JP4663041B2 - Flow measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flow rate measuring device that measures the flow rate of a fluid such as a gas.
[0002]
[Prior art]
Many methods are known for measuring the flow rate and flow rate of fluids such as gas and liquid, but the development of flow rate and flow rate measurement devices that use highly reliable ultrasonic waves is particularly remarkable due to advances in electronics technology. . Ultrasonic flow velocity / flow rate measuring devices have a wide range of application fields such as fuel gas meters, industrial measuring instruments, medical blood flow meters, and measurement of flow rates in the ocean and the atmosphere. The flow velocity / flow rate measuring device using ultrasonic waves is not only used directly for ultrasonic waves but also indirectly used as a detection unit of a measuring device based on many measurement principles.
[0003]
Moreover, many sensors such as a flow rate sensor, a resistance value sensor, a temperature sensor, and a voltage sensor are used for the flow rate / flow rate measurement device as well as the ultrasonic flow rate / flow rate measurement device. And the sensor which transmits these electric signals may be influenced by external conditions and a sensitivity may change. For this reason, a flow measuring device used for a fuel gas meter or the like is required to measure even a slight change in flow rate, for example, a minute change such as 3 liters / hour, and such a minute change can be accurately grasped. In order to be able to do this, the measurement device must be capable of correcting the zero point of the measurement.
[0004]
From the above viewpoint, the technique disclosed in Japanese Patent Laid-Open No. 8-271307 determines whether it is appropriate to perform zero point correction at predetermined time intervals, and executes zero point correction based on the determination. It is a gas flow meter equipped with means, and is highly evaluated in the gas appliance industry as a useful technique.
[0005]
[Problems to be solved by the invention]
However, the gas flow meter described above determines whether or not zero point correction needs to be performed at a predetermined time interval, and performs zero point correction when necessary. Since the flow path cannot be closed indefinitely in a device in which the flow is not traced, zero point correction cannot be performed.
[0006]
Therefore, in view of the problems of the conventional example, the present invention has a structure having a plurality of flow paths, and corrects the zero point of the flow path where the fluid flow rate is not measured, thereby allowing the flow path for fluid measurement. It is an object of the present invention to use a flow path that has been subjected to zero point correction.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a plurality of flow paths provided between an inlet and an outlet, a plurality of open / close means for individually opening and closing the plurality of flow paths, and a flow rate of at least one flow path. Measuring means for measuring, and control means for controlling the opening / closing means and the measuring means, wherein the control means detects a zero value of the measuring means in a flow path in which the opening / closing means is closed to detect a zero value. This is a flow rate measuring device provided with a zero point verification means for performing correction.
[0008]
According to the present invention, with a configuration having a plurality of flow paths, the measurement range of the fluid flow rate is enlarged, and even in a device where the flow rate is not traced, the zero point of the flow path where the fluid flow rate is not measured is set. By correcting and switching the opening / closing means, it becomes possible to perform fluid measurement in the flow path where the zero point correction has been completed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is extremely useful when applied to a fuel gas meter such as city gas and propane gas. This is because it is required in Japan that the fuel gas meter accurately grasps the flow rate change exceeding 3 liters per hour. Therefore, the present invention is convenient in that the flow rate can be accurately measured by the zero point correction over a wide range such as tens of thousands of liters per hour since the change in the flow rate is extremely small. The present invention is useful when implemented in various fields where it is necessary to measure an accurate flow rate in accordance with the above-described purpose.
[0010]
Those skilled in the art can implement the present invention by adopting the configuration described in each claim, but the embodiments can be easily grasped by helping understanding of the contents of the present invention. In addition to the means and configuration, the effects of the claims will be described below.
[0021]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0022]
Example 1
FIG. 1A is a block diagram showing the configuration of a flow rate measuring apparatus according to the first embodiment according to claim 1 and claim 2, FIG. 1B is a schematic diagram of the flow rate detecting means, and FIG. 2 is a block diagram of the measuring means. .
[0023]
In the figure, 1 is an inflow path, 2 is an outflow path, 3 is a flow path, 4 is an opening / closing means for opening and closing the flow path, 5 is a measuring means for measuring the flow rate of the flow path, 7 is the opening / closing means 4 and the measuring means 5. It is a control means to control. A zero point test means 6 is provided inside the control means.
[0024]
Next, the operation and action will be described. In FIG. 1, the flow path 3 is composed of three lines, and an opening / closing means 4 and a measuring means 5 are attached to each flow path. The fluid entering from the inflow path 1 passes through the open / close means 4 and the flow rate is measured by the measuring means 5. The opening / closing means 4 and the measuring means 5 are controlled by the control means 7. The opening / closing means 4 can be opened and closed with respect to each flow path. Then, the flow rate measuring means 5 in which the opened opening / closing means 4 is present measures the flow rate. The total flow rate from the inflow path 1 to the outflow path 2 is obtained by adding the flow rates of the individual measuring means 5 by the control means 7.
[0025]
When all of the plurality of flow paths are opened, it is possible to flow a large flow rate and to measure it. If only one flow path is opened, a small flow rate can be handled. By using the opening / closing means 4 as described above, it is possible to easily select a flow path according to the flow rate and to perform measurement in a wide range of the flow rate region.
[0026]
The flow path 3 may be combined with a plurality of channels having an equal cross-sectional area to increase versatility and facilitate maintenance, and the cross-sectional area may be made different so that the optimum flow path is selected depending on the flow rate. It is good also as a structure to perform. In the present invention, the number of flow paths is three, but it is not necessarily meaningful to take numbers separately. Any number of two or more may be used.
[0027]
On the other hand, as the operation of the flow rate calculation means 20 composed of a plurality of flow paths, the flow rate of the fluid flow path 3 that flows through the whole is also calculated by the operation of the measurement means 5 performed in each flow path described above. The total flow rate obtained here is Q, and the flow rates obtained and calculated by the flow rate detection means 5a, 5b, 5c installed in the flow paths 3a, 3b, 3c opened by the opening / closing means 4 are qa, qb, qc, respectively. Then, Q is qa + qb + qc = Σq.
[0028]
If the opening / closing means 4a is closed while performing this flow rate calculation, no fluid flows through the flow path 3a. Therefore, when the fluid flow rate is measured by the measuring means 5a, the flow rate should be 0 because the opening / closing means 4a is closed. However, the zero point of the measuring means 5a may be shifted due to external influences such as temperature or aging, and the measured value is corrected by the zero point verification means 6 based on the value of the flow rate calculating means 20. To do. The correction is established by setting the value measured by the measuring means 5a as a basic value and then increasing / decreasing the value measured by the measuring means 5a when the opening / closing means 4a is opened next time. This zero point test can be performed by the measuring means 5 installed in the flow path 3 having the closed opening / closing means 4.
[0029]
At this time, when the zero point is greatly deviated, it is also effective to notify the user of the abnormality using a notification means or the like. In addition, if an external administrator is notified using a communication means or the like, it is possible to quickly recover from an abnormal state, which is useful.
[0030]
The flow path 3 may be combined with a plurality of channels having an equal cross-sectional area to increase versatility and facilitate maintenance, and the cross-sectional area may be made different so that the optimum flow path is selected depending on the flow rate. It is good also as a structure to perform. In the present invention, the number of flow paths is three, but it is not necessarily meaningful to take numbers separately. Any number of two or more may be used.
[0031]
In addition, the flow rate detection means 1 in the flow path A indicated by the white arrow in FIG. 1 includes a first ultrasonic transducer 10 and a second ultrasonic transducer in a part of the fluid flow path 3 as shown in FIG. 11 is provided so as to be opposed to the direction of fluid flow. As shown in FIG. 2, 12 is a transmission circuit to the first vibrator 10, 13 is an amplification circuit for a signal received by the second vibrator 11, and the amplified signal is compared with a reference signal by a comparison circuit. When a signal equal to or higher than the reference signal is detected, the ultrasonic signal is repeatedly transmitted after the signal is delayed by the delay means by the repeat means for the set number of times. The time when the set number of ultrasonic transmissions is repeated and finished is obtained by the time measuring means 18 such as a timer counter.
[0032]
Next, transmission / reception of the first vibrator 10 and the second vibrator 11 is switched by the switching means 19, and ultrasonic waves are transmitted from the second vibrator 11 to the first vibrator 10, that is, from downstream to upstream. Repeat the time as described above. Then, the fluid velocity is calculated from the time difference, and the flow rate is calculated by the flow rate calculation means 20 inside the control means 7 from the cross-sectional area of the fluid flow path 3 and the fluid speed.
[0033]
As described above, the flow rate can be measured without disturbing the flow of the fluid by using the ultrasonic wave in the measuring means, and the flow rate can be measured instantaneously and accurately in a wide range by combining a plurality of flow paths.
[0034]
(Example 2)
Hereinafter, a flow rate measuring device according to a second embodiment of the present invention relating to claim 3 will be described with reference to the drawings.
[0035]
The block diagram showing the configuration of the present embodiment uses the same FIG. 1 as in the first embodiment. In addition, the same number is attached | subjected to the same component as Example 1, and detailed description is abbreviate | omitted. FIG. 3 shows a block diagram of the control means, and FIG. 4 shows an operation timing chart.
[0036]
The second embodiment is different from the first embodiment in that the first timer means 21 for managing the time in order to switch the opening / closing means at regular time intervals is provided.
[0037]
The operation will be described. As shown in FIG. 4 (a), the control means 7 opens the opening / closing means 4a and allows fluid to flow through the flow path 3a. When the opening / closing means 4a is opened, the first timer means 20 starts its operation as shown in FIG. 4 (d), and sends a signal to the control means 7 after a certain time (here, T1). In response to a signal from the first timer means 21, the control means 7 opens the opening / closing means 4b as shown in FIG. 4B, and then closes the opening / closing means 4a. At this time, the measuring means 5b is assumed to have corrected the zero point before opening the opening / closing means 4b. When T1 further elapses, the opening / closing means 4c is opened as shown in FIG. 4C, and then the opening / closing means 4b is closed. In this way, the flow path for measuring the fluid is replaced every time a certain time elapses.
[0038]
Thereby, even when there is a fluid flow and the flow rate is measured, the measuring means 5 of the flow path 3 in which the opening / closing means 4 is closed has already corrected the zero point by performing the zero point correction, and the measurement is performed. Even if there is a change in the zero point due to aging in the inner flow path, switching the flow path 3 via the opening / closing means 4 ensures good stability within a certain time interval and enables measurement without deviation of the zero point. It is possible to prevent the accuracy from becoming unstable.
[0039]
(Example 3)
Hereinafter, a flow rate measuring device according to a third embodiment of the present invention relating to claims 4 and 5 will be described with reference to the drawings.
[0040]
The block diagram showing the configuration of the present embodiment uses the same FIG. 1 as in the first embodiment. In addition, the same number is attached | subjected to the same component as Example 1, and detailed description is abbreviate | omitted. FIG. 5 shows a block diagram of the control means, and FIG. 6 shows an operation timing chart.
[0041]
In the third embodiment, when the measured fluid flow rate is smaller than the predetermined flow rate, the zero point verification unit 6 starts the verification. On the contrary, when the measured fluid flow rate is higher than the predetermined flow rate, the zero point verification unit 6 stops the verification. The point which is provided with the flow volume determination means 22 which sends out a signal differs from Example 1 and Example 2. FIG.
[0042]
The operation will be described. The control means 7 opens the opening / closing means 4a at time t1 in FIG. 6 to flow a fluid through the flow path 3a. Then, the flow rate of the fluid flowing in the flow rate calculation means 20 is obtained. Here, the flow rate determination means 22 sends a signal to the control means 7 when the flow rate obtained by the flow rate calculation means becomes smaller than a predetermined value (FIG. 6Q1) (time t2). The zero point of the measuring means 5b, 5c of the flow path having is corrected. This is because the possibility that the flow rate is reduced and the opening / closing means 4 is opened to allow the fluid to flow through the other flow path 3b and the flow rate to be measured using a plurality of flow paths is reduced.
[0043]
In addition, since the flow rate is small, even in the flow path 3 that closes the opening / closing means 4, the zero point can be verified when the flow of fluid is small and there is no error due to disturbance from the downstream. In the present embodiment, the zero point is verified as soon as the flow rate becomes less than Q1, but noise is superimposed on the flow rate signal or the flow rate itself fluctuates, so that a certain time has elapsed since the flow rate became Q1 or less. If the zero point test is performed later, the correction can be performed more stably.
[0044]
Further, the flow rate determination means 22 sends a signal to the control means 7 and closes when the flow rate obtained by the flow rate calculation means 20 exceeds a predetermined value (FIG. 6Q2) (time t3 in FIG. 6). The operation for correcting the zero point of the flow path measuring means 5b, 5c of 4c, etc. is stopped. This is because the flow rate is increased, so that disturbance due to a large flow rate enters from the downstream of the flow path 3 that closes the opening / closing means 4, and the zero point correction of the measuring means 5 that has been performed is affected, and the large flow rate is measured. This is because it is highly likely that the opening / closing means must be opened to allow fluid to flow through the flow path, so that the zero point verification is stopped and preparations for flow rate measurement are made immediately.
[0045]
Example 4
Hereinafter, the flow rate measuring device according to the fourth embodiment of the present invention will be described with reference to the drawings.
[0046]
The block diagram showing the configuration of the present embodiment uses the same FIG. 1 as in the first embodiment. In addition, the same number is attached | subjected to the same component as Example 1, and detailed description is abbreviate | omitted. FIG. 7 shows a block diagram of the control means, and FIG. 8 shows an operation timing chart.
[0047]
The fourth embodiment is provided with second timer means 23 for managing the time so as to correct the zero point of the measuring means of the flow path that is closed at regular intervals. Different from Example 3.
[0048]
Since the second timer means 23 is provided in the fourth embodiment, when the opening / closing means 4a is opened at time t1 in FIG. 8C and a fluid is flowing through the flow path 3a, the operation is started at time t1. The second timer means 23 sends a signal every time the predetermined time T2 elapses, and in response to this signal, the zero point verification means 6 in the control means 7 verifies the zero point of the measuring means 5b in the closed flow path 3b. . At this time, the measuring means 5c in the flow path 3c may be similarly tested. Similarly, when the opening / closing means 4a is closed at time t2 (FIG. 8 (a)) and the opening / closing means 4b is opened (FIG. 8 (b)), the second timer means 22 starts its operation from time t2 and starts at the interval T2. Send a signal with. In response to this signal, the zero point verification means 6 now verifies the zero point of the measurement means 5a in the flow path 3a.
[0049]
In this way, the measuring means 5 in the flow path 3 that is closing the opening / closing means 4 can be zero-corrected at a constant time interval T2, and a zero point shift occurs due to a change with time including disturbances such as temperature and humidity. Even within a certain period of time, it becomes possible to reduce the fluctuations, and even if the flow rate suddenly increases and the flow path must be opened and used, it can sufficiently cope with it. .
[0050]
(Example 5)
Hereinafter, the flow rate measuring device according to the fifth embodiment of the present invention relating to claims 7 and 8 will be described with reference to the drawings.
[0051]
The block diagram showing the configuration of the present embodiment uses the same FIG. 1 as in the first embodiment. In addition, the same number is attached | subjected to the same component as Example 1, and detailed description is abbreviate | omitted. FIG. 9 shows a block diagram of the control means.
[0052]
The fifth embodiment is different from the first, second, third, and fourth embodiments in that the control means includes a timing means and a storage means.
[0053]
Next, the operation will be described. The control means 7 opens the plurality of opening / closing means 4 and allows fluid to flow. At that time, the zero point of the measuring means 5 of the flow path having the closed opening / closing means 4 is corrected.
[0054]
Here, the control means 7 has a time measuring means 24, which sends a signal to the zero point test means at a predetermined time, and corrects the zero point of the measuring means 5 in the closed flow path 3. . As a result, the flow rate characteristic of the system in which the flow rate measuring device is installed is measured in advance, and the accuracy of the measuring means 5 can be adjusted to the optimal time by correcting the zero point at a time when the flow rate is low, for example. . In addition, the predetermined time may be set statistically, or if it is a gas flow rate method for home use, it can be set to a time except for morning, noon meals, evening to night baths, showers, This is the time during which the gas that is the fluid to be detected hardly flows. By setting the number of times and the time in advance, the zero point calibration error can be reduced and adjusted.
[0055]
Further, the control means 7 includes the time measuring means 24 and the storage means 25, so that the time when the stable flow rate Q continuously below a predetermined flow rate is continuously stored by the time measuring means 24 is stored in the storage means 25, and is closed. By performing the operation for correcting the zero point of the measuring means 5 in the flow path at the time stored in the storage means 25, the inherent use condition and state to which the system is attached are stored in advance, and stable. It is possible to adjust the measuring means 5 with higher accuracy by examining the zero point state of the measuring means 5 at the time of the state.
[0056]
For example, when used in a home gas flow meter, the morning, noon meal, bath use from evening to midnight, heating use time, etc. are not constant depending on the lifestyle of each home. By measuring the time when the flow rate becomes equal to or less than a predetermined value by the measuring unit 5 and learning while repeatedly storing it, the control unit 7 determines the time when the zero point of the measuring unit 5 is verified. Judge using If the calendar function is provided, the usage time of the gas may be greatly different between weekdays and weekends, and it can be assembled as a judgment material by the storage means.
[0057]
(Example 6)
Hereinafter, the flow rate measuring device according to the sixth embodiment of the present invention will be described with reference to the drawings.
[0058]
The block diagram showing the configuration of the present embodiment uses the same FIG. 1 as in the first embodiment. In addition, the same number is attached | subjected to the same component as Example 1, and detailed description is abbreviate | omitted. FIG. 10 shows a block diagram of the control means.
[0059]
The sixth embodiment is different from the first, second, third, fourth, and fifth embodiments in that the control unit includes a communication unit.
[0060]
In the sixth embodiment, the control unit 7 includes a communication unit 26. Usually, the control means 7 opens the plurality of opening / closing means 4 and allows fluid to flow. At that time, the zero point of the measuring means 5 of the flow path having the closed opening / closing means 4 is corrected. The timing for correcting the zero point may be automatically controlled using, for example, the timer means 23 in the control means 7, but the user or an external engine may want to perform a confirmation operation at an arbitrary time. At that time, the flow rate measuring device is configured to be able to communicate with the outside using the communication means 26 of FIG. The user instructs the start of the confirmation operation from the outside using, for example, a switch, a remote controller, or setting means, and the control means 7 corrects the zero point of the measuring means 5 of the flow path having the opening / closing means 4 closed by this signal. .
[0061]
As a result, the user can correct the zero point of the measuring means from the outside at an arbitrary time, and even if a system instability due to sudden disturbance or the like occurs, the user manually corrects the zero point. A signal can be transmitted.
[0062]
Furthermore, as an external signal source that generates a signal for requesting correction of the zero point, it is also possible to use equipment installed on the downstream side of the outflow path, for example, a gas water heater 27 if it is a gas appliance. When the gas flow rate is estimated by a gas flow rate measuring unit or the like in the gas water heater, and it is determined that a fluid (here, gas) below a certain level is flowing, the zero point is set via the communication unit 26 to the control unit 7 of the flow rate measuring device Request correction. This makes it possible to verify the zero point correction with an external signal when the fluid flow rate is small.
[0063]
Similarly, the external signal source may be a device installed on the upstream side of the inflow channel 1, for example, a flow rate measuring means 28 of an output unit in a large supply facility. Then, when it is determined that a fluid below a certain level is flowing, this flow rate measuring means requests the zero point correction operation to the control means 7 of the flow rate measuring apparatus via the communication means 26. This makes it possible to verify the zero point correction with an external signal when the amount of fluid is surely small. Further, the external signal itself may be a device having a timekeeping means inside, or a device centralized meter reading board. This makes it possible to request zero point correction within a certain time from the outside.
[0064]
In addition, although it demonstrated over Example 1 thru | or 6 example about this invention, it cannot be overemphasized that these Examples can combine two or more. Further, the zero point is corrected only when it is determined that the value of the flow rate calculation means indicates an abnormal value, so that unnecessary zero point correction is not performed, and power consumption can be reduced. A person skilled in the art can easily realize an embodiment corresponding to the time of leakage of a minute fluid by determining that the zero value has changed when the flow rate is equal to or less than a predetermined flow rate value and performing zero correction.
[0065]
And by using a plurality of channels, it is possible to measure the flow rate from a minute flow rate to a large flow rate, and to always measure the flow rate with high accuracy by verifying the zero point of the measuring means in the closed flow channel. It will be. Further, periodically operating the opening / closing means can prevent the opening / closing means from adhering to the flow path, and can further improve the reliability.
[0066]
【The invention's effect】
As described above, according to the flow rate measuring apparatus of the present invention, the following effects can be obtained.
[0067]
(1) In a configuration having a plurality of flow paths, even if the flow rate is not traceable, the zero point of the flow path where the flow rate is not measured is corrected, and the zero point correction is completed by switching the opening / closing means. Fluid measurement can be performed in the flow path. For this reason, when the flow path is opened, the measurement system has good stability, enables measurement without deviation of the zero point, and prevents the accuracy from becoming unstable.
[0068]
(2) By using a method for transmitting and receiving ultrasonic signals provided in the flow path as a measuring means, the flow rate is measured without disturbing the flow of the fluid, and a plurality of flow paths are combined to instantly in a wide range. The flow rate can be measured with high accuracy.
[0069]
(3) The measuring means in the closed state has already been corrected for the zero point, and even if there is a change in the zero point due to a change over time in the measuring means in the flow path during the flow rate measurement, By switching the path, it is possible to perform measurement with good stability and no zero point deviation within a certain time, and it is possible to prevent the accuracy from becoming unstable.
[0070]
(4) If it is determined that the fluid flow rate is equal to or lower than the predetermined flow rate in the flow rate determining means, the flow of fluid is small and the disturbance from the downstream is small, so that the error due to the influence from the downstream in the flow path closing the opening and closing means It becomes possible to perform the zero point test without including it.
[0071]
(5) If it is determined that the fluid flow rate is higher than the predetermined flow rate in the flow rate determination means, the zero point correction operation of the measurement means in the dew flow that is closed by a large flow rate disturbance from the downstream side may be adversely affected. Since there is a high possibility that it is necessary to open the opening and closing means to measure the flow rate, and to flow the fluid through the flow path, stopping the zero point verification makes it possible to measure the flow rate more quickly without reducing the accuracy of the zero point. It will be possible to prepare for this.
[0072]
(6) The zero point can be corrected at regular intervals by measuring means in the flow path where the opening / closing means is closed by the timer means, and the deviation of the zero point due to changes over time due to disturbances such as temperature and humidity occurs. Even within a certain period of time, it becomes possible to reduce the fluctuations, and even if the flow rate suddenly increases and the flow path must be opened and used, it can sufficiently cope with it. .
[0073]
(7) Measure the flow rate peculiar to the system where the flow measurement device is installed in advance, for example, set the timing means when the flow is low, and optimize the precision of the measurement means by correcting the zero point at that time It becomes possible to adjust to the correct time.
[0074]
(8) The time at which a stable flow rate equal to or lower than a constant flow rate is continuously stored in the storage unit by the time measuring unit, and the operation for correcting the zero point of the measuring unit in the closed flow path is stored in the storage unit. It is possible to adjust the measuring means more accurately by examining the zero point state of the measuring means in a stable state time considering the unique usage conditions and conditions attached to the system. Become.
[0075]
(9) By using the communication means, the user can correct the zero point of the measuring means from the outside at an arbitrary time, and even if a system instability due to sudden disturbance occurs, the zero point is manually set. It is possible to send a signal for correcting the above.
[Brief description of the drawings]
FIG. 1A is a block diagram showing a flow rate measuring apparatus according to a first embodiment of the present invention.
(B) Schematic diagram of flow rate detection means of the apparatus
FIG. 2 is a block diagram showing measurement means of the apparatus
FIG. 3 is a block diagram showing control means of a flow rate measuring device according to Embodiment 2 of the present invention.
FIG. 4A is a timing chart showing the operation of the opening / closing means 4a of the apparatus.
(B) Timing chart showing the operation of the opening / closing means 4b of the apparatus.
(C) Timing chart showing the operation of the opening / closing means 4c of the apparatus
(D) Timing chart showing the operation of the first timer means of the apparatus
FIG. 5 is a block diagram showing control means of a flow rate measuring device according to Embodiment 3 of the present invention.
FIG. 6 is a timing chart showing processing of control means of the apparatus
FIG. 7 is a block diagram showing a control means of a flow rate measuring device in Embodiment 4 of the present invention.
FIG. 8A is a timing chart showing the operation of the opening / closing means 4a of the apparatus.
(B) Timing chart showing the operation of the opening / closing means 4b of the apparatus.
(C) Timing chart showing the operation of the second timer means of the apparatus
FIG. 9 is a block diagram showing control means of a flow rate measuring device according to Embodiment 5 of the present invention.
FIG. 10 is a block diagram showing control means of a flow rate measuring device in Embodiment 6 of the present invention.
[Explanation of symbols]
1 Inflow channel
2 Outflow channel
3 Flow path
4 Opening and closing means
5 Measuring means
6 Zero point test method
7 Control means
10 First vibrator
11 Second vibrator
12 Transmission means
13 Receiving means
20 Flow rate calculation means
21 First timer means
22 Flow rate judging means
23 Second timer means
24 Timekeeping
25 Memory means
26 Communication means

Claims (2)

A plurality of flow paths provided between the inlet and the outlet;
A plurality of opening / closing means for individually opening and closing the plurality of flow paths;
Measuring means for individually measuring the flow rates of the plurality of flow paths;
And a control means for controlling said measuring means and said switching means,
The measuring means includes a first vibrator and a second vibrator that transmit and receive an ultrasonic signal provided in the flow path, a transmission circuit that sends periodic drive vibration to the vibrator, and an ultrasonic wave between the vibrators. and a flow rate calculation means for calculating a flow rate based on the propagation time,
The control means, the signal of the zero-point assay means for detecting zero-value correction zero value of the measuring means, the flow path being open flow rate calculating means in the flow path of the switching means is closed is A flow rate measuring device comprising: a flow rate determining means for sending a signal for starting zero value correction to a zero point verification means for a closed channel when the flow rate is lower than a predetermined flow rate. A plurality of flow paths provided between the inlet and the outlet;
A plurality of opening / closing means for individually opening and closing the plurality of flow paths;
Measuring means for individually measuring the flow rates of the plurality of flow paths;
Control means for controlling the opening and closing means and the measuring means,
The measuring means includes a first vibrator and a second vibrator that transmit and receive an ultrasonic signal provided in the flow path, a transmission circuit that sends periodic drive vibration to the vibrator, and an ultrasonic wave between the vibrators. Flow rate calculation means for calculating the flow rate based on the propagation time of
The control means includes a zero point verification means for detecting a zero value of the measuring means in the flow path in which the opening / closing means is closed and correcting the zero value, and a flow rate of the flow path opened during the zero point detection. A flow rate measurement device comprising: a flow rate determination unit that sends a signal for stopping zero value correction to a zero point verification unit of a closed flow path when the signal of the calculation unit exceeds a predetermined flow rate.

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