CN2781399Y

CN2781399Y - Chopper decoupling device for induced polarization measuring

Info

Publication number: CN2781399Y
Application number: CN 200520050235
Authority: CN
Inventors: 何继善
Original assignee: JISHAN HIGH TECH Co Ltd HUNAN PROV
Current assignee: JISHAN HIGH TECH Co Ltd HUNAN PROV
Priority date: 2005-02-01
Filing date: 2005-02-01
Publication date: 2006-05-17
Anticipated expiration: 2015-02-01

Abstract

The utility model discloses a chopper decoupling device which overcomes the effects from electromagnetic induction coupling in induced polarization measurement. The device is an SCM or a multi-grade delay switch which is controlled by a transistor trigger, and is arranged on the front part or the rear part of a preamplifier in the existing induced polarization receiver. The device has the advantages of wide frequency, high precision, delay time width and delay time ratio of multi-grade selection. After the device is used, the utility model has the advantages of induced polarization measurement precision enhancement, observation speed acceleration, field work time shorten, labour intensity reduction and low cost, and the aims of raising work efficiency and economic benefit are achieved.

Description

Chopping decoupler with exciting polarizing measurement

Technical field

The utility model relates to a kind of chopping decoupler with exciting polarizing measurement, especially relates to a kind of copped wave decoupling device that overcomes the electromagnetic induction coupling effect in the geophysics induced-polarization measurement of reconnoitring.

Background technology

Induced-polarization measurement is a kind of applied geophysics method of reconnoitring mineral resources and other buried target, and it measures the induced polarization potential difference (PD) that these targets cause.Fig. 1 is rectangle current waveform figure commonly used in the induced-polarization measurement.In this measurement, can run into inevitably by underground current change in time and cause do not belong to the induced polarization category and with subsurface material electrically and the potential difference (PD) that causes of the relevant galvanomagnetic effect of the apparatus and method of measuring, thereby the measurement to induced polarization causes interference, obscured the induced polarization information that to extract, make it not reach the geological effect of expection, on the specialty this phenomenon is called " induction coupling ".The essence of galvanomagnetic effect is that the magnetic field of electric current and its generation changes the physical phenomenon that is referred to as electromagnetic induction that causes in time.For waveform shown in Figure 1, electromagnetic induction occurs in the rectangle electric current switches on and off, and makes dI/dt ≠ 0, thereby in the period of dB/dt ≠ 0, on the waveform that observes, show as a series of poops that appear at rectangle electric current rising edge and negative edge, as shown in phantom in Figure 2.

And keep the constant period at the rectangle electric current, because dI/dt=0 (thereby dB/dt=0), the potential difference (PD) that electromagnetic induction causes decays to 0 rapidly.The electrical properties of height of spike pulse (intensity) and rate of decay (thereby time of pulse persistance) and underground medium, the locus of point of measuring potential difference (PD) are relevant.Underground electric conductivity is good more, and when the point of measurement potential difference (PD) was positioned at the middle part of two galvanic electrodes, the influence of electromagnetic induction coupling was obvious more.

The potential difference (PD) information that induced polarization will be extracted, as shown in Figure 2; When exciting with rectangle electric current shown in Figure 1 or accurate rectangle electric current, keep constant at electric current, as yet the period that does not disconnect, it increases along with the lasting time lengthening of electric current, reaches capacity gradually.And the period after the rectangle electric current disconnects, it shows as in time decay gradually, the final disappearance.

Fig. 2 shows, the potential difference (PD) that the electromagnetic induction coupling causes with the potential difference (PD) that induced polarization produces, coexists as in the potential difference (PD) waveform that the induced polarization receiver receives, and electromagnetic induction has caused tangible interference to the measurement of induced polarization.

The existing method that overcomes the electromagnetic induction coupling is to postpone the time of measuring the induced polarization potential difference (PD), perhaps reduce the frequency of sending into the electric current in the ground, to reduce the influence of electromagnetic coupled, but do the interference that to avoid the electromagnetic induction coupling fully like this, simultaneously can lose needed induced polarization information again, this loss remains serious sometimes; Also the someone proposes to proofread and correct above-mentioned influence by the way of multi-frequency measurement or indoor calculating, but this way can not directly, fully be removed above-mentioned influence, will increase field and/or office work amount on the contrary, and is neither easy, also uneconomical.

The utility model content

The purpose of this utility model is to overcome the existing electromagnetic coupled of eliminating influences the defective that method exists, a kind of influence that can directly, substantially fully overcome the electromagnetic induction coupling is provided, simultaneously can keep the information of induced polarization substantially again, and not increase the chopping decoupler with exciting polarizing measurement of field or office work amount.

The technical solution of the utility model is as follows:

The utility model copped wave decoupling device is one by Single-chip Controlling, and frequency range is from 0.01Hz to 100Hz, and copped wave width Delta t was from 0 second to 10 seconds, and copped wave is than Q from 0 to the 3/4 continuously adjustable grade delay switch that manys; The shelves number of many grades of delay switchs is at least 3 grades, and preferred version is the 5-10 shelves.The utility model copped wave decoupling device can be installed on after the prime amplifier of existing frequency field induced polarization receiver.Its principle of work is, the synchronous signal of electric current is obtained and sent to single-chip microcomputer from the input signal through preposition amplification, frequency according to synchronizing signal, single-chip microcomputer is adjusted the own frequency of operation of controlling (make it with send power frequency identical), and send instruction to delay switch, delay switch is postponed the time of connecting the next stage input according to instruction, reaches the purpose of copped wave decoupling.

The utility model copped wave decoupling device also can be made of transistor flip-flop and many grades of delay switchs, promptly replaces single-chip microcomputer with transistor flip-flop.

The power of electromagnetic induction coupling and the time according to specific time and site of effect and different.

Through after the copped wave, make each beginning part of rectangle or accurate rectangle forward or backwards in the waveform input signal of Fig. 1 and/or Fig. 2, " cut " all that to remove a time width be the part of Δ t, become waveform shown in Figure 4.

Through copped wave, waveform shown in Figure 4, compare with the waveform of input, removed the forward at the current-jump place that is positioned at each rectangle of Fig. 2 that causes by the electromagnetic induction coupling effect or the poop of negative sense." cut " the time width Δ t that goes and rectangle width T/2 (or the T of former transmission electric current _h/ 2) ratio, the utility model are defined as the copped wave ratio, represent with alphabetical Q.Q=2 Δ t/T (or 2 Δ t/T _h).

Δ t or copped wave can be adopted interactive mode according to the feature and the degree of the suffered measurement electromagnetic induction of induced polarization coupling effect than Q, are provided with in advance or adjust afterwards.Reach the purpose of not only removing the electromagnetic induction coupling but also keeping induced polarization information.

The copped wave decoupling device of the utility model also can place the signal input part of existing induced polarization receiver, before the prime amplifier.

The copped wave decoupling device of the utility model has very wide frequency range, the various frequencies that can be fit to use in the induced-polarization measurement; Has very high sensitivity, the very faint signal that can be fit to run in the induced-polarization measurement; The various waveforms that can be suitable for running in the induced-polarization measurement, these waveforms are the different square waves that are superimposed with the electromagnetic induction coupling in various degree and the effect of induced polarization of different powers, the bipolarity square wave that comprises interruption, continuous bipolarity square wave, double frequency constant amplitude rectangle composite wave etc.; Has broad delay selection function; Can overcome the influence that various different strong and weak electromagnetic induction are coupled, be suitable for different various areas and the various geological tasks of the electric condition in ground; Have very high copped wave precision, can carry out copped wave, neither can make residual electromagnetic induction coupling excessive, also can not make the induced polarization information of loss too much according to the copped wave width of setting.

Utilize the copped wave device of the utility model, can improve the precision of open-air induced-polarization measurement, accelerate its observation speed, shorten the field work time, reduce labor intensity, reduce and measure cost, increase work efficiency and economic benefit.

Description of drawings

Fig. 1 is current waveform figure commonly used in the induced-polarization measurement;

Fig. 2 is coupling in display form figure on the induced-polarization measurement waveform for electromagnetic induction;

Fig. 3 is that the utility model copped wave decoupling device is installed on the position view in the induced-polarization measurement receiver:

(a) be positioned at after the prime amplifier, (b) be positioned at before the prime amplifier;

Fig. 4 cuts the later oscillogram of electromagnetic induction coupling;

Fig. 5 is the block scheme of the utility model one embodiment;

Fig. 6 is a kind of circuit theory diagrams embodiment illustrated in fig. 5;

Fig. 7 is the block scheme of another embodiment of the utility model.

Embodiment

The utility model is described in further detail below in conjunction with embodiment.

Embodiment 1

Referring to Fig. 5.Present embodiment copped wave decoupling device is made of transistor flip-flop 2 and many grades of delay switchs 3.The input seismic electrical signal that existing induced-polarization measurement receiver receives is after its prime amplifier 4 amplifies, via K switch ₁, K ₂Enter the utility model present embodiment copped wave decoupling device that constitutes by

trigger

2 and 5 retaining delay switchs 3.Trigger is obtained synchronizing signal by isolator 1, many grades of delay switchs of the State Control of trigger 23, to synchronously carrying out copped wave through the input signal that amplifies, make without waveform shown in Figure 2 copped wave, that contain the electromagnetic induction coupling effect and become the waveform shown in Figure 4 that does not contain the electromagnetic induction coupling effect after the copped wave, and this waveform offered frequency divider 5, thereby reach the purpose of copped wave decoupling.Seriously be enough to influence the area of induced polarization observed result, K switch in electromagnetic induction coupling ₁, K ₂Receive contact 6,9, insert the copped wave decoupling device; And slight at the induction coupling influence, negligible area, K switch ₁, K ₂Receive contact 7,8, signal directly enters the frequency divider 5 in the existing induced-polarization measurement receiver without the copped wave decoupling device.

Fig. 6 is an a kind of concrete circuit embodiment illustrated in fig. 5, comprises trigger 2 circuit and many retaining delay switch 3 circuit two parts.Via transistor BG ₁Synchronizing signal control NAND gate circuit YF ₁-YF ₃Reach the conducting of the monostable trigger of some resistance R, capacitor C composition, monostable trigger oxide-semiconductor control transistors BG ₁-BG ₂Reach 5 break-makes of keeping off delay switchs that related elements constitutes, reach the effect of copped wave decoupling.K switch ₁, K ₂Also work insert/not insert the copped wave decoupling device.

The present embodiment frequency range from 0.01Hz arrives 100Hz, copped wave width Delta t were from 0 second to 10 seconds, and copped wave is more adjustable continuously than Q from 0 to 3/4.

Embodiment 2

Difference referring to accompanying drawing 7 present embodiments and embodiment 1 is that the single-chip microcomputer 10 of selecting for use integrated circuit to constitute replaces transistor flip-flop, and other constitutes with embodiment 1.Principle of work is also with embodiment 1.Synchronizing signal is passed to single-chip microcomputer 10 through isolator 1, and single-chip microcomputer 10 controls keep off delay switchs 3 more, finish the task of copped wave decoupling.

When needing the copped wave decoupling, K switch ₁, K ₂Insert the copped wave decoupling device, then do not insert when not required.

Claims

1, a kind of chopping decoupler with exciting polarizing measurement is characterized in that, it is made of monolithic processor controlled many grades of delay switchs, and the shelves number of described many grades of delay switchs is at least 3 grades.

2, chopping decoupler with exciting polarizing measurement according to claim 1 is characterized in that, described many grades of delay switchs are the 5-10 shelves.

3, a kind of chopping decoupler with exciting polarizing measurement is characterized in that, it is made of many grades of delay switchs of transistor flip-flop control, and the shelves number of described many grades of delay switchs is at least 3 grades.

4, chopping decoupler with exciting polarizing measurement according to claim 3 is characterized in that, described many grades of delay switchs are the 5-10 shelves.