CN204202661U - A kind of application double excitation formula electromagnetic flowmeter - Google Patents

Abstract

The utility model discloses a kind of application double excitation formula electromagnetic flowmeter, comprise: magnetizing coil, magnetizer, electrode, signal processing circuit, A/D converter, microprocessor, magnetizer of the present utility model provides exciting curent with two different excitation cycles to described magnetizing coil, and the excitation cycle selectivity of two is changed, the initial flow signal of two magnet excitation frequencies can be obtained, effectively can eliminate the measuring error because induced noise causes, and the zero point of not carrying out causing the flowing of stopping fluid adjusting and improves measuring accuracy, and reliability is high.

Description

A kind of application double excitation formula electromagnetic flowmeter

Technical field

The utility model relates to a kind of application double excitation formula electromagnetic flowmeter.

Background technology

Weighting function of electromagnetic flowmeter is an imaginary physical quantity, and its physical meaning is: during electromagnetic flowmeter work, measure each point produces in pipeline section space induction electromotive force to output voltage between electrode make the size contributed.Scientists has made clear and definite definition to the numerical values recited of certain some weighting function in measuring pipe of electromagnetic flow meter section space, that is: when unitary current flows through two electrodes, during composition current loop, and the size of this current density.Therefore, also there are many documents that weighting function is referred to as empty electric current, and the measuring system of electromagnetic flowmeter is namely for by this Current calculation flow, but current electromagnetic flowmeter is all the excitation cycles adopting the fixed cycle, therefore each obtained data on flows is all based on this excitation cycle, the reliability of measurement is not high.

Summary of the invention

In order to overcome the deficiencies in the prior art, the utility model provides a kind of application double excitation formula electromagnetic flowmeter.

The utility model solves the technical scheme that its technical matters adopts:

A kind of application double excitation formula electromagnetic flowmeter, comprising:

Be arranged on the magnetizing coil measuring the upper and lower both sides of pipe fitting, this magnetizing coil provides magnetic field to described measuring tube inside;

Magnetizer, this magnetizer is connected with magnetizing coil, and provides exciting curent with two different excitation cycles to described magnetizing coil;

Electrode, this electrode is arranged on measures the pipe fitting left and right sides, the electric current produced for detecting flow cutting magnetic line in measurement pipe fitting;

Signal processing circuit, this signal processing circuit and Electrode connection, for the treatment of the current signal detected by electrode;

A/D converter, this A/D converter is connected with signal processing circuit, for being digital signal by analog-signal transitions;

Microprocessor, this microprocessor is connected with A/D converter, when being used for producing electromotive force in excitation cycle when between described electrode often kind described, according to the described electromotive force extrapolation flow signal produced during described excitation cycle, this microprocessor is also connected with magnetizer, to switch different excitation cycles.

Described microprocessor carries out extrapolation computing according to the linear function of excitation cycle.

Described signal processing circuit comprises amplifying circuit, filtering circuit, and signal exports successively after amplifying circuit, filtering circuit.

Also comprise a display, this display is connected with microprocessor.

Described microprocessor is preferably the MSP430 single-chip microcomputer of Hong Kong TI company or Dutch PHILIPS company 80C552 single-chip microcomputer.

The beneficial effects of the utility model are: magnetizer of the present utility model provides exciting curent with two different excitation cycles to described magnetizing coil, and the excitation cycle selectivity of two is changed, the initial flow signal of two magnet excitation frequencies can be obtained, effectively can eliminate the measuring error because induced noise causes, and improve measuring accuracy, and reliability is high.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the utility model is further illustrated.

Fig. 1 is structure principle chart of the present utility model.

Embodiment

With reference to the structure principle chart that Fig. 1, Fig. 1 are the utility model specific embodiments, as shown in the figure, 1 one kinds of application double excitation formula electromagnetic flowmeters, comprising:

Be arranged on the magnetizing coil 2 measuring the upper and lower both sides of pipe fitting, this magnetizing coil 2 provides magnetic field to described measuring tube inside;

Magnetizer, this magnetizer is connected with magnetizing coil, and provides exciting curent with two different excitation cycles to described magnetizing coil;

Electrode 1, this electrode 1 is arranged on measures the pipe fitting left and right sides, the electric current produced for detecting flow cutting magnetic line in measurement pipe fitting;

Signal processing circuit, this signal processing circuit is connected with electrode 1, for the treatment of the current signal detected by electrode 1;

A/D converter, this A/D converter is connected with signal processing circuit, for being digital signal by analog-signal transitions;

Microprocessor, this microprocessor is connected with A/D converter, when being used for producing electromotive force in excitation cycle when between described electrode often kind described, according to the described electromotive force extrapolation flow signal produced during described excitation cycle, this microprocessor is also connected with magnetizer, to switch different excitation cycles.

Magnetizer of the present utility model provides exciting curent with two different excitation cycles to described magnetizing coil 2, and the excitation cycle selectivity of two is changed, the initial flow signal of two magnet excitation frequencies can be obtained, effectively can eliminate the measuring error because induced noise causes, and improve measuring accuracy, and reliability is high.

Further, described signal processing circuit comprises amplifying circuit, filtering circuit, signal exports successively after amplifying circuit, filtering circuit, namely filtering circuit carries out filtering to the output of signal amplification circuit, reduce the impact of interference noise, obtain the first-harmonic of flow velocity signal, and make the power of multiple interference noise reduce with bandwidth and reduce, improve signal to noise ratio (S/N ratio), improve the measuring accuracy of electromagnetic flowmeter.

As preferably, described microprocessor is preferably the MSP430 single-chip microcomputer of Hong Kong TI company or Dutch PHILIPS company 80C552 single-chip microcomputer, and described microprocessor is also connected with a display, to show flow measurement result.

As preferably, described microprocessor carries out extrapolation computing according to the linear function of excitation cycle.

Above better enforcement of the present utility model is illustrated; certainly; the utility model can also adopt form different from the embodiment described above; the equivalent conversion that those of ordinary skill in the art do under the prerequisite without prejudice to spirit of the present invention or change accordingly, all should belong in protection domain of the present utility model.

Claims (1)

1. apply a double excitation formula electromagnetic flowmeter, it is characterized in that: comprising:

Be arranged on the magnetizing coil (2) measuring the upper and lower both sides of pipe fitting, this magnetizing coil (2) provides magnetic field to described measuring tube inside;

Magnetizer, this magnetizer is connected with magnetizing coil, and provides exciting curent with two different excitation cycles to described magnetizing coil;

Electrode (1), this electrode (1) is arranged on measures the pipe fitting left and right sides, the electric current produced for detecting flow cutting magnetic line in measurement pipe fitting;

Signal processing circuit, this signal processing circuit is connected with electrode (1), for the treatment of the current signal detected by electrode (1);

A/D converter, this A/D converter is connected with signal processing circuit, for being digital signal by analog-signal transitions;

Microprocessor, this microprocessor is connected with A/D converter, when being used for producing electromotive force in excitation cycle when between described electrode often kind described, according to the described electromotive force extrapolation flow signal produced during described excitation cycle, this microprocessor is also connected with magnetizer, to switch different excitation cycles.