CN1752722A - Dynamic transmission type capacity verification system and calibration method - Google Patents

Abstract

A kind of dynamic transmission type capacity verification system comprises the liquid conducting pipes (1) that links to each other with tested container; Especially be serially connected with standard pipe prover (2) and flowmeter (3) in the described liquid conducting pipes (1).A kind of dynamic transmission type capacity calibration method, especially this method may further comprise the steps: C, flowmeter measure relative steady section flow; When the volume pipe inner carrier triggered the downstream optoelectronic switch, computing machine began the flowmeter step-by-step counting; The volume pipe inner carrier continues to go downwards to lower dead center, and rests on this position; This step comprises: C1, designated water level limit M; C2, detect current water level, if reach water level limit M, then execution in step D; C3, flowmeter (3) metered flow also send metrical pulse to calibrating control device (41); Carry out C2 step by step.The present invention saves a large amount of repeater worker's operations by the calibrating liquid filling measurement means of robotization, can effectively improve calibrating efficient, reduces working strength greatly, shortens the calibrating time, guarantees the calibrating accuracy.

Description

Dynamic transmission type capacity verification system and calibration method

Technical field

The present invention relates to flow metering calibrating technology and instrument and meter system, particularly in the metering process, the high-precision measuring instrument is on-the-spot to transmit or proofreaies and correct the verification system and the method for measuring the result to inferior one-level gauging instrument in real time.

Background technology

Boats and ships liquid goods metering cabin, truck tank, oil tank etc. are one of main measurement instruments of oil and chemical products trade settlement, to the accurately calibrating fast of its capacity, are directly connected to trade transaction both sides' the economic interests and the just and reputation of metering arbitration.Along with going deep into of China marketization, also more and more higher to the requirement of metering, this at first is reflected in the increase of (need measure) amount, and the increase of amount just must need traditional calibration method is improved, to reach the purpose of quick calibrating and metering.Certainly, the basic demand of metering is accurate.

The main method that the said vesse calibrating is adopted at present has two kinds, geometric measurement method and capacity relative method.Geometric measurement method adopts survey instruments such as steel ruler and laser transit to directly measuring inside and outside the container exactly, calculates loading table according to its shapometer then.Volume ratio is to be medium with other suitable liquid of water than rule, the calibration method that compares with standard measuring device and tested measuring device.Geometric measurement method is fit to the calibrating to the regular shape measuring device, and volume ratio is than the calibrating of suitable non-regular measuring device of rule and middle low capacity measuring device.

In the calibrating of reality, greatly container is non-regular shape, perhaps owing to container becomes non-regular shape at the various annexes that are difficult to dimensional measurement.From the accuracy requirement of calibrating, non-regular shape measuring device need adopt the capacity relative method to examine and determine.

In the prior art, the capacity relative method is a kind of direct calibration method.The operating process of this method is, to examine and determine earlier with liquid filling to standard measuring device, read then and the record standard measuring device in fluid temperature, the wall temperature of standard measuring device, the liquid capacity value in the standard measuring device, afterwards the liquid in the standard measuring device is entered in the tested measuring device, after treating that liquid in the standard measuring device drains, carry out identical next time filling discharge process again.After the discharge process of once or several times annotating, and then measure and write down the wall temperature of the fluid temperature in the tested measuring device, tested measuring device, the data such as liquid height in the tested measuring device, so circulation finishes until calibrating.These processes can only be finished manually.

As can be seen, adopting the capacity relative method to carry out the container calibrating is a very heavy and careful job.As a medium-sized tanker oceangoing ship is examined and determine, generally need the some months time just can finish, the data volume of generation is about 10,000.

Obviously, the capacity relative method of container calibrating has the following disadvantages: the calibrating time is long, working strength is big; Generally at outdoor work, the variation of calibrating environment influences the accuracy of calibrating easily in the long calibration interval; There are a large amount of repetitive processes, occur mistake easily.Therefore, prior art can't solve within a short period of time, finish the calibrating of capacity with less working strength, can't in outdoor abominable changeable calibrating environment, guarantee the accuracy that container capacity is identified, also can't in artificial a large amount of repeated operation processes, avoid mistake.

Summary of the invention

The present invention is that the craft that overcomes the existence of prior art capacity relative method repeats the various drawbacks that work brings, a kind of dynamic transmission technology of capacity calibrating is proposed, calibrating liquid filling measurement means by robotization, save a large amount of repeater worker's operations, can effectively improve calibrating efficient, reduce working strength greatly, shorten the calibrating time, guarantee the calibrating accuracy.

The technical problem to be solved in the present invention is that at outdoor work, the variation of calibrating environment is to the influence of calibrating accuracy in the long calibration interval;

The technical solution used in the present invention is:

Propose a kind of dynamic transmission type capacity verification system, comprise the liquid conducting pipes that links to each other with tested container; Especially be serially connected with standard pipe prover and flowmeter in the described liquid conducting pipes.

The technical matters that the present invention further will solve is to have mistake unavoidably in artificial a large amount of repeatable operation processes.

The further technical scheme of taking of the present invention is:

Propose a kind of dynamic transmission type capacity verification system, also comprise the processing and control element (PCE) that links to each other with flowmeter with described volume pipe; Described volume pipe is the piston type volume pipe.

The technical matters that the present invention will solve on step is that in very long relatively metering process, the accuracy meeting of flowmeter changes or drift, thereby influences the accuracy of whole qualification result.

The technical scheme that the present invention is taked on step is:

A kind of dynamic transmission type capacity calibration method, especially this method may further comprise the steps:

C, flowmeter measure relative steady section flow;

When the volume pipe inner carrier triggered the downstream optoelectronic switch, computing machine began the flowmeter step-by-step counting; The volume pipe inner carrier continues to go downwards to lower dead center, and rests on this position; This step comprises step by step following:

C1, designated water level limit M;

C2, detect current water level, if reach water level limit M, then execution in step D;

C3, flowmeter 3 metered flows also send metrical pulses to calibrating control device 41; Carry out C2 step by step.

Adopt behind the present invention obtainable beneficial effect be: compare with traditional container calibrating means, adopt dynamic transmission technology can improve tens of times of work efficiency; The automaticity height greatly reduces labor intensity of operating personnel; The calibrating Time Compression to traditional calibration method required time 1/10th in; Only need artificial data record seldom, reduced or eliminated mistake.

Description of drawings

Fig. 1 is the k-factor figure of flowmeter;

Fig. 2 is the k-factor figure of flow range flowmeter when big;

Fig. 3 is the k-factor figure of hour flowmeter of flow range;

Fig. 4 is the k-factor figure of the flow range of flowmeter flowmeter when infinitely small;

Fig. 5 is that dynamically transmission type of the present invention capacity verification system realizes schematic diagram;

Fig. 6 is that boats and ships volume of compartment verification system is implemented illustration;

Fig. 7 is that rail tank car capacity verification system is implemented illustration.

EmbodimentBelow in conjunction with accompanying drawing in detail embodiments of the invention are described in detail.

A kind of dynamic transmission type capacity verification system comprises the liquid conducting pipes 1 that links to each other with tested container; Especially be serially connected with standard pipe prover 2 and flowmeter 3 in the described liquid conducting pipes 1.

Described dynamic transmission type capacity verification system also comprises the processing and control element (PCE) 4 that links to each other with flowmeter 3 with described volume pipe 2;

Described volume pipe 2 can be the piston type volume pipe.

Described dynamic transmission type capacity verification system also comprises the electrically operated valve 5 that is serially connected with on the conveyance conduit 1 and the filtrator 6 of cooling down.Before the described filtrator 6 of cooling down is connected on volume pipe.

Described processing and control element (PCE) 4 comprises calibrating control device 41 and the two-way data processing equipment that is connected 42 with it.

A kind of dynamic transmission type capacity calibration method, this method may further comprise the steps:

C, flowmeter measure relative steady section flow;

When the volume pipe inner carrier triggered the downstream optoelectronic switch, computing machine began the flowmeter step-by-step counting; The volume pipe inner carrier continues to go downwards to lower dead center, and rests on this position; This step comprises step by step following:

C1, designated water level limit M;

C2, detect current water level, if reach water level limit M, then execution in step D;

C3, flowmeter 3 metered flows also send metrical pulses to calibrating control device 41; Carry out C2 step by step.

This calibration method is further comprising the steps of:

A, metered volume pipe are prepared before driving valve;

The volume pipe piston is risen to top dead centre, and break off relations with chain.Lift valve cuts out, and piston is static rests on a certain position before the optoelectronic switch of upstream, and the grating chi detects this position as the piston reference position and note, and sends valve opening signal;

B, metered volume pipe are driven valve and are measured the ascent stage flow;

The fluid injection variable valve is opened, descent of piston, and variable valve is opened the flow velocity that finishes and is risen to maximum, and piston continues descending, triggers the downstream optoelectronic switch.COMPUTER CALCULATION is opened valve section volume, i.e. volume between piston reference position and the downstream optoelectronic switch;

D, metered volume pipe close valve to be prepared;

This moment, volume pipe started hoisting gear.Piston is raised up, arrives after top dead center and chain and breaks off relations; The unhook back piston begins to trigger the upstream optoelectronic switch toward the downstream motion, and provides pass valve order, and computing machine stops the counting to the flowmeter pulse simultaneously;

E, metered volume pipe close valve and measure the descending branch flow;

Variable valve receives and closes the valve order, begins to close valve, and piston continues descending in pass valve process; Close valve and carry out in two stages, the phase one, the variable valve action is closed to the small aperture place that sets, and flow is diminished, and piston is slowly descending; Subordinate phase, this water injection rate of computer monitoring; When water injection rate arrives predetermined value, close variable valve fully; The pass valve finishes, and piston stops descending, and terminates in a certain position; The grating chi detects the final position of piston, and closes valve section volume, i.e. volume between upstream optoelectronic switch and the piston final position by COMPUTER CALCULATION;

F, data processing equipment calculate total volume;

Total volume=open valve section capacity+steady section flow+pass valve section capacity.

In the practicality, the principle of the dynamic transmission technology of capacity calibrating is as follows:

The accuracy problems of flowmeter.Suppose at flow range Qmin in Qmax, the curve of the coefficient of flow k of flowmeter as shown in Figure 1, then at Qmin in the flow range of Qmax, the performance index of flowmeter can be represented by the formula:

The linearity E of flowmeter _L:

$E_L=\±\frac{k_{i\max }-k_{i\min }}{k_{i\max }+k_{i\min }}\×100\%------\left(1\right)$

In the formula: k _Imax-----Q _MinTo Q _MaxFlow range in maximal value in each flow point k-factor

k _Imin------Q _MinTo Q _MaxFlow range in minimum value in each flow point k-factor

Wherein relate to three parameters:

The one, the fundamental error δ of flowmeter:

$\mathrm{\δ}=\±\sqrt{{\mathrm{\&Egr;}}_s^2+{\mathrm{\&Egr;}}_L^2}\×100\%---\left(2\right)$

In the formula: E _sBe used to examine and determine the error of the flow standard of flowmeter

According to the meter proof rules, if the error E of flow standard _sDo not exceed 1/3 o'clock of tested flowmeter limit of intrinsic error, can ignore E _s.In the application of reality, the error of flow standard can both satisfy 1/3 the requirement that does not exceed tested flowmeter limit of intrinsic error, and claim the linearity of flowmeter to be equal to fundamental error this moment.

The 2nd, the repeated E of flowmeter _r:

$E_r=\max [\frac{1}{k_i}\sqrt{\frac{1}{n-1}\underset{J=1}{\overset{n}{\mathrm{\Σ}}}{(k_{\mathrm{ij}}-k_i)}^2}\×100\%]---\left(3\right)$

In the formula: n is the calibrating number of times of i flow point

k _IjIt is the coefficient of flow of the j time demarcation of i flow point

k _iBe i the coefficient of flow that flow point is average

The 3rd, the accuracy E of flowmeter:

$E=\max (\mathrm{\δ},{3E}_r)---\left(4\right)$

The flow accuracy confirmed by the fundamental error (generally being equal to the linearity) and the repeatability of flowmeter, is specially the fundamental error of getting flowmeter and the greater of 3 times of flowmeter repeatability indexs.

Improve the flowmeter accuracy.According to the accuracy definition of flowmeter, be by its linearity and the common decision of repeatability.And the repeatability of flowmeter is its intrinsic propesties, generally is a fixing value.If we select for use or at the very high flowmeter of a kind of repeatability index, as turbo flow meter or blade flowmeter, in this case, the accuracy that the method for the linearity that can be by improving flowmeter improves flowmeter.

Fig. 2 and Fig. 3 have demonstrated the approach that improves the linearity of flowmeter.

Contrast two figure as can be seen, when flow range reduces, flowmeter k-factor (k _Imax-k _Imin) also corresponding reducing, thereby by formula

The linearity index that calculates also reduces, and has promptly improved the linearity.

Dynamic TRANSFER METHOD of the present invention can improve the accuracy of flowmeter by reducing flow range.If the flow range of flowmeter is dropped to infinitesimal, when promptly becoming a flow point, the linearity of flowmeter just equals zero, as shown in Figure 4.At this moment, by formula

The fundamental error δ of the flowmeter that calculates is:

$\mathrm{\δ}=\±\sqrt{E_s^2+E_L^2}\×100\%=\±\left|E_s\right|\×100\%$

In the formula, Es is the error that is used to examine and determine the flow standard of flowmeter.

The following formula explanation, if we cooperate with accurate flow standard with a very high flowmeter of repeatability index, flow standard carries out on-line proving to flowmeter in real time, can think that so the working flow scope of flowmeter is 0, therefore its linearity EL equals 0, its fundamental error is exactly the fundamental error of flow standard, and the method for accuracy of this raising flowmeter is called dynamic TRANSFER METHOD.

Following formula illustrates that also dynamically TRANSFER METHOD passes to flowmeter with the high precision of flow standard in fact exactly.

Dynamically the realization of transmission type capacity verification system as shown in Figure 5.The flow measuring system that adopts dynamic transmission technology to form is made up of four parts, and wherein most critical is flow standard and flowmeter, and these several parts are respectively:

Flow standard partly adopts the piston type standard pipe prover, and its repeatability is E _Sr=0.02%.

The flowmeter part is the repeatability index height to the requirement of flowmeter, generally can use turbo flow meter, blade flowmeter etc.

The processing controls part is made up of control module, computer and software.It is responsible for control, operating and setting, data processing of system etc.

Fluid treatment and flow control part 8 comprise the liquid source, the filtrator of cooling down, electric control valve, power supply unit etc.

Adopt of the calibrating of dynamic transmission technology, according to deciding liquid level and quantitative manner work to capacity.The calibrating mode can have manually and semi-automatic two kinds.The liquid measure that enters tested measuring device is measured by flowmeter, and the flowmeter in the metering system is among metering and the circulation out of service under the control of by-pass valve control, and its condition out of service is the liquid measure that reaches regulation liquid level or regulation.After the collection of finishing relevant data and input, flowmeter enters next metering process again, so goes round and begins again and finishes until a tested measuring device calibrating.

In the metering process of a flowmeter, the calibrating medium enters the tested measuring device that needs calibrating through cool down filtrator 6, volume pipe 2, flowmeter 3, by-pass valve control 5 etc.According to the time interval and the mode of program setting, standard pipe prover 2 is regularly demarcated flowmeter 3, demarcates the coefficient of flow that all draws this flowmeter current working each time.This coefficient of flow is applied to the flow rate calculation of flowmeter current generation in real time.

After calibrating finished, the various data that the calibrating Control Software will gather and import were handled according to the requirement of rules, printed height loading table, calibration certificate etc. then.Compare with traditional mode of utilizing standard measuring device to examine and determine, this method can improve tens of times of work efficiency.

Dynamically in the TRANSFER METHOD, relate to the uncertainty of measurement of flowmeter, its component has following several:

The measurement type A standard uncertainty u1 of flowmeter, ${\mathrm{<figure-callout\; id="1"\; label="u"\; filenames="A20041005158200102.png,A20041005158200111.png"\; state="\{\{state\}\}">u</figure-callout>}}_1=\frac{1}{k}\sqrt{\frac{1}{n-1}}\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{(k_j-k)}^2\&times;100\%$

Wherein, n dynamically transmits the calibrating number of times of real-time traffic point down-off standard to flowmeter

k _jFor dynamically transmitting the coefficient of flow of real-time traffic point down-off standard to the j time calibrating of flowmeter $k=\frac{\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{k}_j}{n}$ It is the k-factor of current flux point.

u ₁In fact be exactly the repeatability of flowmeter.

The flow measurement uncertainty u that flowmeter causes when not examining and determine together with matching instrument ₂, dynamically TRANSFER METHOD is demarcated matching instrument is examined and determine together, so u ₂=0.

The flow measurement uncertainty u that the fluid condition of meter proof and use does not cause simultaneously ₃, because dynamically TRANSFER METHOD is the real liquid calibrating of a kind of online in real time, so u ₃=0.

The data acquisition and processing (DAP) uncertainty causes flow measurement uncertainty u ₄With the synthetic uncertainty u of flow standard ₅

As seen, the combined standard uncertainty u of the combined standard uncertainty flowmeter of flowmeter is

$u=\sqrt{{\mathrm{<figure-callout\; id="1"\; label="u"\; filenames="A20041005158200102.png,A20041005158200111.png"\; state="\{\{state\}\}">u</figure-callout>}}_1^2+u_2^2+u_3^2+{\mathrm{<figure-callout\; id="4"\; label="u"\; filenames="A20041005158200121.png"\; state="\{\{state\}\}">u</figure-callout>}}_4^2+u_5^2}$

Because u ₂=0, u ₃=0, then $u=\sqrt{{\mathrm{<figure-callout\; id="1"\; label="u"\; filenames="A20041005158200102.png,A20041005158200111.png"\; state="\{\{state\}\}">u</figure-callout>}}_1^2+{\mathrm{<figure-callout\; id="4"\; label="u"\; filenames="A20041005158200121.png"\; state="\{\{state\}\}">u</figure-callout>}}_4^2+u_{5.}^2}$

Therefore, the expanded uncertainty U of flowmeter is U=ku,

Confidence level by 95% is got k=2, then

$U=2\sqrt{{\mathrm{<figure-callout\; id="1"\; label="u"\; filenames="A20041005158200102.png,A20041005158200111.png"\; state="\{\{state\}\}">u</figure-callout>}}_1^2+{\mathrm{<figure-callout\; id="4"\; label="u"\; filenames="A20041005158200121.png"\; state="\{\{state\}\}">u</figure-callout>}}_4^2+u_5^2}$

Below be boats and ships volume of compartment verification system embodiment.

Boats and ships capacity verification system figure sees Fig. 6.System partly is made up of liquid source, flow metering, calibrating control and distribution etc.

Liquid source part mainly comprises self-priming centrifugal pump, the filtrator of cooling down, pressure-regulating valve, pipeline and annex etc.

Self-priming centrifugal pump is used for the extraction of water, for metering system is supplied with the calibrating medium.The effect of filtrator of cooling down is the gassiness that guarantees to supply water, contains assorted the satisfy service requirement of volume pipe and flowmeter and the requirement of container calibrating.Pressure-regulating valve is responsible for the pressure controlled execution of total system, and when the flowrate control valve of system outlet cut out, pressure-regulating valve generally was in larger opening, to guarantee the stable of pressure and normally beginning of metering process next time.

The flow metering part is made up of piston type standard pipe prover, high repeatable accuracy blade flowmeter, electric control valve etc.

Blade flowmeter is the capacity measurement working stamndard of cabin volume calibration, certain (water volume) amount is all represented in each pulse of its output, therefore, as long as the flowmeter umber of pulse that switching device shifter is led during the cabin is accumulated, just can calculate the water yield that enters cabin.The amount of each pulse representative of blade flowmeter output is called the pulse equivalency coefficient, or is the k-factor of flowmeter, and its value is determined the calibrating of blade flowmeter by standard pipe prover.

Because in the k-factor affirmation process of flowmeter, volume pipe and flowmeter are in same operating mode, i.e. same media, uniform temp and pressure, same traffic, therefore, volume pipe can pass to blade flowmeter with its pin-point accuracy.

The calibrating control section is made up of calibrating control module, computer and software.It is responsible for control, operating and setting, data processing of system etc.

Power supply unit also is the operation and the protected location of water pump to the power supply of each several part consumer simultaneously.In the system, except that water pump was the 380Vac power supply, the voltage supplied of other instrument and equipment was 220Vac or direct current.

For the flow error that produces in the process of eliminating the variable valve opening and closing, native system adopts volume pipe that the process of regulating opening of valves and close is done synchronous measurement, and committed step of the present invention is as follows:

Prepare before driving valve.The volume pipe piston is risen to top dead centre, and break off relations with chain.Lift valve cuts out, and piston is static rests on a certain position before the optoelectronic switch of upstream, and the grating chi detects this position as the piston reference position and note, and sends valve opening signal;

Open the valve process.The fluid injection variable valve is opened, descent of piston, and variable valve is opened the flow velocity that finishes and is risen to maximum, and piston continues descending, triggers the downstream optoelectronic switch.COMPUTER CALCULATION is opened valve section volume (volume between piston reference position and the downstream optoelectronic switch).

The flowmeter counting.When triggering the downstream optoelectronic switch, computing machine begins the flowmeter step-by-step counting.The volume pipe inner carrier continues to go downwards to lower dead center, and rests on this position, waits for closing the preceding warning order of valve.

Prepare before closing valve.When the flowmeter counting arrives intentional lead, enter and close the preceding preparation of valve.This moment, volume pipe started hoisting gear.Piston is raised up, arrives after top dead center and chain and breaks off relations.The unhook back piston begins to trigger the upstream optoelectronic switch toward the downstream motion, and provides pass valve order, and computing machine stops the counting to the flowmeter pulse simultaneously.

Close valve.Variable valve receives and closes the valve order, begins to close valve.Piston continues descending in pass valve process.Closing valve carries out in two stages.Phase one, the variable valve action is closed to the small aperture place that sets, and flow is diminished, and piston is slowly descending.Subordinate phase, this water injection rate of computer monitoring.When water injection rate arrives predetermined value, close variable valve fully.The pass valve finishes, and piston stops descending, and terminates on a certain position.The grating chi detects the final position of piston, and closes valve section volume (volume between upstream optoelectronic switch and the piston final position) by COMPUTER CALCULATION.

The water filling volume calculations.Water filling volume=open valve section volume+flowmeter cumulative volume+pass valve section volume

Rail tank car capacity verification system embodiment sees Fig. 7.The composition of system and key operation step are basic identical, but at be the calibrating of rail tank car.

Claims (6)

1, a kind of dynamic transmission type capacity verification system comprises the liquid conducting pipes (1) that links to each other with tested container; It is characterized in that:

Be serially connected with standard pipe prover (2) and flowmeter (3) in the described liquid conducting pipes (1).

2, verification system according to claim 1 is characterized in that:

Also comprise the processing and control element (PCE) (4) that links to each other with flowmeter (3) with described volume pipe (2);

Described volume pipe (2) is the piston type volume pipe.

3, verification system according to claim 2 is characterized in that:

Also comprise electrically operated valve (5) that is serially connected with on the conveyance conduit (1) and the filtrator of cooling down (6).

4, according to claim 2 or 3 described verification systems, it is characterized in that:

Described processing and control element (PCE) (4) comprises calibrating control device (41) and the two-way data processing equipment that is connected (42) with it.

5, a kind of dynamic transmission type capacity calibration method is characterized in that this method may further comprise the steps:

C, flowmeter measure relative steady section flow;

When the volume pipe inner carrier triggered the downstream optoelectronic switch, computing machine began the flowmeter step-by-step counting; The volume pipe inner carrier continues to go downwards to lower dead center, and rests on this position; This step comprises step by step following:

C1, designated water level limit M;

C2, detect current water level, if reach water level limit M, then execution in step D;

C3, flowmeter (3) metered flow also send metrical pulse to calibrating control device (41); Carry out C2 step by step.

6, calibration method according to claim 5 is characterized in that:

This method is further comprising the steps of:

A, metered volume pipe are prepared before driving valve;

The volume pipe piston is risen to top dead centre, and break off relations with chain.Lift valve cuts out, and piston is static rests on a certain position before the optoelectronic switch of upstream, and the grating chi detects this position as the piston reference position and note, and sends valve opening signal;

B, metered volume pipe are driven valve and are measured the ascent stage flow;

The fluid injection variable valve is opened, descent of piston, and variable valve is opened the flow velocity that finishes and is risen to maximum, and piston continues descending, triggers the downstream optoelectronic switch.COMPUTER CALCULATION is opened valve section volume, i.e. volume between piston reference position and the downstream optoelectronic switch;

D, metered volume pipe close valve to be prepared;

This moment, volume pipe started hoisting gear.Piston is raised up, arrives after top dead center and chain and breaks off relations; The unhook back piston begins to trigger the upstream optoelectronic switch toward the downstream motion, and provides pass valve order, and computing machine stops the counting to the flowmeter pulse simultaneously;

E, metered volume pipe close valve and measure the descending branch flow;

Variable valve receives and closes the valve order, begins to close valve, and piston continues descending in pass valve process; Close valve and carry out in two stages, the phase one, the variable valve action is closed to the small aperture place that sets, and flow is diminished, and piston is slowly descending; Subordinate phase, this water injection rate of computer monitoring; When water injection rate arrives predetermined value, close variable valve fully; The pass valve finishes, and piston stops descending, and terminates in a certain position; The grating chi detects the final position of piston, and closes valve section volume, i.e. volume between upstream optoelectronic switch and the piston final position by COMPUTER CALCULATION;

F, data processing equipment calculate total volume;

Total volume=open valve section capacity+steady section flow+pass valve section capacity.

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