CN101216339B - Electromagnetic flux converter simulated calibration apparatus - Google Patents
Electromagnetic flux converter simulated calibration apparatus Download PDFInfo
- Publication number
- CN101216339B CN101216339B CN2008100521041A CN200810052104A CN101216339B CN 101216339 B CN101216339 B CN 101216339B CN 2008100521041 A CN2008100521041 A CN 2008100521041A CN 200810052104 A CN200810052104 A CN 200810052104A CN 101216339 B CN101216339 B CN 101216339B
- Authority
- CN
- China
- Prior art keywords
- circuit
- output
- input
- chip microcomputer
- electromagnetic flux
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/56—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using electric or magnetic effects
- G01F1/58—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using electric or magnetic effects by electromagnetic flowmeters
- G01F1/60—Circuits therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
- G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters
Abstract
The invention relates to an analogue calibration device for an electromagnetic flow converter, solving the calibration problem of the electromagnetic flow converter. The technical proposal includes that the analogue calibration device comprises a frequency receiving circuit with the input end connected with the output end of the calibrated electromagnetic flow converter to be calibrated and the output end connected with the input interfaces of a single chip microcomputer and peripheral circuits; a communication circuit with the input end connected with signal interfaces of the single chip microcomputer and peripheral circuits and the output end connected with the calibrated electromagnetic flow meter converter; a LCD interface with the input end connected with the output ends of the single chip microcomputer and peripheral circuits; the single chip microcomputer and peripheral circuits with the input ends connected with the output ends of a keystroke circuit and the frequency receiving circuit and the output ends connected with an analogue signal generating circuit, the communication circuit and the LCD interface; an exciting signal transfer circuit with the input end connected with the output end of the exciting circuit of the electromagnetic flow converter to be calibrated; and an analogue signal generating circuit with the input end connected with the output ends of the exciting signal transfer circuit, the single chip microcomputer and peripheral circuits and the output end connected with the input end of the electromagnetic flow converter to be calibrated.
Description
Technical field:
The present invention relates to measure the electromagnetic flowmeter that continuous stream is crossed the conducting liquid volumetric flow rate of instrument, specifically be the simulated calibration apparatus of electromagnetic flux converter in the electromagnetic flowmeter, can realize the simulated calibration work of electromagnetic flux converter by this device at any time, everywhere.
Technical background
Electromagnetic flowmeter is the novel flow measurement instrument that develops rapidly along with the development of electronics, mechanics of communication the sixties. it is made according to Faraday's electromagnetic induction law, is used for measuring the volumetric flow rate of conductive fluid.Since its unique advantage, the present measurement that has been widely used in industrial various conducting liquids. for example, measure corrosive liquids such as various acid, alkali, salt; Various inflammable, explosive medium; Various industrial sewages, paper pulp, the measurement of mud etc.Comprise electromagnetic flow transducer and electromagnetic flux converter in the electromagnetic flowmeter, they all must be demarcated before the use of dispatching from the factory, electromagnetic flux converter is generally fixed at the enterprising rower of actual pipeline with electromagnetic flow transducer in process of production, the promptly real method of deciding of failing to be sold at auction, but the real method of deciding of failing to be sold at auction exists: A. builds the caliberating device complexity, expensive, B. real failing to be sold at auction decided the realistic accuracy that precision can not be represented on-the-spot use, the caliberating device inconvenience of C. building at any time, with need, problem such as move everywhere, for this reason, the patent No. be CN1908599A's " based on the electromagnetic flowmeter dried calibration method of pipe segment inner surface magnetic field point-to-point measurement " and the patent No. be CN1908598A " based on the electromagnetic flowmeter dried calibration method of flat magnetic field point-to-point measurement " patent disclosure to the dried calibration method of sensor in the electromagnetic flowmeter, but the demarcation document to the electromagnetic flux converter in the electromagnetic flowmeter is not seen as yet, in addition, necessary supporting use between electromagnetic flux converter and the electromagnetic flow transducer, along with electromagnetic flowmeter use increasingly extensive, how to improve the matching used interchangeability of electromagnetic flux converter and electromagnetic flow transducer, application and production run also have great importance at the scene.
Summary of the invention
The present invention provides and discloses a kind of simulated calibration apparatus of electromagnetic flux converter for solving the problems referred to above that prior art exists.Its cost is lower, can realize the staking-out work of electromagnetic flux converter at any time, everywhere, as required in process of production, realizes the consistance of electromagnetic flux converter, improves and works into productive rate, reduces the production link cost.
For reaching above purpose, the technical solution used in the present invention includes: input is connected in the frequency output circuit of electromagnetic flux converter to be calibrated, and output is connected in the frequency receiving circuit of single-chip microcomputer and peripheral circuit flow signal input interface; Input is connected in single-chip microcomputer and peripheral circuit output interface, and output is connected in the communicating circuit of electromagnetic flux converter to be calibrated; Input is connected in the LCD interface of single-chip microcomputer and peripheral circuit output; Input interface is connected in the output interface of key circuit, frequency receiving circuit, and output is connected in the single-chip microcomputer and the peripheral circuit of simulating signal generative circuit, communicating circuit, LCD interface; Output is connected in the key circuit of single-chip microcomputer and peripheral circuit, also includes input and is connected in electromagnetic flux converter field circuit output to be calibrated, receives the excitation signal translation circuit of excitation signal; Input is connected in the excitation signal translation circuit, single-chip microcomputer and peripheral circuit output, and output is connected in the simulating signal generative circuit of signal sample circuit input in the electromagnetic flux converter to be calibrated.
Its excitation signal translation circuit is connected in electromagnetic flux converter field circuit output to be calibrated by input, receives two photoelectric coupled circuit of excitation signal; Arm field effect transistor grid is controlled by above-mentioned optocoupler output, and output is connected in the bridge circuit of simulating signal generative circuit input; Being connected in the bridge circuit input end constitutes to the constant-current source circuit of its power supply.
High precision, the low temperature that its simulating signal generative circuit is connected in excitation signal translation circuit output by the input resistance in series bleeder circuit that wafts; Triode, relay switch output voltage controlling circuit that input is connected in each control pin output of single-chip microcomputer constitute.
Its principle of work is: electromagnetic flux converter is according to Faraday's electromagnetic induction law, and the conducting liquid induced voltage that measure to flow is determined flow signal.An aanalogvoltage generation system is formed by precision element in simulated calibration apparatus inside, can simulate the voltage signal of the flow velocity signal of corresponding 0.1-10m./s.In the test process, electromagnetic flux converter sends excitation signal by field circuit, simulated calibration apparatus sends the corresponding analog voltage signal of waveform with it after collecting excitation signal, electromagnetic flux converter collects behind the analog voltage signal through being converted into flow signal, promptly export the correspondent frequency signal, this frequency signal simulated caliberating device collection and supervision.In the test process, the frequency signal that simulated calibration apparatus automatic switching signal intensity and acquisition stream energy converter return.After test process was finished, whether the linearity that simulated calibration apparatus can analyze electromagnetic flux converter satisfied performance requirement, carried out data scaling by communication interface to satisfying the linear electromagnetic flux converter that requires through the data-optimized back of handling.
Advantage and good effect: the simulated calibration apparatus A. of electromagnetic flux converter of the present invention is because used optically-coupled, constant current, bridge circuit in the excitation signal translation circuit, so make to input to that simulating signal generative circuit signal is more stable, amplitude is more consistent, make demarcation more accurate.B. because the simulating signal generative circuit has used high precision, low temperature to float the resistance in series bleeder circuit and input is connected in triode, the relay switch output voltage controlling circuit that the Single-chip Controlling pin is exported, make analog output voltage accurate, stable, thereby make demarcation more accurate, demarcating the output voltage loop can be changed by Single-chip Controlling.C. the simulated calibration apparatus cost of this electromagnetic flux converter low and can be at any time, with need, to move forward into rower everywhere fixed.D. electromagnetic flux converter demarcate accurately and with electromagnetic flow transducer between supporting, consistent.
Description of drawings
Fig. 1: be the simulated calibration apparatus circuit structure block diagram of a kind of electromagnetic flux converter of the present invention;
Fig. 2: be the simulated calibration apparatus circuit theory diagrams of a kind of electromagnetic flux converter of the present invention.
Fig. 3: for the simulated calibration apparatus of a kind of electromagnetic flux converter of the present invention is demarcated process flow diagram.
Embodiment
In order to further specify content of the present invention, technical scheme and characteristics, lift following example again and be described with reference to the accompanying drawings as follows:
Fig. 1 is a simulated calibration apparatus circuit structure block diagram, as shown in Figure 1, the technical scheme that the simulated calibration apparatus of electromagnetic flux converter of the present invention adopts includes: input is connected in the frequency output circuit of electromagnetic flux converter to be calibrated, and output is connected in the frequency receiving circuit 3 of single-chip microcomputer and peripheral circuit input interface; Input is connected in single-chip microcomputer and peripheral circuit output interface, and output is connected in the communicating circuit 4 of electromagnetic flux converter to be calibrated; Input is connected in the LCD interface 5 of single-chip microcomputer and peripheral circuit output; Input interface is connected in key circuit 7, frequency receiving circuit 3, and output is connected in the single-chip microcomputer and the peripheral circuit 6 of simulating signal generative circuit 2, communicating circuit 4, LCD interface 5; Output is connected in the key circuit 7 of single-chip microcomputer and peripheral circuit, also includes: input is connected in electromagnetic flux converter field circuit output to be calibrated, receives the excitation signal translation circuit 1 of excitation signal; Input is connected in the excitation signal translation circuit, single-chip microcomputer and peripheral circuit output, and output is connected in the simulating signal generative circuit 2 of signal sample circuit input in the electromagnetic flux converter to be calibrated.
Its excitation signal translation circuit is connected in electromagnetic flux converter field circuit output to be calibrated by input, receives two photoelectric coupled circuit of excitation signal; Arm field effect transistor grid is connected in optocoupler output, and output is connected in the bridge circuit of simulating signal generative circuit input; Being connected in the bridge circuit input end constitutes to the constant-current source circuit of its power supply.
Its simulating signal generative circuit floats the resistance in series bleeder circuit by high precision, the low temperature that input is connected in the output of excitation signal translation circuit; Triode, relay switch output voltage controlling circuit that input is connected in the output of Single-chip Controlling pin constitute.
Its calibration principle is: electromagnetic flux converter to be calibrated sends excitation signal to simulated calibration apparatus B automatically by field circuit, simulated calibration apparatus sends the corresponding analog voltage signal of waveform with it after collecting excitation signal, and the amplitude of its analog voltage signal can be adjusted automatically.Electromagnetic flux converter collects behind the analog voltage signal through being converted into flow signal, the frequency signal that output is corresponding, this frequency signal simulated caliberating device B collection and monitors, and calculates the flow signal size that can obtain electromagnetic flux converter by single-chip microcomputer.Simulated calibration apparatus automatic switching signal intensity is also gathered the frequency signal that electromagnetic flux converter returns.After test process was finished, whether the linearity that simulated calibration apparatus can analyze electromagnetic flux converter satisfied the specification error requirement, carried out data scaling by communication interface to satisfying the linear electromagnetic flux converter that requires through the data-optimized back of handling.Simulated calibration apparatus can carry out the adjustment of corrected parameter data by button, and liquid crystal can show test process information.
Fig. 2 is the simulated calibration apparatus circuit theory diagrams of electromagnetic flux converter of the present invention.As shown in the figure, the simulated calibration apparatus of electromagnetic flux converter of the present invention mainly is made up of 7 parts that frame of broken lines is represented, comprising: input is connected in electromagnetic flux converter field circuit output to be calibrated, receives the excitation signal translation circuit 1 of excitation signal; Input is connected in excitation signal translation circuit and single-chip microcomputer and peripheral circuit output, and output is connected in the simulating signal generative circuit 2 of signal sample circuit input in the electromagnetic flux converter to be calibrated; Input is connected in the frequency output circuit of electromagnetic flux converter to be calibrated, and output is connected in the frequency receiving circuit 3 of single-chip microcomputer and peripheral circuit interface; Input is connected in single-chip microcomputer and peripheral circuit output interface, and output is connected in the communicating circuit 4 of electromagnetic flux converter to be calibrated; Input is connected in the LCD interface 5 of single-chip microcomputer and peripheral circuit output interface; Input interface is connected in key circuit, frequency receiving circuit, and output is connected in the single-chip microcomputer and the peripheral circuit 6 of simulating signal generative circuit, communicating circuit, LCD interface; Output is connected in the key circuit 7 of single-chip microcomputer and peripheral circuit.
Electrical schematic diagram of the present invention is as shown in Figure 2: among the figure, excitation signal translation circuit 1, its input interface J2 connects the field circuit output of electromagnetic flux converter to be calibrated, and the excitation signal alternating signal makes optocoupler U1 and U2 by resistance R 14, R17, R15, R16 alternate conduction through R20, R38, R39.During the U1 conducting, brachium pontis Q1, Q4 field effect transistor are opened by R18 and are formed the loop; During the U2 conducting, brachium pontis Q2, Q3 field effect transistor are opened by R18 and are formed the loop.Operational amplification circuit U4A, resistance R 11, R12, R13, R19 and triode Q5 constitute constant-current circuit, the control loop current constant, loop current flows through R18 and produces voltage, polarity of voltage but constant amplitude corresponding with the excitation signal direction, voltage signal reaches the R22-R37 series circuit of simulating signal generative circuit 2 after the conversion.
Simulating signal generative circuit 2 adopts the electric resistance partial pressure principle, selects the resistance R 22-R37 series circuit high-accuracy, that low temperature floats for use, improves the dividing potential drop precision.Behind the excitation signal translation circuit 1 conversion excitation signal, export, and import in resistance in series R24, R25 by R18.
In addition, the control of the single-chip microcomputer U7 in single-chip microcomputer and the peripheral circuit 6 pin 21 to 26 is connected to triode Q6-Q11, the relay switch K5-K10 of simulating signal generative circuit and the output voltage controlling circuit that resistance in series is formed by R4-R10 respectively.For example, when Single-chip Controlling pin two 6 is high level, triode Q6 conducting, relay K 4 adhesives, other relay control mode unanimity.The corresponding output loop conducting of may command after the actuating of relay, the magnitude of voltage that different circuit is corresponding different.Different magnitudes of voltage connects the signal sample circuit input end of electromagnetic flux converter to be calibrated by the output interface J6 of simulating signal generative circuit.The effect of simulating signal generative circuit 2 is by the different voltage output loop of relay control, at the different aanalogvoltage of interface J6 terminal output, interface J6 is connected to the signal sample circuit input of being demarcated electromagnetic flux converter, the induced voltage that the analog electrical Magnetic Sensor produces.
The input interface J3 of frequency receiving circuit 3 is connected in the frequency output circuit of electromagnetic flux converter to be calibrated, receives its delivery rate frequency signal, shows as Fig. 2, and it is made up of input resistance R21, optocoupler U3, output resistance R3.Principle of work is: the frequency signal of electromagnetic flux converter output to be calibrated is connected to the pin one 2 of the single-chip microcomputer U7 in single-chip microcomputer and the peripheral circuit 6 by interface J3 input by output behind the optocoupler.Single-chip microcomputer can obtain the frequency signal and the storage of electromagnetic flux converter output by the conversion that detects the pin level.The frequency signal of electromagnetic flux converter output is not the level signal that single-chip microcomputer can directly detect, and therefore the frequency signal of electromagnetic flux converter being exported by the frequency receiving circuit converts the level signal that single-chip microcomputer can directly detect to.
Communicating circuit 4 adopts and isolates communication mode, is produced by insulating power supply module J 1 and isolates power supply.U2 is serial communication chip MAX232, form communication interface with capacitor C 3, C4, C5, C6, C8, resistance R 2, R5, the R1 that its input end optocoupler U5, U7 connect power supply by an end connects 10,11 pin of single-chip microcomputer and peripheral circuit, and its output is connected to electromagnetic flux converter communicating circuit to be calibrated by 1,2,3 of interface J4.LCD interface 5, by interface J5 3,4-11 is connected to single-chip microcomputer and peripheral circuit output pin 16,32-39.
Single-chip microcomputer and peripheral circuit 6, its 9 pin connects C7, R15 and forms electrify restoration circuit, and 18,19 pin connect C1, C2, CY2 forms passive crystal oscillating circuit, single-chip microcomputer U7 selects P89V51RD2 for use, belong to the 80C51 series of products, built-in 64K program storage, DIP40 encapsulation.
U7 pin one 0,11 and communicating circuit 4 link to each other by optocoupler, carry out data communication.U7 pin one 6,32 to 39 links to each other with LCD interface J5, carries out LCD Controller, shows procedural information and result in the calibration process.
Key circuit 7, wherein R40, R41, R42, R43 are pull-up resistor, and button K1, K2, K3, K4 are serially connected with between power supply VCC and the ground, button K1, K2, K3, K4 output are connected to the pin one to 4 of single-chip microcomputer U7 in single-chip microcomputer and the peripheral circuit 6, can control some parameter informations of calibration process and input calibration device by button.
Fig. 3 is that simulated calibration apparatus of the present invention is demarcated FB(flow block), and as shown in Figure 3: it is demarcated flow process and is divided into: system initialisation phase; Whether press " demarcation " button and judge the stage; In this way, Single-chip Controlling simulating signal generative circuit " sends the analog voltage signal of different sizes " to the electromagnetic flux converter stage to be measured; Electromagnetic flux converter to be measured calculates the flow signal size and sends frequency signal after detecting analog voltage signal, and single-chip microcomputer is by frequency receiving circuit " frequency acquisition signal " and memory phase in the simulated calibration apparatus; " whether test point tests is finished the judgement stage "; In this way, be ordinate with the analog voltage signal, receiving frequency signals is a horizontal ordinate, " calculating each point slope and slope mean value stage "; " whether each point slope and average maximum deviation judge the stage less than permissible error "; In this way, think that then the linearity meets the demands, " showing linear normal phase "; " the slope average is sent to the electromagnetic flux converter to be measured stage by communicating circuit " and demarcates and finish,, then " point out linear failure phase " as not.
Claims (1)
1. the simulated calibration apparatus of an electromagnetic flux converter includes: import and be connected in electromagnetic flux converter medium frequency output circuit to be calibrated, export the frequency receiving circuit that is connected in single-chip microcomputer and peripheral circuit flow signal input interface; Input is connected in single-chip microcomputer and peripheral circuit output interface, and output is connected in the communicating circuit of electromagnetic flux converter to be calibrated; Input is connected in the LCD interface of single-chip microcomputer and peripheral circuit output; Input interface is connected in the output interface of key circuit, frequency receiving circuit, and output is connected in the single-chip microcomputer and the peripheral circuit of simulating signal generative circuit, communicating circuit, LCD interface; Output is connected in the key circuit of single-chip microcomputer and peripheral circuit, it is characterized in that: also include input and be connected in electromagnetic flux converter field circuit output to be calibrated, receive the excitation signal translation circuit of excitation signal; Input is connected in the excitation signal translation circuit, single-chip microcomputer and peripheral circuit output, output is connected in the simulating signal generative circuit of signal sample circuit input in the electromagnetic flux converter to be calibrated, above-mentioned excitation signal translation circuit is connected to electromagnetic flux converter field circuit output to be calibrated by input, receives two photoelectric coupled circuit of excitation signal; Arm field effect transistor grid is connected in optocoupler output, output is connected in the bridge circuit of simulating signal generative circuit input and is connected in the bridge circuit input end, constant-current source circuit to its power supply constitutes, and above-mentioned simulating signal generative circuit floats the resistance in series bleeder circuit by high precision, the low temperature that input is connected in the output of excitation signal translation circuit; The triode relay switch output voltage controlling circuit that input is connected in each control pin output of single-chip microcomputer constitutes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100521041A CN101216339B (en) | 2008-01-18 | 2008-01-18 | Electromagnetic flux converter simulated calibration apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100521041A CN101216339B (en) | 2008-01-18 | 2008-01-18 | Electromagnetic flux converter simulated calibration apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101216339A CN101216339A (en) | 2008-07-09 |
| CN101216339B true CN101216339B (en) | 2010-08-11 |
Family
ID=39622817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2008100521041A Expired - Fee Related CN101216339B (en) | 2008-01-18 | 2008-01-18 | Electromagnetic flux converter simulated calibration apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101216339B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101980040A (en) * | 2010-10-19 | 2011-02-23 | 哈尔滨工业大学（威海） | On-line calibration device of induction type cored magnetic sensor |
| CN105890718B (en) * | 2014-12-03 | 2023-01-13 | 杭州派乐科技有限公司 | Portable multi-channel flow integrating instrument field calibrator and control circuit thereof |
| CN108354450A (en) * | 2018-04-27 | 2018-08-03 | 哈工大机器人集团（哈尔滨）资产经营管理有限公司 | Wine blending device |
| CN110398279A (en) * | 2019-08-12 | 2019-11-01 | 杭州源牌环境设备有限公司 | A kind of electromagnetic flowmeter flow rate test tooling caliberating device |
| CN111879367B (en) * | 2020-08-03 | 2022-05-17 | 江苏工程职业技术学院 | Electromagnetic flowmeter system and control circuit based on Internet of things |
| CN112097820A (en) * | 2020-09-02 | 2020-12-18 | 霍丁格必凯(苏州)电子测量技术有限公司 | Calibration box of analog signal transmitter |
| CN112229457B (en) * | 2020-11-19 | 2021-09-21 | 吉林大学 | Novel electromagnetic flowmeter and measuring method thereof |
| CN113252146A (en) * | 2021-05-13 | 2021-08-13 | 宁波水表(集团)股份有限公司 | Intelligent flow velocity simulation system |
| CN113295245B (en) * | 2021-05-21 | 2022-03-11 | 宁波水表(集团)股份有限公司 | Electromagnetic water meter converter and calibration method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5604684A (en) * | 1993-12-30 | 1997-02-18 | Juntunen; Robert D. | Embedded programmable sensor calibration method |
| CN1410742A (en) * | 2002-10-14 | 2003-04-16 | 杭州电子工业学院 | Intelligent frequency conversion, current transform type excitation method and electromagnetic flow meter |
| CN1673695A (en) * | 2005-04-21 | 2005-09-28 | 上海大学 | Tester for electromagnetic flowmeter signal converter |
-
2008
- 2008-01-18 CN CN2008100521041A patent/CN101216339B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5604684A (en) * | 1993-12-30 | 1997-02-18 | Juntunen; Robert D. | Embedded programmable sensor calibration method |
| CN1410742A (en) * | 2002-10-14 | 2003-04-16 | 杭州电子工业学院 | Intelligent frequency conversion, current transform type excitation method and electromagnetic flow meter |
| CN1673695A (en) * | 2005-04-21 | 2005-09-28 | 上海大学 | Tester for electromagnetic flowmeter signal converter |
Non-Patent Citations (2)
| Title |
|---|
| 李斌，田才忠.电磁流量计的等效电阻校准原理.自动化仪表19 9.1998,19(9),17-20. |
| 李斌,田才忠.电磁流量计的等效电阻校准原理.自动化仪表19 9.1998,19(9),17-20. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101216339A (en) | 2008-07-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101216339B (en) | Electromagnetic flux converter simulated calibration apparatus | |
| CN100485375C (en) | Portable smart water quality conductive detection device | |
| CN101126624A (en) | Plant leaf parameter measuring instrument | |
| CN101231314A (en) | Method and apparatus for testing magnetosensor resonant frequency elasticity | |
| CN101221057A (en) | On-site bus electromagnetic flowmeter | |
| CN101113934A (en) | Intelligent capacitance differential pressure cell and method | |
| CN104165728A (en) | Pressure controller high in accuracy | |
| CN102322897A (en) | Intelligent slurry density and liquid level integrative analysis instrument and analysis method | |
| CN201402145Y (en) | Analog sensor circuit | |
| CN202256099U (en) | Intelligent slurry density and liquid level comprehensive analyzer | |
| CN101271131A (en) | Synthetic electric power observation and control instrument | |
| CN202648692U (en) | Portable integrated bridge-type sensor calibrating device | |
| CN107490604A (en) | Analyzer of water content and utilization impedance type principle measurement measurement of water ratio method | |
| CN100427893C (en) | Flux measuring method based on negative resistance property and resistance flowmeter | |
| CN101308191B (en) | Diode electrical characteristics test system | |
| CN206097305U (en) | IC -card industry intelligent monitoring gas table controller | |
| CN204008003U (en) | A kind of pin-point accuracy pressure controller | |
| CN201162664Y (en) | Measuring apparatus for oil field oil pumping machine indicating diagram without load sensor | |
| CN103674120B (en) | A kind of compound gas flow metering device and its measuring method based on MEMS sensing elements | |
| CN201373834Y (en) | Online electronic solution concentration meter | |
| CN204461518U (en) | A kind of heating type turbine integral type flowmeter | |
| CN103808453B (en) | There is in bandwidth of operation the electromagnetic exciter of amplitude self-stabilization sine-wave excitation power | |
| CN208350114U (en) | A kind of measurement verification system | |
| CN202453137U (en) | Digital differential pressure transmitter | |
| CN201654521U (en) | PCI bus general mechanical property high-accuracy measurement control system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100811 Termination date: 20190118 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |