JP2003121221A - Method of measuring flow rate, and ultrasonic flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic flow measuring method and its method capable of measuring a flow rate with a time interval suitable to the flow rate, thereby suppressing an electric power consumption to the minimum. SOLUTION: In the flow measuring method and device for transmitting an ultrasonic wave to the fluid to measure the flow rate of the fluid based on a propagation time up to reception of the ultrasonic wave, a measuring time interval for measuring the flow rate is set, based on time information. In the method and device, the measuring time interval is preferably reset on the basis of consumption information of the fluid when the measuring time interval is set, based on the time information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas or liquid flow rate measuring method using ultrasonic waves, and an ultrasonic flowmeter for executing the measuring method.

[0002]

BACKGROUND OF THE INVENTION An ultrasonic flow meter is disclosed in U.S. Pat. No. 4,483,202. This flow meter includes a conduit through which a fluid flows and a pair of ultrasonic transducers provided in the conduit on a line that obliquely intersects the direction in which the fluid flows. In the operation, first, an ultrasonic wave is transmitted from the ultrasonic transducer arranged on the upstream side in the flow direction toward the downstream side, and the ultrasonic wave is received by the ultrasonic transducer on the downstream side. Then, the propagation time from transmission to reception is required. next,
Ultrasonic waves are transmitted from the ultrasonic transducers arranged on the downstream side in the flow direction toward the upstream side, are received by the ultrasonic transducers on the upstream side, and the propagation time from the transmission to the reception is obtained. Then, by substituting these two propagation times into a known formula, the flow velocity of the fluid is obtained, and the flow velocity is obtained using the flow velocity.

However, in the known ultrasonic flowmeter as described above, ultrasonic waves are transmitted at regular time intervals regardless of the flow rate to measure the flow velocity and flow rate. Therefore, the conventional ultrasonic flowmeter has a problem that the power consumption is large and the battery is consumed in a short period when driven by the battery.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultrasonic flow rate measuring method and apparatus capable of measuring a flow rate at time intervals suitable for the flow rate and thereby minimizing power consumption. To do.

In order to achieve this object, the present invention provides a flow rate measuring method in which an ultrasonic wave is transmitted to a fluid and the flow rate of the fluid is measured based on a propagation time until the ultrasonic wave is received. The measurement time interval for measuring the flow rate is set from the time information. In this flow rate measuring method, when the measurement time interval is set from the time information, it is preferable to reset the measurement time interval based on the fluid consumption information.

Another aspect of the present invention is a flow rate measuring method for transmitting a ultrasonic wave to a fluid and measuring the flow rate of the fluid based on a propagation time until the ultrasonic wave is received. It is characterized by setting a delay time. In this flow rate measuring method, when the delay time is set from the time information, it is preferable to reset the delay time based on the fluid consumption information. Further, it is preferable that the time information is information about time or information about date.

The ultrasonic flowmeter of the present invention is provided in a conduit through which a fluid flows, and a transmitter for transmitting ultrasonic waves to the fluid,
A receiver that is provided in the conduit on the upstream side or the downstream side of the transmitter with respect to the flow direction of the fluid and that receives the ultrasonic wave, and the propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, A flow rate calculation unit that obtains a flow rate from the propagation time, and a timing control unit that determines an operating state of a fluid consuming device to which the conductor is connected and sets a measurement time interval for measuring the flow rate according to the operating state. It is characterized by having.

An ultrasonic flowmeter according to another aspect of the present invention is provided with a conduit through which a fluid flows and which transmits an ultrasonic wave to the fluid, and an upstream side or a downstream side of the transmitter with respect to the flow direction of the fluid. In the conduit, a receiver for receiving the ultrasonic wave, a flow rate calculation unit for determining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and a flow rate from the propagation time, and the conductor. And a timing control unit that determines the operating state of the fluid consuming device connected to and set the delay time according to the operating state.

An ultrasonic flowmeter according to another aspect of the present invention is provided with a conduit through which a fluid flows and which transmits an ultrasonic wave to the fluid, and an upstream side or a downstream side of the transmitter with respect to the flow direction of the fluid. In the above-mentioned conduit, a receiver for receiving the ultrasonic wave, a flow rate calculation unit for obtaining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and for obtaining a flow rate from the propagation time, It is characterized by having a clock unit that outputs at least one time information of day or time, and a timing control unit that sets a measurement time interval for measuring the flow rate according to the information from the clock unit.

An ultrasonic flowmeter according to another aspect of the present invention is provided with a conduit through which a fluid flows and which transmits an ultrasonic wave to the fluid, and an upstream side or a downstream side of the oscillator with respect to the flow direction of the fluid. In the above-mentioned conduit, a receiver for receiving the ultrasonic wave, a flow rate calculation unit for obtaining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and for obtaining a flow rate from the propagation time, A clock unit that outputs at least one time information of day or time, and a timing control unit that sets a delay time that delays the output of the trigger signal for transmitting the ultrasonic wave according to the information from the clock unit. It is characterized by having.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a control block diagram of the ultrasonic flowmeter according to the first embodiment, and the ultrasonic flowmeter is indicated by reference numeral 1 as a whole. In the flow meter 1, reference numeral 2 indicates a conduit having a circular cross section connected to a gas combustion device (not shown), and a fluid, that is, a gas to be supplied to the combustion device flows in the conduit 2 in the direction of arrow 4. . Reference numeral 6 is a vibrator (transmitter) that transmits ultrasonic waves, and reference numeral 8 is a vibrator 6
The ultrasonic transducers (receivers) for receiving the ultrasonic waves transmitted from are shown so that these transducers 6 and 8 face each other on a line 12 that intersects the central axis 10 of the conduit 2 at a predetermined angle φ. Respectively attached to the conduits 2. Reference numeral 14 indicates a trigger unit, which outputs a trigger signal at a timing determined by a method described later. Reference numeral 16 indicates a transmitter, and the transmitter 16 outputs a burst signal for driving the vibrator 6 when receiving the trigger signal. Reference numeral 18 denotes an amplifier, which amplifies a signal transmitted when the vibrator 8 detects an ultrasonic wave. Reference numeral 20 indicates a comparison unit, which creates and outputs a signal corresponding to the time (propagation time) from when the transducer 6 transmits an ultrasonic wave to when the transducer 8 receives the ultrasonic wave. Reference numeral 22 indicates a timekeeping section,
The clock unit 22 calculates and calculates the propagation time from the output signal of the comparison unit 20. Reference numeral 24 is a flow rate calculation unit, and this flow rate calculation unit 24 calculates the flow rate of the fluid flowing in the conduit 2 from the propagation time based on the calculation described later. Code 2
Reference numeral 6 denotes a timing control unit, which is the timing control unit 26.
Determines the timing at which the trigger unit 14 outputs the trigger signal from the flow rate.

In the present embodiment, the above timing is obtained as a measurement time interval from the relationship (characteristic curve) between the flow rate and the measurement time interval shown in FIG. 2, and the measurement time interval becomes shorter as the flow rate increases. Is set.

The operation of the flow meter 1 will be described. Trigger unit 14
When the trigger signal is output from, the transmitter 16 creates a burst signal based on the signal and outputs the burst signal. The vibrator 6 is driven by the burst signal and emits ultrasonic waves toward the vibrator 8. This ultrasonic wave is received by the vibrator 8, and the received signal is amplified by the amplifier 18. Next, the comparison unit 20 creates a signal corresponding to the ultrasonic wave propagation time and outputs this to the timer unit 22. The timer 22 calculates the propagation time, and the flow rate calculator 24 calculates the flow rate from the propagation time. Subsequently, the timing control unit 26 obtains the measurement time interval corresponding to the flow rate obtained from the relationship of FIG. Specifically, if the flow rate measured this time is higher than the flow rate measured last time, the measurement time interval is set short,
On the contrary, if it decreases, the measurement time interval is set longer. Subsequently, the trigger unit 14 outputs a trigger signal at a newly set measurement time interval to drive the vibrator 6, and the vibrator 8 detects the ultrasonic wave transmitted from the vibrator 6 to detect the flow rate. Is measured. After that, the same processing is repeated.

As described above, in a device such as a gas meter that needs to accurately calculate the integrated flow rate, a measurement error when the flow rate is large has a great influence on the integrated value. Accurate integrated values are obtained as often as possible.

The calculation of the propagation time in the clock unit 22 will be described. When the velocity of ultrasonic waves transmitted through a stationary fluid is c and the velocity of fluid flow is v, the velocity of ultrasonic wave propagation along the flow direction is (c + v). The ultrasonic wave propagation time t from the oscillator 4 to the oscillator 5 is given by the following equation (1).

T = L / (c + v.cosφ) (1) In the equation (1), L is the distance between the vibrators 6 and 8.
The equation (1) can be transformed into the following equation (2). v = L / (c−v · cos φ) (2) Here, since L and c are known, the flow velocity can be obtained by measuring the propagation time t. Further, the flow rate Q is expressed by the following equation (3)
Given in. Q = K · S · v (3) In equation (3), the cross-sectional area of the conduit 2 is S and the correction coefficient is K.
Is. By the way, the relationship between the flow rate and the measurement time interval may be such that the measurement time interval gradually decreases as the flow rate increases as shown in FIG. It may be inversely proportional to.

In the first embodiment, the timing control section 26 determines the measurement time interval from the measured flow rate based on the preset relationship between the flow rate and the measurement time interval. The delay time of the trigger signal to be output may be obtained, and the trigger unit 14 may be driven after the delay time has elapsed.

As for the relationship between the flow rate and the delay time, if the delay time generally decreases as the flow rate increases,
It may be a linear relationship (FIG. 5), a stepwise relationship (FIG. 6), or an inverse proportional relationship (FIG. 7).

Second Embodiment: FIG. 8 shows an ultrasonic flowmeter 1A of the second embodiment, which has many common components with the ultrasonic flowmeter of FIG. 1, and these common components are similar. Since they achieve the function, they are denoted by common symbols. However, this ultrasonic flowmeter 1A has a storage unit 28 for storing flow rate data storage.
Has been added. In the storage unit 28, the flow rate calculation unit 2
A predetermined number of flow rate values calculated in step 4 are sequentially stored as flow rate data, and the latest flow rate data is replaced with the oldest flow rate data to update the data. Further, based on the average value of the stored plural flow rate data, the timing control unit 30 sets the measurement time interval or the delay time from the relationships of FIGS. 2 to 4 and FIGS. 5 to 7, respectively.

The relationship between the flow rate and the measurement time interval or delay time is preferably corrected in consideration of whether the flow rate is currently increasing or decreasing. For example, the timing control unit 30 determines whether the flow rate is currently increasing or decreasing based on the flow rate data stored in the storage unit 28, as shown in the flowchart of FIG. 9. Then, when the flow rate is increasing, it is corrected to be shorter than the measurement time interval or delay time for the same flow rate when the flow rate is stable, and when the flow rate is decreasing, the delay time is corrected to be longer and corrected. A trigger signal is output based on the measured time interval or delay time. The relationship between the flow rate corrected in this way and the measurement time interval or delay time is shown in FIG. According to such flow rate correction, there is an advantage that the increase amount of the flow rate can be accurately measured, for example, when the flow rate rapidly increases.

Third Embodiment: FIG. 11 shows an ultrasonic flowmeter 1B of the third embodiment, which has many common components with the ultrasonic flowmeter of FIG. 1, and these common components are similar. Since they achieve the function, they are denoted by common symbols. This ultrasonic flowmeter 1B is generally provided with a function of changing the measurement time interval or the delay time depending on the time period when gas is consumed and the time period when gas is not consumed. Specifically, the ultrasonic flow meter 1B
Is provided with a clock 32, and the current time output from this clock 32 is output to the timing control unit 34. As shown in the flowchart of FIG. 12, the timing control unit 34 determines from the time information whether or not the present time is in the mass gas consumption time zone. For example, the midnight time zone from midnight to 5 am is set as the low gas consumption time zone, and the other time zones are set as the high gas consumption time zones, and it is determined which time zone the current time belongs to. . If it is determined that the current time is the low gas consumption time zone, the measurement time interval (or delay time) is set to a predetermined long time. The measurement interval time or delay time set here is unique, unlike the time calculated from the flow rate based on the relationship of FIGS. 2 to 4 (or FIGS. 5 to 7). Next, it is determined whether or not the flow rate has changed, and if there is a change in the flow rate, based on the newly obtained flow rate, the measurement time interval based on the relationship of FIGS. 2 to 4, or the relationship of FIGS. 5 to 7. Sets a new delay time.

According to this embodiment, the measurement time interval or the delay time is set longer in the midnight time when the gas is not used, and unnecessary electricity consumption is suppressed. Further, even when the gas is consumed even at midnight, the flow rate is measured with a measurement time interval or delay time according to the flow rate.

Further, in an area where the consumption of fluid such as gas differs depending on the season, the date and time information may be output from the clock instead of or together with the time, and the flow rate measurement may be controlled with reference to this information. Good.

Fourth Embodiment: FIG. 13 shows an ultrasonic flowmeter 1C of the fourth embodiment, which has many common components with the ultrasonic flowmeter of FIG. 1, and these common components are similar. Since they achieve the function, they are denoted by common symbols. In this ultrasonic flowmeter 1C, the operation states of devices that consume gas, for example, the stove 36, the stove 38, and the water heater 40 are input to the timing control unit 42. The timing control unit 42 determines whether the gas consuming device 36, 38, or 40 is stopped, as shown in the flowchart of FIG. Then, when it is determined that all the gas consuming devices are stopped, the measurement time interval (or delay time) is set to a predetermined long time. The measurement interval time (or delay time) set here is unique unlike the time obtained from the flow rate based on the relationships of FIGS. 2 to 4 (FIGS. 5 to 7). Next, it is determined whether or not the flow rate has changed, and if there is a change in the flow rate, based on the newly obtained flow rate, the measurement time interval based on the relationship of FIGS. 2 to 4, or the relationship of FIGS. 5 to 7. Sets a new delay time. According to this embodiment, when the gas is not consumed, the measurement time interval or the delay time is set longer, so that unnecessary electricity consumption is suppressed.

Fifth Embodiment: FIG. 15 shows an ultrasonic flowmeter 1D of the fifth embodiment, which has many common components with the ultrasonic flowmeter of FIG. 1, and these common components are similar. Since they achieve the function, they are denoted by common symbols. In this ultrasonic flowmeter 1D, the transducers 44 and 46, which have both functions of transmitting and receiving ultrasonic waves, are arranged so as to oppose each other on a line 12 that intersects the central axis 10 of the conduit 2 at a predetermined angle φ. Two
It is attached to. The transducer switching unit 48 alternately switches the transducer between the ultrasonic wave transmitting state and the ultrasonic wave receiving state. The repeat count setting unit 50 sets the repeat count for transmitting ultrasonic waves by the transducers 44 and 46. Repeat control unit 52
Is a first oscillator in which ultrasonic waves are transmitted from one transducer 44 a number of times corresponding to the flow rate and ultrasonic waves are received by the other transducer 46.
The state is switched to the second state in which the other transducer 46 transmits ultrasonic waves the same number of times and the one transducer 44 receives ultrasonic waves, and vice versa. The relationship between the flow rate and the number of repetitions is set such that the number of repetitions generally decreases as the flow rate increases.

The operation of the flow meter 1D will be described in detail with reference to the flowchart of FIG. Now, assuming that the number of repetitions is set to n by the repetition setting unit 50, the switching unit 48 sets the first state. Next, the trigger unit 14 outputs a trigger signal and the transmitter 16 outputs a burst signal. As a result, ultrasonic waves are transmitted from the oscillator 44 to the other oscillator 46 with a predetermined delay time. The signal received by the oscillator 46 is amplified by the amplifier 18, and compared with the reference signal by the comparator 20. In addition, the ultrasonic wave propagation time is calculated by the clock unit 22. Then, it is determined whether the ultrasonic wave is transmitted n times from the vibrator 44. Then, if ultrasonic waves have already been transmitted n times, n
The ultrasonic wave propagation times are accumulated. On the other hand, when the number of ultrasonic wave transmissions is less than n, the trigger unit 14 outputs a trigger signal again to execute ultrasonic wave transmission and reception.

When the measurement in the first state is completed, the transducer switching unit 48 is switched to the second state. As a result, the operation of transmitting ultrasonic waves from the vibrator 46 and receiving the ultrasonic waves from the other vibrator 44 is repeated n times, and the ultrasonic wave propagation time of n times is accumulated. Then, the flow rate is calculated from the cumulative values of the propagation times in the first state and the second state or their average values. Next, the newly obtained flow rate is compared with the previously obtained flow rate to determine whether the flow rate is increasing or decreasing, and the repeat setting unit 50 sets the number of repetitions according to the newly obtained flow rate. It The number of repetitions set here is such that the number of repetitions generally decreases as the flow rate increases, and the flow rate can be accurately measured even if the flow rate is small.

The flow velocity and flow rate calculation in this embodiment will be described. Assuming that the velocity c of the ultrasonic wave in the stationary fluid is v and the flow velocity of the fluid is v, the ultrasonic velocity in the forward direction of the flow is (c +
v), the ultrasonic wave velocity in the opposite direction is given by (cv). The cumulative propagation time T1 in the forward direction and the cumulative propagation time T2 in the reverse direction are given by equations (4) and (5), respectively.

[0029] In these equations (4) and (5), φ is the angle of intersection between the center line of the conduit and the line connecting the transducers, and n is the number of repetitions. Also,
From these equations (4) and (5), the cumulative total of the flow velocity measurement values is given by the following equation (6). (v ₁ + ·· + v _n ) = L · n · (1 / T1-1 / T2) / 2 · cos φ (6) Further, the cumulative flow velocity value is given by the following formula (7) from the formula (6). To be ΣQn = K · S · (v ₁ + ·· + v _n ) (7) In this equation (7), ΣQn is the cumulative flow velocity value, K is the correction coefficient, and S is the cross-sectional area of the conduit.

As is apparent from these equations (6) and (7), the cumulative value of the flow rate value increases as the number of times of measurement increases. In other words, even if the flow velocity is small, if the number of times of measurement is increased, the cumulative total of the flow velocity value and the flow amount value becomes large, and the error included in each measurement becomes small. Conversely, when the flow velocity is high, T1
And T2 are large, the relative measurement error is small even if the number of measurements is reduced. For this reason, in the present invention, the repeat count setting unit 50 increases the repeat count when the flow rate is low and decreases the repeat count when the flow rate is high. It should be noted that the relationship between the flow rate and the number of repetitions may be such that the number of repetitions generally decreases as the flow rate increases, so that the number of repetitions decreases linearly, stepwise, or inversely with respect to the flow rate. Set to. In the above description, it is assumed that the oscillator transmits n ultrasonic waves and then the oscillator transmits n ultrasonic waves.
After the ultrasonic wave is transmitted once from the vibrator,
The operation of transmitting the ultrasonic waves may be repeated a number of times.

Sixth Embodiment: FIG. 17 shows an ultrasonic flowmeter 1E of the sixth embodiment, which has many common components with the ultrasonic flowmeter of FIG. 1, and these common components are similar. Since they achieve the function, they are denoted by common symbols. This flow meter 1
E includes a power cutoff unit 54, and as shown in the flowchart of FIG. 18, a plurality of flow rate values obtained by the flow rate calculation unit 24 are stored in the storage unit 56 as flow rate data. Also,
When the flow rate is determined to be zero from the flow rate data in the storage unit 56, the number of times of such continuous determination is stored.
When the determination of zero flow rate continues for a predetermined number of times, the power cutoff unit 54 is driven, and the trigger unit, the transmission unit 16, the amplification unit 18,
At least one power source of the comparison unit 20, the clock unit 22, or the flow rate calculation unit 24 is shut off for a predetermined time. Therefore, when the fluid is not flowing, the measurement interval becomes long and the power consumption can be saved.

[Brief description of drawings]

FIG. 1 is a control block diagram of an ultrasonic flowmeter according to a first embodiment.

FIG. 2 shows a relationship (characteristic curve) between a flow rate and a measurement time interval, and the measurement time interval linearly decreases as the flow rate increases.

FIG. 3 shows another relationship (characteristic curve) between the flow rate and the measurement time interval, and the measurement time interval gradually decreases as the flow rate increases.

FIG. 4 shows another relationship (characteristic curve) between the flow rate and the measurement time interval, and the measurement time interval decreases in inverse proportion as the flow rate increases.

FIG. 5 shows a relationship (characteristic curve) between the flow rate and the delay time, and the delay time linearly decreases as the flow rate increases.

FIG. 6 shows another relationship (characteristic curve) between the flow rate and the delay time, in which the delay time gradually decreases as the flow rate increases.

FIG. 7 shows another relationship (characteristic curve) between the flow rate and the meter delay time, in which the delay time decreases in inverse proportion as the flow rate increases.

FIG. 8 is a control block diagram of an ultrasonic flowmeter according to a second embodiment.

9 is a part of a control flowchart of the ultrasonic flow meter of FIG.

FIG. 10 shows a relationship (characteristic curve) between a flow rate and a measurement time interval (and a delay time) corrected according to an increase / decrease state of the flow rate.

FIG. 11 is a control block diagram of an ultrasonic flowmeter according to a third embodiment.

FIG. 12 is a part of a control flowchart of the ultrasonic flow meter of FIG. 11.

FIG. 13 is a control block diagram of an ultrasonic flowmeter according to a fourth embodiment.

14 is a part of a control flowchart of the ultrasonic flow meter of FIG.

FIG. 15 is a control block diagram of an ultrasonic flowmeter according to a fifth embodiment.

16 is a control flowchart of the ultrasonic flow meter of FIG.

FIG. 17 is a control block diagram of an ultrasonic flowmeter according to a sixth embodiment.

18 is a control flowchart of the ultrasonic flow meter of FIG.

[Explanation of symbols]

1: Flow meter 2: conduit 6: Ultrasonic transducer (transmitter) 8: Ultrasonic transducer (receiver) 14: Trigger part 16: Transmitter 18: Amplifier 20: Comparison section 22: Timekeeping section 24: Calculation unit 26: Timing control unit

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 9, 2002 (2002.10.
9)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

The calculation of the propagation time in the clock unit 22 will be described. When the velocity of ultrasonic waves transmitted through a stationary fluid is c and the velocity of fluid flow is v, the velocity of ultrasonic wave propagation along the flow direction is (c + v). The ultrasonic wave propagation time t from the vibrator 6 to the vibrator 8 is given by the following equation (1).

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

T = L (c + vcosφ) (1) In the expression (1), L is the distance between the vibrators 6 and 8.
The equation (1) can be transformed into the following equation (2). v = (L / t−c) / cos φ (2) Here, since L, c, and φ are known, the flow velocity can be obtained by measuring the propagation time t. The flow rate Q is given by the following equation (3). Q = K · S · v (3) In equation (3), the cross-sectional area of the conduit 2 is S and the correction coefficient is K.
Is. By the way, the relationship between the flow rate and the measurement time interval may be such that the measurement time interval gradually decreases as the flow rate increases as shown in FIG. It may be inversely proportional to.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

Second Embodiment: FIG. 8 shows an ultrasonic flowmeter 1A of the second embodiment, which has many common components with the ultrasonic flowmeter of FIG. 1, and these common components are similar. Since they achieve the function, they are denoted by common symbols. However, this ultrasonic flowmeter 1A is additionally provided with a storage unit 28 for storing flow rate data. In the storage unit 28, a predetermined number of flow rate values calculated by the flow rate calculation unit 24 are sequentially stored as flow rate data, and the latest flow rate data is replaced with the oldest flow rate data to update the data. Further, based on the average value of a plurality of stored flow rate data, the timing control unit 3
0 to measure time interval or delay time respectively from FIGS.
It is set from the relationship of FIGS.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

FIG. 7 shows another relationship (characteristic curve) between the flow rate and the delay time, in which the delay time decreases in inverse proportion to the increase in the flow rate.

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Correction target item name] Figure 9

[Correction method] Change

[Correction content]

[Figure 9]

[Procedure correction 6]

[Document name to be corrected] Drawing

[Correction target item name] Figure 15

[Correction method] Change

[Correction content]

FIG. 15

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Correction target item name] Fig. 16

[Correction method] Change

[Correction content]

FIG. 16 ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 25, 2002 (2002.12.
25)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

In order to achieve this object, the present invention provides a flow rate measuring method in which an ultrasonic wave is transmitted to a fluid and the flow rate of the fluid is measured based on a propagation time until the ultrasonic wave is received. The measurement time interval for measuring the flow rate is set from the hour / minute information. In this flow rate measuring method, when the measurement time interval is set from the hour / minute information, it is preferable to reset the measurement time interval based on the fluid consumption information.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Another aspect of the present invention is a flow rate measuring method for measuring the flow rate of the fluid by transmitting ultrasonic waves to the fluid and measuring the flow rate of the fluid until the ultrasonic waves are received. From the above, a delay time for delaying the transmission of the ultrasonic wave is set. In this flow rate measuring method, when the delay time for delaying the transmission of the ultrasonic waves is set from the hour / minute information, the delay time for delaying the transmission of the ultrasonic waves is reset based on the fluid consumption information. Is preferred. Further, it is preferable that the hour / minute information is information on time, information on date, or information on time zone.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

An ultrasonic flowmeter of the present invention is provided with a transmitter provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and provided in the conduit at an upstream side or a downstream side of the transmitter with respect to a flow direction of the fluid. A receiver for receiving the ultrasonic wave, a flow rate calculation unit for determining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and a flow rate from the propagation time, and a fluid consumption device to which the conduit is connected. And a timing control unit for setting a measurement time interval for measuring the flow rate according to the operating state.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

The ultrasonic flowmeter of the present invention is provided with a transmitter provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and provided in the conduit at an upstream side or a downstream side of the transmitter with respect to the flow direction of the fluid. A receiver for receiving the ultrasonic wave, a flow rate calculation unit for determining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and a flow rate from the propagation time, and a fluid consumption device to which the conduit is connected. And a timing control section for setting a delay time for delaying the transmission of the ultrasonic wave according to the operating state.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

An ultrasonic flow meter according to another aspect of the present invention is provided with a transmitter provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and an upstream side or a downstream side of the transmitter with respect to the flow direction of the fluid. A receiver provided in the conduit for receiving the ultrasonic wave, a flow rate calculation unit for determining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and a flow rate from the propagation time, and outputting hourly minute information Clock part to
And a timing control unit that sets a measurement time interval for measuring the flow rate according to information from the clock unit.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

An ultrasonic flowmeter according to another aspect of the present invention is provided with a transmitter provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and an upstream side or a downstream side of the transmitter with respect to a flow direction of the fluid. A receiver provided in the conduit for receiving the ultrasonic wave, a flow rate calculation unit for determining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and a flow rate from the propagation time, and outputting hourly minute information Clock part to
And a timing control unit for setting a delay time for delaying the output of the trigger signal for transmitting the ultrasonic wave according to the information from the clock unit.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenzo Ochi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 2F035 DA19 DA23

Claims (10)

[Claims] 1. A flow rate measuring method for measuring the flow rate of a fluid by transmitting ultrasonic waves to the fluid and measuring the flow rate of the fluid based on the propagation time until the ultrasonic waves are received. A flow measurement method characterized by setting a time interval. 2. The measurement time interval is set based on the fluid consumption information when the measurement time interval is set from the time information, when the fluid is consumed. Flow measurement method. 3. A delay time is set from time information in a flow rate measuring method for measuring a flow rate of the fluid based on a propagation time until the ultrasonic wave is transmitted to the fluid and the ultrasonic wave is received. A flow rate measuring method characterized by. 4. The flow rate according to claim 3, wherein when the delay time is set from the time information, when the fluid is consumed, the delay time is set based on the fluid consumption information. Measuring method. 5. The flow rate measuring method according to claim 1, wherein the time information is information regarding time. 6. The flow rate measuring method according to claim 1, wherein the time information is information regarding a date. 7. A transmitter provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and an ultrasonic wave provided in the conduit upstream or downstream of the transmitter with respect to the flow direction of the fluid. A receiver for receiving, a flow rate calculation unit for obtaining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and a flow rate from the propagation time, and an operating state of a fluid consuming device to which the conductor is connected. An ultrasonic flow meter, comprising: a timing control unit that determines and sets a measurement time interval for measuring the flow rate according to the operating state. 8. A transmitter provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and a conduit provided in the conduit upstream or downstream of the transmitter with respect to the flow direction of the fluid. A receiver for receiving, a flow rate calculation unit for obtaining a propagation time for the ultrasonic wave to propagate from the transmitter to the receiver, and a flow rate from the propagation time, and an operating state of a fluid consuming device to which the conductor is connected. An ultrasonic flowmeter, comprising: a timing control unit that makes a determination and sets a delay time according to the operating state. 9. An oscillator provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and an ultrasonic oscillator provided in the conduit upstream or downstream of the oscillator with respect to a flow direction of the fluid. A receiver for receiving, a flow rate calculation unit for obtaining a propagation time of the ultrasonic wave propagating from the transmitter to the receiver, and a flow rate from the propagation time, and outputting at least one time information of date and time. An ultrasonic flowmeter, comprising: a clock unit for controlling the flow rate; and a timing control unit for setting a measurement time interval for measuring the flow rate according to information from the clock unit. 10. An oscillator provided in a conduit through which a fluid flows and transmitting ultrasonic waves to the fluid, and an oscillator provided in the conduit upstream or downstream of the oscillator with respect to the flow direction of the fluid. A receiver for receiving, a flow rate calculation unit for obtaining a propagation time of the ultrasonic wave propagating from the transmitter to the receiver, and a flow rate from the propagation time, and outputting at least one time information of date and time. An ultrasonic flowmeter, comprising: a clock unit for controlling the operation and a timing control unit for setting a delay time for delaying the output of the trigger signal for transmitting the ultrasonic wave according to the information from the clock unit.