CN103713021A - Detecting method and device with impedance type water content sensor - Google Patents

Abstract

The invention discloses a detecting method and device with an impedance type water content sensor. The device comprises a reference circuit, a symmetric bipolar voltage generation circuit, a high-frequency alternating current excitation signal generation circuit, a power amplification circuit, a discharging circuit, an effective value circuit and a micro control circuit. The device is simple in structure and convenient to install. According to the method and the device, the overall measurement accuracy of the impedance type water content sensor can be remarkably improved.

Description

Impedance type moisture sensor detection method and pick-up unit

Technical field

The present invention relates to a kind of impedance type moisture sensor detection method and pick-up unit.

Background technology

Crude oil water content is the significant data in crude production, the important parameter index of research oil-field development situation, in crude production and storage and transport process, the detection of crude oil water content is very important, directly affect that crude oil production, dehydration, collection are defeated, sale, refinement etc., affect quality and the cost of development of crude oil, Fig. 7 is the structural drawing of impedance type moisture sensor, impedance type moisture sensor has four electrodes, i.e. two exciting electrodes and two potential electrode.

Current impedance type watercutmeter is because pumping signal is not strict symmetry, so long-term work exists charge accumulated, can form error.This novel MSP430 series monolithic that utilizes, for information processing core, exchanges symmetrical drive signal for impedance sensor provides, and the positive and negative exciting electrode timing short circuit of control group formula sensor, realizes the stored charge electric discharge on exciting electrode.This device can significantly improve the overall measurement accuracy of impedance type moisture sensor.

Summary of the invention

Technical matters to be solved by this invention is, overcomes the shortcoming of prior art, provides a kind of structure simple and direct, easy for installation, and can significantly improve impedance type moisture sensor detection method and the pick-up unit of the overall measurement accuracy of impedance type moisture sensor.

In order to solve above technical matters, the invention provides a kind of impedance type moisture sensor detection method, the method realizes by the exciting electrode two ends access driving voltage at impedance type moisture sensor, comprises following concrete steps:

Step (1): 5V analog voltage y is provided ₀, by 5V analog voltage y ₀carry out voltage stabilizing processing and obtain reference voltage y ₁, and y ₁=4.096v;

Step (2): by the y in step (1) ₁according to following formula, be converted to the double-channel output signal of strict symmetry:

$\left\{\begin{array}{c}{y}_2=-y_1\×R_3/R_4\\ y_3=y_1\×R_3/R_4\end{array}\right.$

Wherein, y ₂be defined as the negative voltage signal of strict symmetry, y ₃be defined as the positive voltage signal of strict symmetry, R ₃be defined as the first gain resistor, R ₄be defined as the second gain resistor;

Step (3): by the y obtaining in step (2) ₂and y ₃according to following formula, be converted into the adjustable symmetric double polar voltages signal y of frequency ₄,

y ₄=(1-k)×y ₃+k×y ₂

Wherein, the height that k is defined as high frequency output replaces level, k=0 or 1; And k=0 time lasting with k=1 is identical;

Step (4): by the adjustable symmetric double polar voltages signal y of the frequency obtaining in step (3) ₄according to following formula, carry out obtaining high power AC voltage signal y after power amplification ₅:

Y ₅=(1-k) * y ₃+ k * y ₂, y ₅peak power be:

P=200mA×|y ₅|=200mA×4.096×R ₃/R ₄=0.8192×R ₃/R ₄；

Step (5): by the high power AC voltage signal y in step (4) ₅according to following formula, be converted to ac-excited voltage signal y ₆:

y ₆=[(1-k)×y ₃+k×y ₂]×k ₁

Wherein, k ₁be defined as electric discharge output level, and k ₁=0 or 1, k ₁within=0 o'clock, be discharge condition, k ₁=0 and k ₁=1 alternately occurs, k ₁each lasting time of=0 state is identical, k ₁each lasting time of=1 state is also identical, k ₁=1 each lasting time was compared k ₁=0 each lasting time is long;

Step (6): by the ac-excited voltage signal y obtaining in step (5) ₆the exciting electrode two ends of termination formula moisture sensor, when fluid flows through and k in sensor ₁=1 o'clock, potential electrode two ends output AC voltage signal y ₇, y ₇expression formula be:

y ₇=w×y ₆=w×[(1-k)×y ₃+k×y ₂]

Wherein, w is defined as water percentage and characterizes coefficient;

Step (7): by the ac voltage signal y obtaining in step (6) ₇be converted to direct current signal y ₈, measure y ₈and calculate water percentage sign coefficient w by following formula batch total:

$\left\{\begin{array}{c}{y}_8=w\×(y_3+|y_2\left|\right)/2\\ w=2\×y_8/(y_3+|y_2\left|\right)\end{array}\right..$

Technique effect: in the present invention, remain the signal of strict symmetry, thereby can be on the positive and negative exciting electrode of impedance type moisture sensor incoming transport driving voltage signal y ₆, realized regularly short circuit of the positive and negative exciting electrode of control group formula moisture sensor, realize the stored charge electric discharge on its exciting electrode, this measuring method significantly improves the overall measurement accuracy of impedance type moisture sensor.

The present invention has also designed a kind of impedance type moisture sensor pick-up unit, comprise that reference circuit, symmetric double polar voltages produce circuit, high-frequency AC excitation signal produces circuit, power amplification circuit, discharge circuit, true rms circuit and micro-control circuit, wherein:

Reference circuit is used for 5V analog voltage y ₀carry out voltage stabilizing processing and obtain reference voltage y ₁;

Symmetric double polar voltages produce circuit under the control of micro-control circuit by y ₁be transformed into the double-channel output signal y of strict symmetry ₂and y ₃, wherein, y ₂be defined as the negative voltage signal of strict symmetry, y ₃be defined as the positive voltage signal of strict symmetry;

High-frequency AC excitation signal produce circuit under the control of micro-control circuit by y ₂and y ₃be converted to the adjustable symmetric double polar voltages signal y of frequency ₄;

Power amplification circuit is by the adjustable symmetric double polar voltages signal y of frequency ₄carry out obtaining high power AC voltage signal y after power amplification ₅, and be converted to ac-excited voltage signal y through discharge circuit ₆, ac-excited voltage signal y ₆the exciting electrode two ends of termination formula moisture sensor;

When fluid is when flowing through in sensor, the potential electrode two ends output AC voltage signal y of impedance type moisture sensor ₇, y ₇after true rms circuit, be converted to water percentage characterize coefficient w relevant be converted to direct current signal y ₈;

Micro-control circuit receives direct current signal y ₈, and record water percentage sign coefficient w.

Technique effect: impedance type moisture sensor pick-up unit provided by the present invention applies pumping signal between two exciting electrodes of impedance sensor, when fluid is when flowing through in sensor, existence due to impedance between potential electrode, known according to electrical principles, between potential electrode, produce voltage, this voltage is directly proportional to the oil-water media impedance by pipeline road, and water percentage wherein is directly depended in oil-water media impedance, therefore subsequent conditioning circuit is easy to obtain crude oil water content according to this voltage, its obvious advantage is not only to measure accurately, and structure is simple and direct, easy for installation,

Yet current impedance type watercutmeter is because pumping signal is not strict symmetry, therefore there is charge accumulated in long-term work, can form error, the present invention utilizes MSP430 series monolithic for information processing core, for providing, impedance sensor exchanges symmetrical drive signal, and the positive and negative exciting electrode timing short circuit of control group formula sensor, realize the stored charge electric discharge on exciting electrode, this device can significantly improve the overall measurement accuracy of impedance type moisture sensor.

Accompanying drawing explanation

The structured flowchart of the impedance type moisture sensor pick-up unit that Fig. 1 the present invention is designed;

Fig. 2 is the circuit diagram of micro-control circuit in the present invention;

The circuit diagram of reference circuit in Fig. 3 the present invention;

In Fig. 4 the present invention, symmetric double polar voltages produces the circuit diagram of circuit;

The circuit diagram of the ac-excited signal generating circuit of Fig. 5 medium-high frequency of the present invention;

The circuit diagram of power amplification circuit in Fig. 6 the present invention;

Fig. 7 is the structural drawing of impedance type moisture sensor;

The circuit diagram of true rms circuit in Fig. 8 the present invention;

The circuit diagram of discharge circuit in Fig. 9 the present invention.

Embodiment

Embodiment 1

A kind of impedance type moisture sensor detection method that the present embodiment provides, the method realizes by the exciting electrode two ends access driving voltage at impedance type moisture sensor, comprises following concrete steps:

Step (1): 5V analog voltage y is provided ₀, by 5V analog voltage y ₀carry out voltage stabilizing processing and obtain reference voltage y ₁, and y ₁=4.096v;

Step (2): by the y in step (1) ₁according to following formula, be converted to the double-channel output signal of strict symmetry:

$\left\{\begin{array}{c}{y}_2=-y_1\×R_3/R_4\\ y_3=y_1\×R_3/R_4\end{array}\right.$

Wherein, y ₂be defined as the negative voltage signal of strict symmetry, y ₃be defined as the positive voltage signal of strict symmetry, R ₃be defined as the first gain resistor, R ₄be defined as the second gain resistor;

Step (3): by the y obtaining in step (2) ₂and y ₃according to following formula, be converted into the adjustable symmetric double polar voltages signal y of frequency ₄,

y ₄=(1-k)×y ₃+k×y ₂

Wherein, the height that k is defined as high frequency output replaces level, k=0 or 1; And k=0 time lasting with k=1 is identical;

Step (4): by the adjustable symmetric double polar voltages signal y of the frequency obtaining in step (3) ₄according to following formula, carry out obtaining high power AC voltage signal y after power amplification ₅:

Y ₅=(1-k) * y ₃+ k * y ₂, y ₅peak power be:

P=200mA×|y ₅|=200mA×4.096×R ₃/R ₄=0.8192×R ₃/R ₄；

Step (5): by the high power AC voltage signal y in step (4) ₅according to following formula, be converted to ac-excited voltage signal y ₆:

y ₆=[(1-k)×y ₃+k×y ₂]×k ₁

Wherein, k ₁be defined as electric discharge output level, and k ₁=0 or 1, k ₁within=0 o'clock, be discharge condition, k ₁=0 and k ₁=1 alternately occurs, k ₁each lasting time of=0 state is identical, k ₁each lasting time of=1 state is also identical, k ₁=1 each lasting time was compared k ₁=0 each lasting time is long;

Step (6): by the ac-excited voltage signal y obtaining in step (5) ₆the exciting electrode two ends of termination formula moisture sensor, when fluid flows through and k in sensor ₁=1 o'clock, potential electrode two ends output AC voltage signal y ₇, y ₇expression formula be:

y ₇=w×y ₆=w×[(1-k)×y ₃+k×y ₂]

Wherein, w is defined as water percentage and characterizes coefficient;

Step (7): by the ac voltage signal y obtaining in step (6) ₇be converted to direct current signal y ₈, measure y ₈and calculate water percentage sign coefficient w by following formula batch total:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="8"\; label="y"\; filenames="HDA0000453758920000021.png,HDA0000453758920000032.png"\; state="\{\{state\}\}">y</figure-callout>}}_8=w\&times;({\mathrm{<figure-callout\; id="3"\; label="y"\; filenames="HDA0000453758920000021.png,HDA0000453758920000022.png"\; state="\{\{state\}\}">y</figure-callout>}}_3+|{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000453758920000021.png,HDA0000453758920000022.png"\; state="\{\{state\}\}">y</figure-callout>}}_2\left|\right)/2\\ w=2\&times;{\mathrm{<figure-callout\; id="8"\; label="y"\; filenames="HDA0000453758920000021.png,HDA0000453758920000032.png"\; state="\{\{state\}\}">y</figure-callout>}}_8/({\mathrm{<figure-callout\; id="3"\; label="y"\; filenames="HDA0000453758920000021.png,HDA0000453758920000022.png"\; state="\{\{state\}\}">y</figure-callout>}}_3+|{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000453758920000021.png,HDA0000453758920000022.png"\; state="\{\{state\}\}">y</figure-callout>}}_2\left|\right)\end{array}\right..$

Embodiment 2

As shown in Figure 1, the present embodiment provides a kind of impedance type moisture sensor pick-up unit, comprise that reference circuit, symmetric double polar voltages produce circuit, high-frequency AC excitation signal produces circuit, power amplification circuit, discharge circuit, true rms circuit and micro-control circuit, wherein:

Reference circuit is used for 5V analog voltage y ₀carry out voltage stabilizing processing and obtain reference voltage y ₁;

Symmetric double polar voltages produce circuit under the control of micro-control circuit by y ₁be transformed into the double-channel output signal y of strict symmetry ₂and y ₃, wherein, y ₂be defined as the negative voltage signal of strict symmetry, y ₃be defined as the positive voltage signal of strict symmetry;

High-frequency AC excitation signal produce circuit under the control of micro-control circuit by y ₂and y ₃be converted to the adjustable symmetric double polar voltages signal y of frequency ₄;

Power amplification circuit is by the adjustable symmetric double polar voltages signal y of frequency ₄carry out obtaining high power AC voltage signal y after power amplification ₅, and be converted to ac-excited voltage signal y through discharge circuit ₆, ac-excited voltage signal y ₆the exciting electrode two ends of termination formula moisture sensor;

When fluid is when flowing through in sensor, the potential electrode two ends output AC voltage signal y of impedance type moisture sensor ₇, y ₇after true rms circuit, be converted to water percentage characterize coefficient w relevant be converted to direct current signal y ₈;

Micro-control circuit receives direct current signal y ₈, and record water percentage sign coefficient w.

Fig. 2 is the circuit diagram of micro-control circuit, and the chip of selecting is that MSP430F2111 is U1, also comprises by resistance electric capacity, the reset circuit that diode forms;

Fig. 3 is the circuit diagram of reference circuit, by REF3140-4.096 chip, is mainly that U2 and electric capacity form;

Fig. 4 is the circuit diagram that symmetric double polar voltages produces circuit, and mainly by three LM358 amplifiers, U3, U4A, U4B and electric capacity and resistance form;

Fig. 5 is the circuit diagram that high-frequency AC excitation signal produces circuit, by the multinomial analog switch of MAX4051AESE, is mainly that U5, electric capacity and resistance form;

Fig. 6 is the circuit diagram of power amplification circuit, by OPA551FA power amplifier, is mainly that U6, electric capacity and resistance form;

Fig. 8 is the circuit diagram of true rms circuit, by AD620AR-S08 instrument amplifier, is mainly that U7, effective value chip AD637BR are that U8, resistance and electric capacity etc. form;

Fig. 9 is the circuit diagram of discharge circuit, mainly resistance, diode, relay and triode, consists of;

The high frequency control port of MSP430F2111 chip is connected with the ADDA end of the multinomial analog switch of MAX4051AESE in Fig. 5, and micro-control circuit regularly produces interruption, controls high-frequency AC excitation signal and produces the adjustable symmetric double polar voltages signal of circuit generation frequency; The control of discharge port of MSP430F2111 chip is connected with R14 with R13 in Fig. 9 respectively, controlled discharge circuit timing discharging;

The control of discharge port of MSP430F2111 chip is connected with R14 with R13 in Fig. 9 respectively, when the control of discharge port of MSP430F2111 chip is exported a high level, triode Q1 conducting, relay power adhesive by reed with digitally join, now the exciting electrode of impedance type moisture sensor anodal with negative pole short circuit, realize unnecessary charge discharge, when the control of discharge port of MSP430F2111 chip is exported a low level, triode Q1 blocks relay electric-loss, reed rebounds, and now exciting electrode is normally worked;

REF3140-4.096 chip input AVDD is 5V voltage, and after REF3140-4.096 chip is processed, by Vout end output reference voltage, magnitude of voltage is 4.096v;

The REF-IN end of reference voltage access U3, forms voltage follower circuit, follows the positive input terminal that voltage directly accesses U4A, accesses the negative input end of U4B after a resistance again, and U4B is by the voltage of REF-OUT (+) output+4.096v; And U4A is by the voltage of REF-OUT (-) output-4.096v, final produce ± 4.096v voltage receives respectively X0 and the X1 end of the multinomial analog switch of MAX4051AESE in Fig. 5;

The high frequency control port of MSP430F2111 chip is connected with the ADDA end of the multinomial analog switch of MAX4051AESE in Fig. 5, the high frequency control port output look-at-me of MSP430F2111 chip, the multinomial analog switch of MAX4051AESE is according to the bipolar voltage of the different output of the frequency of look-at-me different frequency, and hold by Excitation Signal the positive input terminal that outputs to the OPA551FA power amplifier in Fig. 6, after power amplification, the positive and negative 4.096v driving voltage replacing of stable output is to the exciting electrode two ends of impedance type moisture sensor, when fluid is when flowing through in sensor, potential electrode two ends produce output voltage signal,

The positive-negative input end that above-mentioned voltage signal accesses respectively AD620AR-S08 instrument amplifier is converted to unipolarity voltage signal over the ground, and input to the Vin end of AD637BR chip, through effective value, process by Signal (out) the end output direct current effective value voltage signal relevant with water percentage to micro-control circuit.

In addition to the implementation, the present invention can also have other embodiments, and all employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection domain of requirement of the present invention.

Claims (2)

1. an impedance type moisture sensor detection method, is characterized in that, the method realizes by the exciting electrode two ends access driving voltage at impedance type moisture sensor, comprises following concrete steps:

Step (1): 5V analog voltage y is provided ₀, by 5V analog voltage y ₀carry out voltage stabilizing processing and obtain reference voltage y ₁, and y ₁=4.096v;

Step (2): by the y in step (1) ₁according to following formula, be converted to the double-channel output signal of strict symmetry:

$\left\{\begin{array}{c}{y}_2=-y_1\&times;R_3/R_4\\ y_3=y_1\&times;R_3/R_4\end{array}\right.$

Wherein, y ₂be defined as the negative voltage signal of strict symmetry, y ₃be defined as the positive voltage signal of strict symmetry, R ₃be defined as the first gain resistor, R ₄be defined as the second gain resistor;

Step (3): by the y obtaining in step (2) ₂and y ₃according to following formula, be converted into the adjustable symmetric double polar voltages signal y of frequency ₄,

y ₄=(1-k)×y ₃+k×y ₂

Wherein, the height that k is defined as high frequency output replaces level, k=0 or 1; And k=0 time lasting with k=1 is identical;

Step (4): by the adjustable symmetric double polar voltages signal y of the frequency obtaining in step (3) ₄according to following formula, carry out obtaining high power AC voltage signal y after power amplification ₅:

Y ₅=(1-k) * y ₃+ k * y ₂, y ₅peak power be:

P=200mA×|y ₅|=200mA×4.096×R ₃/R ₄=0.8192×R ₃/R ₄；

Step (5): by the high power AC voltage signal y in step (4) ₅according to following formula, be converted to ac-excited voltage signal y ₆:

y ₆=[(1-k)×y ₃+k×y ₂]×k ₁

Wherein, k ₁be defined as electric discharge output level, and k ₁=0 or 1, k ₁within=0 o'clock, be discharge condition, k ₁=0 and k ₁=1 alternately occurs, k ₁each lasting time of=0 state is identical, k ₁each lasting time of=1 state is also identical, k ₁=1 each lasting time was compared k ₁=0 each lasting time is long;

Step (6): by the ac-excited voltage signal y obtaining in step (5) ₆the exciting electrode two ends of termination formula moisture sensor, when fluid flows through and k in sensor ₁=1 o'clock, potential electrode two ends output AC voltage signal y ₇, y ₇expression formula be:

y ₇=w×y ₆=w×[(1-k)×y ₃+k×y ₂]

Wherein, w is defined as water percentage and characterizes coefficient;

Step (7): by the ac voltage signal y obtaining in step (6) ₇be converted to direct current signal y ₈, measure y ₈and calculate water percentage sign coefficient w by following formula batch total:

$\left\{\begin{array}{c}{y}_8=w\&times;(y_3+|y_2\left|\right)/2\\ w=2\&times;y_8/(y_3+|y_2\left|\right)\end{array}\right..$

2. an impedance type moisture sensor pick-up unit, it is characterized in that, comprise that reference circuit, symmetric double polar voltages produce circuit, high-frequency AC excitation signal produces circuit, power amplification circuit, discharge circuit, true rms circuit and micro-control circuit, wherein:

Described reference circuit is used for 5V analog voltage y ₀carry out voltage stabilizing processing and obtain reference voltage y ₁;

Described symmetric double polar voltages produce circuit under the control of micro-control circuit by y ₁be transformed into the double-channel output signal y of strict symmetry ₂and y ₃, wherein, y ₂be defined as the negative voltage signal of strict symmetry, y ₃be defined as the positive voltage signal of strict symmetry;

Described high-frequency AC excitation signal produce circuit under the control of micro-control circuit by y ₂and y ₃be converted to the adjustable symmetric double polar voltages signal y of frequency ₄;

Described power amplification circuit is by the adjustable symmetric double polar voltages signal y of frequency ₄carry out obtaining high power AC voltage signal y after power amplification ₅, and be converted to ac-excited voltage signal y through discharge circuit ₆, ac-excited voltage signal y ₆the exciting electrode two ends of termination formula moisture sensor;

When fluid is when flowing through in sensor, the potential electrode two ends output AC voltage signal y of impedance type moisture sensor ₇, y ₇after true rms circuit, be converted to water percentage characterize coefficient w relevant be converted to direct current signal y ₈;

Micro-control circuit receives direct current signal y ₈, and record water percentage sign coefficient w.

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