CN202793480U - Zero correction device for electromagnetic flowmeter - Google Patents
Zero correction device for electromagnetic flowmeter Download PDFInfo
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- CN202793480U CN202793480U CN201220471422.3U CN201220471422U CN202793480U CN 202793480 U CN202793480 U CN 202793480U CN 201220471422 U CN201220471422 U CN 201220471422U CN 202793480 U CN202793480 U CN 202793480U
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- electromagnetic flowmeter
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Abstract
The utility model discloses a zero correction device for an electromagnetic flowmeter and relates to the technical field of electromagnetic flowmeters. The zero correction device for the electromagnetic flowmeter is used for effectively inhibiting zero offset of the electromagnetic flowmeter, automatically figuring out the offset zero value, and carrying out dynamic correction. According to the zero correction device for the electromagnetic flowmeter, an electrode signal input terminal is connected with a high input impedance meter amplifier, the high input impedance meter amplifier is connected with a second order low pass filter, the second order low pass filter is connected with a direct-current (DC) component separation circuit, the DC component separation circuit is connected with a T-shaped network amplifier, the T-shaped network amplifier is connected with a multichannel sample hold circuit and a scanning circuit, the multichannel sample hold circuit is connected with an analog-to-digital converter, and the analog-to-digital converter is connected with a high-precision reference voltage source. The zero correction device for the electromagnetic flowmeter is mainly applied to electromagnetic flowmeter zero correction technologies.
Description
Technical field
The utility model relates to the electromagnetic flowmeter technical field, relates in particular to a kind of zero point correcting device for electromagnetic flowmeter.
Background technology
Electromagnetic flowmeter is a kind of Ferraris instrument that comes conducting medium volumetric flow rate in the measuring tube according to Faraday's electromagnetic induction law.Adopt microcontroller embedded technology, realized the digital excitation of electromagnetic flowmeter.Electromagnetic flowmeter is widely used in chemical industry, environmental protection, light textile, metallurgy, mine, medicine, papermaking, plumbing, food, industrial technology and the administrative authority such as refines sugar, brewages.
At present, after some problems of electromagnetic flowmeter ubiquity, these problems were mainly manifested in the long-time running of electromagnetic flowmeter instrument, can produce skew zero point, thereby affect measuring accuracy and the stability of electromagnetic flowmeter instrument.The electromagnetic flowmeter instrument of particularly using at metering field, the error in dipping that this zero migration brings, can all produce bad impact to the trade both sides, and the existence of these electromagnetic flowmeter zero migration problems, so that electromagnetic flowmeter in use needs manually regularly to carry out zero point correction, this not only wastes time and energy, and also can increase electromagnetic flowmeter maintenance cost in use.
China Patent Publication No. CN 201653472U, open day is on November 24th, 2010, and name is called in the scheme of " electromagnetic flowmeter " and discloses a kind of electromagnetic flowmeter, and this electromagnetic flowmeter comprises signal processing converter, measuring tube; Electromagnetic flowmeter also comprises electrode structure, electrode structure comprises a coil, an iron core and a pair of potential electrode, coil is placed on the measuring tube, iron core places among the described coil, and be placed on the described measuring tube, a pair of potential electrode is passed from measuring tube and iron core, the medium contact in one end and the measuring tube, other end access signal processing converter.Weak point is that this electromagnetic flowmeter can produce zero migration in use for some time, causes the electromagnetic flowmeter survey precision and stability to descend, and needs artificial timing that electromagnetic flowmeter is carried out zero point and revises, and not only wastes time and energy, and also can increase maintenance cost.
The utility model content
The utility model is can produce zero migration in order to overcome existing electromagnetic flowmeter after long-term the use, the measuring accuracy and the stability decreases that cause the electromagnetic flowmeter instrument, needing artificial timing that electromagnetic flowmeter is carried out zero point revises, not only waste time and energy, also can increase these deficiencies of maintenance cost, the zero migration of a kind of establishment electromagnetic flowmeter is provided, and the value at zero point that can automatically calculate skew, a kind of zero point correcting device for electromagnetic flowmeter of the Mobile state correction of going forward side by side.
To achieve these goals, the utility model is by the following technical solutions:
A kind of zero point correcting device for electromagnetic flowmeter, comprise the high input impedance instrument amplifier, second-order low-pass filter, the DC component separation circuit, T-shaped network amplifier, the multi-channel sampling holding circuit, sweep circuit, analog to digital converter, high-precision reference voltage source and electrode signal input end, the electrode signal input end is connected with the high input impedance instrument amplifier, the high input impedance instrument amplifier is connected with second-order low-pass filter, second-order low-pass filter is connected with the DC component separation circuit, the DC component separation circuit is connected with T-shaped network amplifier, T-shaped network amplifier is connected with the multi-channel sampling holding circuit, T-shaped network amplifier is connected with sweep circuit, the multi-channel sampling holding circuit is connected with analog to digital converter, and analog to digital converter is connected with high-precision reference voltage source.
Electrode signal to electromagnetic flowmeter is processed, by the DC component in the dynamic correction low-frequency ac signal, dispose rational filter factor and enlargement factor, reduce the distortion of the electrode signal that capacitor causes in the circuit, make electrode signal after the processing at utmost near original electrode signal.Electrode signal after processing is carried out secondary separation again, isolate flow signal, undesired signal, zero signal, then secondary separation these three kinds of signals are out sent into analog to digital converter and carry out analog to digital conversion, transfer simulating signal to digital signal.Digital signal is moved, analyzed, calculate real flow signal, and zero signal is compensated.
The utility model can reach following effect:
1, because this scheme can solve the zero migration problem of electromagnetic flowmeter, and can fundamentally improve stability and the measuring accuracy of electromagnetic flowmeter in long-term use procedure, for high-precision metering provides assurance.
2, because the correction at electromagnetic flowmeter zero point, thereby can greatly reduce the lower limit flow velocity of electromagnetic flowmeter survey, the range ability of electromagnetic flowmeter is further enlarged, will further reduce the designing requirement of industrial pipeline.
3, this scheme can be used in the electromagnetic flowmeter of various bores, particularly can be more obvious greater than the large-scale flowmeter effect of 400mm for bore.
4, the electromagnetic flowmeter of this scheme makes Trade Measures more reliable.
5, the electromagnetic flowmeter of this scheme does not need regularly artificial the correction because can be automatically to making amendment zero point, and is not only time saving and energy saving, also can reduce maintenance cost.
Description of drawings
Fig. 1 is that a kind of circuit theory of the present utility model connects block diagram.
Among the figure: 1, high input impedance instrument amplifier; 2, second-order low-pass filter; 3, DC component separation circuit; 4, T-shaped network amplifier; 5, multi-channel sampling holding circuit; 6, sweep circuit; 7, analog to digital converter; 8, high-precision reference voltage source; 9, electrode signal input end.
Embodiment
Below by embodiment, and by reference to the accompanying drawings, the technical solution of the utility model is described in further detail.
Embodiment: a kind of zero point correcting device for electromagnetic flowmeter of present embodiment, as shown in Figure 1, comprise high input impedance instrument amplifier 1, second-order low-pass filter 2, DC component separation circuit 3, T-shaped network amplifier 4, multi-channel sampling holding circuit 5, sweep circuit 6, analog to digital converter 7, high-precision reference voltage source 8 and electrode signal input end 9.
Electrode signal input end 9 is connected with high input impedance instrument amplifier 1, high input impedance instrument amplifier 1 is connected with second-order low-pass filter 2, second-order low-pass filter 2 is connected with DC component separation circuit 3, DC component separation circuit 3 is connected with T-shaped network amplifier 4, T-shaped network amplifier 4 is connected with multi-channel sampling holding circuit 5, T-shaped network amplifier 4 is connected with sweep circuit 6, multi-channel sampling holding circuit 5 is connected with analog to digital converter 7, and analog to digital converter 7 is connected with high-precision reference voltage source 8.
The course of work:
At first, electrode signal is input to high input impedance instrument amplifier 1 by electrode signal input end 9, through the difference of two electrode signals of high input impedance instrument amplifier 1 output, and carries out preliminary amplification; The electrode signal in this time also comprises a part of noise signal, removes noise processed so will be sent to active second-order low-pass filter 2 to electrode signal.
Second step, process second-order low-pass filter 2 is removed the electrode signal after the noise processed, is sent to DC component separation circuit 3 again, and 3 pairs of electrode signals of DC component separation circuit remove the processing of removing the DC component polarizing voltage.Because if do not remove the DC component polarizing voltage, DC component will slowly be assembled, and after T-shaped network amplifier 4 amplifications through the later stage, flow signal will be saturated, the original signal distortion after will making out easily again.And original signal can reduce the distortion rate of original signal greatly by behind the DC component separation circuit 3.
After removing the DC component polarizing voltage, again electrode signal is amplified by T-shaped network amplifier 4.Millivolt electrode signal on the original electrode number is amplified to the hundreds of millivolt.
In the 3rd step, through filtering, every directly, the electrode signal after the amplification can be observed by oscillograph, after seeing that electrode signal is perfectly clear, just each state of electrode signal is separated, and keeps, and then samples.Comprise that the signal to forward, reverse signal, the signal of zero condition separate, keep.Then sampling.And respectively the simulating signal of each state being sent to analog to digital converter 7, the analog signal conversion that makes each state is corresponding digital signal.
The 4th step, electrode signal after T-shaped network amplifier 4 amplifications is carried out sweep record by electrode state sweep circuit 6, the state of analyzing electrode, comprise empty pipe condition, the electrode off-state, electric pole short circuit state, the electrode class of impedance over the ground, 50Hz disturbance state etc. is carried out a series of diagnostic work.
The 5th step, the data-signal that obtains from the 3rd step is carried out each state analysis, comprise forward signal, reverse signal also has the electrode signal under the zero condition.
Wherein, flow signal value=forward signal value-reverse signal value-zero condition signal off-set value-50Hz phase pushing figure.
By the processing of hardware circuit, cooperate software algorithm at last, the value of real flow signal and zero migration is separated, so that flow measurements more accurately and reliably.
The above has described embodiment of the present utility model by reference to the accompanying drawings, but not limited by above-described embodiment when realizing, those of ordinary skills can make a variety of changes or revise within the scope of the appended claims.
Claims (1)
1. zero point correcting device that is used for electromagnetic flowmeter, it is characterized in that, comprise high input impedance instrument amplifier (1), second-order low-pass filter (2), DC component separation circuit (3), T-shaped network amplifier (4), multi-channel sampling holding circuit (5), sweep circuit (6), analog to digital converter (7), high-precision reference voltage source (8) and electrode signal input end (9), electrode signal input end (9) is connected with high input impedance instrument amplifier (1), high input impedance instrument amplifier (1) is connected with second-order low-pass filter (2), second-order low-pass filter (2) is connected with DC component separation circuit (3), DC component separation circuit (3) is connected with T-shaped network amplifier (4), T-shaped network amplifier (4) is connected with multi-channel sampling holding circuit (5), T-shaped network amplifier (4) is connected with sweep circuit (6), multi-channel sampling holding circuit (5) is connected with analog to digital converter (7), and analog to digital converter (7) is connected with high-precision reference voltage source (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220471422.3U CN202793480U (en) | 2012-09-17 | 2012-09-17 | Zero correction device for electromagnetic flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220471422.3U CN202793480U (en) | 2012-09-17 | 2012-09-17 | Zero correction device for electromagnetic flowmeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202793480U true CN202793480U (en) | 2013-03-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201220471422.3U Expired - Lifetime CN202793480U (en) | 2012-09-17 | 2012-09-17 | Zero correction device for electromagnetic flowmeter |
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| Country | Link |
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| CN (1) | CN202793480U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107462782A (en) * | 2016-06-02 | 2017-12-12 | 镇江腾龙智能科技有限公司 | Streaming potential on-line measurement instrument definitely designs with relative detection signal |
| CN108645489A (en) * | 2018-04-27 | 2018-10-12 | 重庆川仪自动化股份有限公司 | A kind of quick zero point compensation method of electromagnetic flow-measurement |
-
2012
- 2012-09-17 CN CN201220471422.3U patent/CN202793480U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107462782A (en) * | 2016-06-02 | 2017-12-12 | 镇江腾龙智能科技有限公司 | Streaming potential on-line measurement instrument definitely designs with relative detection signal |
| CN108645489A (en) * | 2018-04-27 | 2018-10-12 | 重庆川仪自动化股份有限公司 | A kind of quick zero point compensation method of electromagnetic flow-measurement |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130313 |