter was different in the past, this design has reduced measuring error, has improved measuring accuracy.
Temperature survey bridge diagram (2-1) is by measuring bridge circuit, forming with reference to bridge circuit and calibration bridge circuit.Measuring bridge circuit is made up of thermal resistance (R14) and divider resistance, form by fixed resistance respectively with reference to bridge circuit and calibration bridge circuit, measure bridge circuit, parallel with one another with reference to bridge circuit and calibration bridge circuit, its output terminal meets input end Y0, Y1, the Y of 4051 chips in the measuring-signal commutation circuit (2-3) respectively, conversion through electronic switch, measure bridge circuit and form electric bridge with the reference bridge circuit respectively, be used to measure the measuring error of temperature and base measuring temperature metering circuit with the calibration bridge circuit.What deserves to be mentioned is, new temperature correction method that this circuit is taked solved temperature that metering circuit amplifier that other instrument exists exists float with the time float the problem of the measuring error of bringing.
Conductance measurement and range change-over circuit (2-4) are made up of three different measuring resistance and three relays of resistance, and each resistance with parallel with one another again after a relay is connected, connects conductivity sensor respectively.According to measuring the size that electricity is led, by electronic switch conversion and control relay, range is measured in the divider resistance conversion that connects different resistances by singlechip CPU.
Temperature signal of measuring and conductance signal change the voltage that is fit to the A/D converter requirement into through the amplification of amplifier.The level shifting circuit of measuring-signal is made up of temperature amplifier and conductance amplifier and peripheral circuit.
The polarization effect of the solution when leading in order to reduce to measure high-purity water power, conductivity sensor adopt the power supply of equivalent electric charge arteries and veins.Therefore before conductance signal enters A/D converter, need keep through over-sampling, to obtain a stable voltage signal.Sampling hold circuit (2-5) mainly keeps chip LF398 and peripheral resistor capacitor circuit to form by sampling.The input end of this circuit---4053 chips, 12 pin connect the output of conductance measurement and range change-over circuit (2-4), the output of 5 pin of the output terminal of this circuit---LF398 chip and temperature survey bridge diagram (2-1) connects X1, the X0 pin of electronic switch chip 4051 in the measuring-signal commutation circuit (2-3), 35 pin of A/D change-over circuit chip in the output terminal 14 pin map interlinkings 3 of this chip respectively.
The digital circuit of instrument part as shown in Figure 3, mainly by A/D change-over circuit (3-5), expansion I/O mouth circuit (3-3), program expanded circuit (3-2), processor circuit (3-1), and keyboard, display circuit (3-4) are formed.
A/D change-over circuit (3-5) is made up of 7109A/D conversion chip and peripheral resistor capacitor circuit.To be converted to digital signal from the temperature/electric guided mode analog signal of 4051 electronic switch chips, 14 pin, and handle through the 8031CPU that expansion I/O mouth circuit (3-3) and program expanded circuit (3-2) connect in the processor circuit (3-1) by data line.
Expansion I/O mouth 8155 integrated chips and peripheral resistance capacitance are formed.Effect is the needs that satisfy the single-chip processor i/o mouth.Memory ram and a counter of 256 are provided simultaneously.
Processor circuit (3-1) is actual to be made up of single-chip microcomputer 8031, program storage, latch 74LS373, watchdog chip 25043 and some resistance capacitances.The single-chip microcomputer 8031 main data processing of being responsible for, program storage provides program for single-chip microcomputer.Latch provides data latching for the processor time-sharing multiplex.Watchdog chip is for guaranteeing the single-chip microcomputer operate as normal and the E that preserves some parameters being provided
2ROM.
Keyboard-display circuit (3-4) is made up of 8279 integrated chips, charactron, 3-8 code translator, triode, thin film switch and peripheral resistance.8279 chips and main processes and displays of 3-8 code translator and keyboard interrupt.Triode and resistance are mainly used in the driving charactron.It is to show electric conductivity value and temperature that charactron mainly acts on.Thin film switch is mainly used in provides look-at-me, is handled by single-chip microcomputer, revises or be set with related parameter.
Hardware circuit of this instrument and software design through theory checking, experimental check and complete machine use proof, have the advantage of measuring accurate, stable height, strong interference immunity, are suitable for the measurement that the on-the-spot high-purity water power of on-line measurement is continuously led.
Claims (3)
1. high purity water conductivity meter, by artificial circuit part, digital circuit part and display part, wherein artificial circuit part is mainly exported each functional circuit and is formed by excitation power supply, temperature survey electric bridge, conductance measurement and range conversion, electric current; Digital circuit partly comprises A/D change-over circuit, CPU and storer; It is characterized in that: described excitation power supply is mainly by the reference power supply chip, potentiometer, amplifier is formed, the voltage output end of described reference power supply chip connects the bleeder circuit of potentiometer and resistance composition, the output of bleeder circuit is by a forward amplifier and a sign-changing amplifier, just constitute, the negative supply output terminal, just described, the negative supply output terminal is penetrated the input end that connects conductance measurement and range change-over circuit with amplifier by one, and the output terminal of described temperature survey electric bridge and conductance measurement and range change-over circuit connects digital circuit partial C PU input end through the A/D change-over circuit.
2. according to the described high purity water conductivity meter of claim 1, it is characterized in that: described conductance measurement and range change-over circuit are made up of three different measuring resistance and three relays of resistance, each resistance with parallel with one another again after a relay is connected, connects conductivity sensor respectively.
3. according to the described high purity water conductivity meter of claim 2, it is characterized in that: described temperature survey bridge diagram is by measuring bridge circuit, forming with reference to bridge circuit and calibration bridge circuit, measuring bridge circuit is made up of thermal resistance and divider resistance, form by fixed resistance respectively with reference to bridge circuit and calibration bridge circuit, described measurement bridge circuit, parallel with one another with reference to bridge circuit and calibration bridge circuit, its output terminal connects electronic switch respectively, measures bridge circuit and forms electric bridge with the reference bridge circuit respectively with the calibration bridge circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03220854 CN2611896Y (en) | 2003-04-02 | 2003-04-02 | High pureness water conductometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03220854 CN2611896Y (en) | 2003-04-02 | 2003-04-02 | High pureness water conductometer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2611896Y true CN2611896Y (en) | 2004-04-14 |
Family
ID=34162123
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 03220854 Expired - Fee Related CN2611896Y (en) | 2003-04-02 | 2003-04-02 | High pureness water conductometer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2611896Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102353844A (en) * | 2011-06-24 | 2012-02-15 | 华南理工大学 | Two-way electrical conductivity detecting and monitoring device with symmetrical lead self-compensation and detecting and monitoring method using same |
| CN104897970A (en) * | 2015-06-05 | 2015-09-09 | 中国海洋大学 | Liquid conductivity measuring method and system based on complementary digital bridge |
-
2003
- 2003-04-02 CN CN 03220854 patent/CN2611896Y/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102353844A (en) * | 2011-06-24 | 2012-02-15 | 华南理工大学 | Two-way electrical conductivity detecting and monitoring device with symmetrical lead self-compensation and detecting and monitoring method using same |
| CN102353844B (en) * | 2011-06-24 | 2014-02-12 | 华南理工大学 | Detecting and monitoring method of two-way electrical conductivity detecting and monitoring device with symmetrical lead self-compensation |
| CN104897970A (en) * | 2015-06-05 | 2015-09-09 | 中国海洋大学 | Liquid conductivity measuring method and system based on complementary digital bridge |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |