JPH08136324A - Flow-rate compensation device of gas meter - Google Patents

Abstract

PURPOSE: To eliminate the need for a complex mechanical flow-rate compensation treatment and at the same time accurately compensate flow rate even if the operating speed of a mechanical movable part changes during one cycle when a flow rate is constant in a gas meter with the mechanical movable part. CONSTITUTION: A circular plate 51 rotates at a rate corresponding to a gas flow rate and a pulse with a cycle corresponding to a flow rate is generated by a waveform-shaping circuit 55. In a flow-rate compensating device, a pulse counter 61 measures the number of pulses in a specific amount of time which is counted by a timer 62 and an average pulse cycle operation part 63 calculates an average pulse cycle. Then, a flow-rate operation part 64 calculates a compensated flow rate based on the average pulse cycle by referring to a table 65 for expressing the relationship between the average pulse cycle and the compensated flow rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate correction device for a gas meter for correcting different instrumental differences depending on the flow rate.

[0002]

2. Description of the Related Art Generally, in a gas meter, if the flow rate (flow velocity) passing through the gas meter is different, the instrumental difference is different. Here, the instrumental error refers to the difference between the indicated flow rate of the reference instrument and the indicated flow rate of each gas meter, expressed as a percentage of the indicated flow rate of each gas meter. Further, in the gas meter, a measurement error due to the mechanism also occurs depending on the fluid passage amount during the test. Therefore, for gas meters, conduct a test with the flow rate (verification flow rate) and passage rate according to the maximum usable flow rate or number indicated on the gas meter, and correct the gas meter so that the instrumental error is within the verification tolerance. It is defined by the Measurement Law.

FIG. 10 is a characteristic diagram showing the test tolerance. As shown by the diagonal lines in this figure, the verification tolerance is 2.5% for flow rates of 1/20 or more and less than 1/5 of the maximum flow rate,
For flow rates of 1/5 or more and less than 4/5 of the maximum flow rate, 1.
5%, 2.5% for flow rates above 4/5 of maximum flow rate
Has become.

Therefore, conventionally, the instrumental difference is measured at two points of the maximum flow rate and the verification flow rate (about 30% of the maximum flow rate), and the number of teeth and the rotation timing of the gear in the mechanical movable part that moves according to the flow rate are measured. The gas meter was manufactured by making mechanical corrections such as changing.

[0005]

However, the above-described correction method requires a step of performing a complicated mechanical correction process such as gear replacement for correcting the instrumental error on the manufacturing line, and thus the gas meter. In addition to the increase in cost, there is a risk that defective products may be generated due to incorrect operation.

Further, as a method for measuring the flow rate in a gas meter having a mechanically movable portion such as a membrane gas meter, one cycle of the operation of the mechanically movable portion is disclosed, for example, as disclosed in JP-A-5-107096. A disk that makes one rotation in conjunction with the disk is provided, and a plurality of magnets provided on the disk and a magnetoresistive element provided in the vicinity of the disk are used during one cycle of the operation of the mechanical movable part. To output multiple pulses,
There is a method of calculating the flow rate from the frequency and period of this pulse. Then, in the gas meter for measuring the flow rate in this way, as shown in, for example, Japanese Patent Laid-Open No. 58-34321, the period of the pulse is measured, and the correction process is performed for each period of the pulse to perform the correction. It is conceivable to calculate the flow rate.

However, in a membrane gas meter or the like, even if the flow rate is constant, the speed of the disk interlocking with the mechanically movable portion may change during one rotation, for mechanical reasons. In such a case, even if the flow rate is constant, the pulse cycle changes, so there is a problem in that even if the flow rate is corrected for each pulse cycle as described above, it cannot be corrected accurately. is there.

The present invention has been made in view of the above problems, and an object of the present invention is to eliminate the need for complicated mechanical flow rate correction processing in a gas meter having a mechanically movable portion, and when the flow rate is constant. An object of the present invention is to provide a flow rate correction device for a gas meter that enables highly accurate flow rate correction processing even when the operating speed of the mechanically movable portion changes in one cycle.

[0009]

According to a first aspect of the present invention, there is provided a gas meter flow rate correction device for correcting a measured flow rate in a gas meter having a mechanically movable portion that periodically operates at a speed according to the flow rate. And a pulse output means for outputting a pulse at a plurality of positions in one cycle of the operation of the mechanical movable portion, and an average of the cycle of the pulses output from the pulse output means at a predetermined time interval. An average pulse cycle calculating means for calculating an average pulse cycle which is a value, and a correction according to the average pulse cycle calculated by this average pulse cycle calculating means are performed, and the corrected flow rate is calculated based on the average pulse cycle. And a correction flow rate calculating means.

In this gas meter flow rate correction device, the pulse output means outputs pulses at a plurality of positions in one cycle of the operation of the mechanical movable portion, and the average pulse cycle which is the average value of the cycles of the pulses is averaged. It is calculated by the pulse period calculation means. Then, the correction flow rate calculation means performs correction according to the average pulse period,
The corrected flow rate is calculated.

According to a second aspect of the present invention, there is provided a gas meter flow rate correction device which corrects a measured flow rate in a gas meter having a mechanically movable portion which periodically operates at a speed corresponding to the flow rate. A pulse output means for outputting a pulse at a plurality of positions in one cycle of the operation of the mechanical movable part, and a cycle of a pulse output from the pulse output means for each one or a plurality of cycles of the operation of the mechanical movable part. The average pulse cycle calculating means for calculating the average pulse cycle which is the average value of the average pulse cycle and the correction according to the average pulse cycle calculated by the average pulse cycle calculating means, and the corrected flow rate based on the average pulse cycle. And a correction flow rate calculating means for calculating.

In this gas meter flow rate correction device, the pulse output means outputs pulses at a plurality of positions in one cycle of the operation of the mechanical movable part, and the average pulse cycle calculation means calculates the operation of the mechanical movable part. The average pulse period, which is the average value of the periods of the pulses output from the pulse output means, is calculated every one or a plurality of periods. Then, the corrected flow rate calculation means performs correction according to the average pulse period, and calculates the corrected flow rate.

According to a third aspect of the present invention, there is provided a gas meter flow rate correction device according to the first or second aspect, wherein the corrected flow rate calculation means corrects the average pulse period calculated by the average pulse period calculation means. It has a table showing the relationship with the flow rate, and by referring to this table, the corrected flow rate is calculated based on the average pulse period calculated by the average pulse period calculation means.

According to a fourth aspect of the present invention, there is provided a gas meter flow rate correction device according to the first or second aspect, wherein the correction flow rate calculation means calculates the average pulse period and the instrumental error. And a table showing the relationship between the average pulse cycle calculation means and the average pulse cycle calculated by the average pulse cycle calculation means. The corrected flow rate is calculated based on the average pulse period.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 5 relate to a first embodiment of the present invention.

FIG. 1 is a cross-sectional view showing a schematic structure of a membrane gas meter as a gas meter including the flow rate correction device of this embodiment. As shown in the figure, the gas meter has a case body 10, and a gas inlet portion 11 and a gas outlet portion 12 are provided on the upper portion of the case body 10. In addition, inside the case body 10, the front weighing chamber 20 and the rear weighing chamber 3 are provided.
0 is provided.

A membrane 21 is provided in the front measuring chamber 20 at the center in the front-rear direction (the left side in the drawing is the front side), and a membrane plate 22 is attached to the membrane 21. Here, the space in front of the membrane 21 in the front measuring chamber 20 is defined as a chamber, and the space in the rear is defined as a chamber. A gas inlet / outlet portion 23 that communicates with the chamber and a gas inlet / outlet portion 24 that communicates with the chamber are provided at the upper portion of the front measuring chamber 20. A blade shaft 26 is connected to the membrane plate 22 via a blade 25. Wing shaft 2
The reference numeral 6 is adapted to rotate as the membrane 21 moves in the front-rear direction. The blade shaft 26 penetrates through the front measuring chamber 20 and projects upward.

Similarly, in the rear measuring chamber 30, a film 31 is provided at the center in the front-rear direction, and a film plate 32 is provided on the film 31.
Is attached. Here, the space in front of the membrane 31 in the rear measurement chamber 30 is defined as a chamber, and the space in the rear is defined as a chamber. A gas inlet / outlet portion 33 that communicates with the chamber and a gas inlet / outlet portion 34 that communicates with the chamber are provided on the upper portion of the rear measuring chamber 30. A blade shaft 36 is connected to the film plate 32 via a blade. The blade shaft 36 is adapted to rotate as the film 31 moves in the front-rear direction. The blade shaft 36 penetrates the rear measurement chamber 30 and projects upward.

The gas outlet pipe 13 is provided between the gas inlet / outlet portions 23 and 24 and between the gas inlet / outlet portions 33 and 34, respectively.
Is provided. The gas outlet pipe 13 is connected to the gas outlet portion 12. Also, the gas inlet / outlet part 2
A valve 14 is provided on the upper side of 3, 24. The valve 14 has a state in which both the gas inlet / outlet portions 23 and 24 are closed, a state in which the gas inlet / outlet portion 23 and the gas outlet pipe 13 are in communication, and a state in which the gas inlet / outlet portion 24 and the gas outlet pipe 13 are in communication. You can choose. Similarly, the valve 15 is provided above the gas inlet / outlet portions 33 and 34.
Is provided. The valve 15 has a state in which both the gas inlet / outlet portions 33 and 34 are closed, a state in which the gas inlet / outlet portion 33 and the gas outlet pipe 13 are in communication, and a state in which the gas inlet / outlet portion 3 is connected.
4 and the gas outlet pipe 13 are communicated with each other.

An elbow 27 is connected to the upper end of the blade shaft 26, and an elbow 37 is connected to the upper end of the blade shaft 36. These elbows 27 and 37 are connected to the adjusting plate 42 by pins 41. A crank arm 44 and valve arms 45 and 46 are connected to the adjusting plate 42 via a crank pin 43. The crank arm 44 is connected to a crank shaft 47 and is configured to rotate the crank shaft 47. Also, the valve arms 45, 4
6 is connected to the valves 14 and 15, respectively, and moves the valves 14 and 15. A disc 51 (FIG. 3) described later is attached to the crankshaft 47 via a worm and a worm wheel (not shown).

An outline of the operation of the gas meter shown in FIG. 1 will be described with reference to FIG. Weighing room 20,
The introduction of gas into 30 and the discharge of gas from the measuring chambers 20 and 30 are performed by the interlocking action of the valves 14 and 15 and the membranes 21 and 31. The driving force of the movement of the membranes 21 and 31 is the pressure difference between the gas at the gas inlet 11 and the gas outlet 12. In the state shown in FIG. 2A, the valve 14 closes both the gas inlet / outlet portions 23 and 24, and the valve 15 connects the gas inlet / outlet portion 33 and the gas outlet pipe 13. In this state, the gas entering the chamber through the gas inlet / outlet portion 34 pushes the membrane 31 toward the chamber due to the pressure difference, and the gas in the chamber passes through the gas inlet / outlet portion 33, the valve 15 and the outlet pipe 13 in this order, and the gas outlet portion. It is discharged from 12. The movement of the membrane 31 is transmitted in the order of the blade shaft 36, the elbow 37, the adjusting plate 42, and the valve arms 45 and 46, and as shown in FIG. 2B, the valve 14 is moved to the gas inlet / outlet portion 24 and the gas outlet pipe. 1
The valve 15 is moved to a state where it communicates with the valve 3, and the valve 15 is moved to a state where both the gas inlet / outlet portions 33 and 34 are closed. At this time, the gas in the room is the gas inlet / outlet part 23 and the valve 1.
4, the gas passes through the outlet pipe 13 in order and is discharged from the gas outlet 12. Thereafter, similarly, the motion of returning to the state of (a) through the states of FIGS. 2 (c) and (d) is repeated. Further, the crank arm 44 and the crank shaft 47 rotate due to the above movement. Then, the rotation of the crankshaft 47 causes a disc 51 (FIG. 3) described later to rotate via a worm and a worm wheel (not shown).

FIG. 3 is a block diagram showing the circuit configuration of a gas meter including the flow rate correction device of this embodiment. In this figure, reference numeral 51 indicates a disc connected to the crankshaft 47 as described above. The disk 51 is adapted to make one rotation corresponding to one cycle of mechanical operation of the gas meter shown in FIG. A plurality of, for example, five magnets 52 are attached to the disc 51 at equal intervals along the circumferential direction. The gas meter includes a magnetoresistive element 53 which is provided in the vicinity of the disk 51 and detects a change in magnetic field due to the approach and separation of the magnet 52 as a change in resistivity. The gas meter further includes an analog amplifier 54 for amplifying the output signal of the magnetoresistive element 53, a waveform shaping circuit 55 for shaping the output signal of the analog amplifier 54 to generate a pulse, and an output from the waveform shaping circuit 55. A pulse counter 61 that measures the number of pulses that are generated, a timer 62 that measures a predetermined time, and a number of pulses measured by the pulse counter 61 and a predetermined time that the timer 62 measures when the timer 62 measures the predetermined time. The average pulse period calculation unit 63 that calculates the average pulse period that is the average value of the pulse period in a predetermined time, and the average pulse period calculated by the average pulse period calculation unit 63 with reference to the correction table 65. Performs correction according to the cycle and calculates the corrected flow rate and integrated flow rate based on this average pulse cycle Positive arithmetic unit 64, the correction calculating unit 57
And a display unit 59 for displaying the integrated flow rate obtained by. The pulse counter 61, the timer 62, the average pulse period calculation unit 63, the flow rate calculation unit 64, and the correction table 65 are realized by, for example, the microcomputer 60.

In the present embodiment, the correction table 65 stores the relationship between the average pulse period calculated by the average pulse period calculator 63 and the corrected flow rate. here,
The relationship between the average pulse period calculated by the average pulse period calculator 63 and the corrected flow rate will be described with reference to FIG. Since the average pulse period calculated by the average pulse period calculation unit 63 corresponds to the gas flow rate, the gas flow rate can be calculated as “k / average pulse period” with k as a predetermined coefficient. However, this gas flow rate is before correction including instrumental error. FIG. 4 shows an example of the relationship between the uncorrected flow rate and the correct flow rate obtained from the average pulse period in this way. This relationship can be obtained from the indicated flow rate of the gas meter before correction and the indicated flow rate of the reference device. As described above, since the flow rate before correction has a corresponding relationship with the average pulse period, the relationship between the average pulse period and the correct flow rate can be obtained from the relationship shown in FIG. The correction table 65 stores the relationship between the average pulse period thus obtained from the relationship shown in FIG. 4 and the corrected flow rate (correct flow rate).

Next, the operation of the flow rate correcting device of this embodiment will be described with reference to the flow chart of FIG. The gas meter performs the motion shown in FIG. 2 at a speed corresponding to the gas flow rate, and the disk 51 shown in FIG. 3 rotates at a speed corresponding to the gas flow rate with this motion. Then, the magnet 5 provided on the disk 51
The output of the magnetoresistive element 53 changes with the approach and separation of 2, and the output signal of the magnetoresistive element 53 is amplified by the analog amplifier 54 and shaped by the waveform shaping circuit 55.
A pulse having a cycle corresponding to the flow rate is generated. As shown in FIG. 5, the flow rate correction device starts measuring the number of pulses by the pulse counter 61 from the time when the first pulse is output from the waveform shaping circuit 55 (step S 101), and causes the timer 62 to measure a predetermined time. Start timing. Then, it is determined whether or not a predetermined time has elapsed (step S
102), if the predetermined time has not elapsed (N), the process returns to step S102 to continue measuring the number of pulses. When the predetermined time has elapsed (Y), the timer 62 sends a calculation command 71 to the average pulse period calculation unit 63, and in response thereto, the average pulse period calculation unit 63 causes the pulse counter 6
The average pulse period is calculated based on the number of pulses measured by 1 and the predetermined time counted by the timer 62 (step S103). After the arithmetic command 71 is sent to the average pulse period arithmetic unit 63, the reset signal 72 is sent from the timer 62 to the pulse counter 61, and the pulse counter 61 is reset accordingly. Then, the pulse counter 61 starts measuring the number of pulses again, and the timer 62 starts counting a predetermined time. Next, the average pulse period calculator 63 is referred to with reference to the table 65 showing the relationship between the average pulse period calculated by the average pulse period calculator 63 and the corrected flow rate.
The corrected flow rate is calculated based on the average pulse period calculated by (step S104). Then, the integrated flow rate obtained by integrating the corrected flow rates is displayed on the display unit 59.

As described above, according to this embodiment, the corrected flow rate is calculated based on the average pulse period by referring to the correction table 65 showing the relationship between the average pulse period and the corrected flow rate. This eliminates the need for complicated mechanical correction processes such as gear replacement for correcting instrumental differences on the production line, which reduces the cost of the gas meter and prevents malfunctions due to incorrect operation. Since production of non-defective products can be prevented, process control becomes simple.

Further, in the present embodiment, since the flow rate is corrected by referring to the correction table 65, the flow rate can be easily adjusted regardless of the relationship between the flow rate before correction and the correct flow rate as shown in FIG. Can be corrected, and more accurate correction can be performed as compared with mechanical correction.

Further, in this embodiment, the flow rate is corrected and calculated using the average pulse period in a predetermined time, not the period between individual pulses, so that the processing load of the microcomputer 60 is reduced. It In addition, by using the average pulse period, when there is a minute flow rate fluctuation, it is possible to reduce the minute fluctuation that occurs in the calculated flow rate.

Further, in this embodiment, since the flow rate is corrected and calculated by using the average pulse cycle in a predetermined time, the flow rate is constant, but during one cycle of operation for mechanical reasons. Even if the pulse cycle changes, the flow rate can be corrected with high accuracy.

6 and 7 relate to the second embodiment of the present invention. In the present embodiment, the correction table 65 in FIG. 3 is used as a table showing the relationship between the average pulse period calculated by the average pulse period calculation unit 63 and the instrumental error, and the flow rate calculation unit 64 refers to this table, The instrumental difference according to the average pulse period calculated by the average pulse period calculator 64 is obtained, and the corrected flow rate is calculated based on this instrumental difference and the average pulse period calculated by the average pulse period calculator 63. It was done like this.

Here, the relationship between the average pulse period calculated by the average pulse period calculation unit 63 and the instrumental error will be described with reference to FIG. FIG. 6 shows an example of the relationship between the uncorrected flow rate and the instrumental error obtained from the average pulse period calculated by the average pulse period calculation unit 63.
This relationship can be obtained from the indicated flow rate of the gas meter before correction and the indicated flow rate of the reference device. As described above, since the flow rate before correction has a correlation with the average pulse period,
From the relationship shown in FIG. 6, the relationship between the average pulse period and the instrumental error can be obtained. In the correction table 65 in this embodiment,
In this way, the relationship between the average pulse period and the instrumental error obtained from the relationship shown in FIG. 6 is stored.

In the present embodiment, as shown in the flow chart of FIG. 7, the pulse counter 61 starts measuring the number of pulses from the time when the first pulse is output from the waveform shaping circuit 55 (step S201) and the timer. At 62, the clocking of a predetermined time is started. Then, it is determined whether or not a predetermined time has elapsed (step S202), and when the predetermined time has not elapsed (N), the flow returns to step S202 to continue measuring the number of pulses. When the predetermined time has elapsed (Y), the average pulse period calculator 63 and the number of pulses measured by the pulse counter 61 and the timer 6 are used.
The average pulse cycle is calculated based on the predetermined time that 2 counts (step S203). Next, the average pulse cycle calculated by the average pulse cycle calculation section 63 is referred to by the flow rate calculation section 64 with reference to the table 65 showing the relationship between the average pulse cycle calculated by the average pulse cycle calculation section 63 and the instrumental error. The instrumental difference is calculated based on (step S
204). Then, the corrected flow rate is calculated based on the average pulse period calculated by the average pulse period calculation unit 63 and the instrumental error (step S205). When the average pulse period calculated by the average pulse period calculator 63 is T and the instrumental error calculated by referring to the table 65 is E, the corrected flow rate Y is calculated by the following equation. However,
k is a predetermined coefficient.

[0032]

[Formula 1] Y = (k / T) · (1-E / 100)

Other configurations, operations and effects are similar to those of the first embodiment.

FIG. 8 is a block diagram showing the circuit configuration of a gas meter including a flow rate correction device according to the third embodiment of the present invention. In this embodiment, the pulse counter 61 shown in FIG.
For one cycle of mechanical operation of the gas meter, that is, 5
The number of pulses is measured, and the timer 62 measures the time until the pulse counter 61 measures five pulses. The pulse counter 61 sends an operation command 73 to the average pulse period operation unit 63 and sends a reset signal 74 to the timer 62 every time it measures five pulses. The average pulse period calculation unit 63
The average pulse period is calculated based on the number of pulses measured by the pulse counter 61 and the time counted by the timer 62 according to the calculation instruction 73.

Other configurations and operations are the first or second.
This is the same as the embodiment.

According to this embodiment, the average pulse period is calculated for each cycle of mechanical operation of the gas meter, and the flow rate is corrected and calculated using this average pulse period. Even if the pulse period changes during one cycle of operation due to the mechanical reason, it does not appear in the average pulse period even if it is constant, and compared to the case of calculating the average pulse period at an arbitrary time interval. The flow rate can be corrected more accurately. Other effects are similar to those of the first embodiment.

The present invention is not limited to the above-mentioned embodiments. For example, in the third embodiment, the average pulse period may be calculated for every plural cycles of mechanical operation of the gas meter.

The method of correcting the flow rate is not limited to the method using a table. For example, a mathematical expression expressing the corrected flow rate and the instrumental error as a function of the average pulse period is stored, and this mathematical expression is used. The corrected flow rate and instrumental difference may be calculated from the average pulse period.

Further, instead of the magnet 52 and the magnetoresistive element 53, a magnet attached to the movable part of the gas meter and a reed switch which opens and closes depending on the approach and separation of the magnet may be used, or an optical rotary. An encoder or the like may be used.

Further, the flow rate correction device of the gas meter of the present invention is not limited to the membrane type gas meter, but can be applied to other types of gas meters having a mechanically movable part.

[0041]

As described above, according to the gas meter flow rate correction device of the first aspect and the third and fourth aspects of the first aspect, the average pulse period calculation means is used to mechanically operate. The average pulse period, which is the average value of the periods of the pulses output at a plurality of positions in one period of the operation of the movable part, is calculated, and the correction flow rate calculation means performs correction according to the average pulse period to correct the pulse. Since the flow rate is calculated, in a gas meter having a mechanically movable portion, complicated mechanical flow rate correction processing becomes unnecessary, and the operating speed of the mechanically movable portion is constant during one cycle when the flow rate is constant. Even in the case where the value changes with, there is an effect that a highly accurate flow rate correction process can be performed.

Further, according to the flow rate correction device of the gas meter according to any one of claims 2 and 3 and 4 which cites claim 2, the operation of the mechanically movable portion is controlled by the average pulse period calculation means. Since the average pulse cycle is calculated for every one or a plurality of cycles, in addition to the above effect, the flow rate can be corrected more accurately than in the case where the average pulse cycle is calculated at an arbitrary time interval. There is.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a gas meter including a flow rate correction device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an outline of the operation of the gas meter shown in FIG.

FIG. 3 is a block diagram showing a circuit configuration of a gas meter including a flow rate correction device according to a first example of the present invention.

FIG. 4 is a characteristic diagram showing an example of a relationship between a flow rate before correction and a correct flow rate.

FIG. 5 is a flowchart showing the operation of the flow rate correction device according to the first embodiment of the present invention.

FIG. 6 is a characteristic diagram showing an example of the relationship between the flow rate before correction and the instrumental error.

FIG. 7 is a flowchart showing the operation of the flow rate correction device according to the second embodiment of the present invention.

FIG. 8 is a block diagram showing a circuit configuration of a gas meter including a flow rate correction device according to a third embodiment of the present invention.

FIG. 9 is a flowchart showing the operation of the flow rate correction device according to the third embodiment of the present invention.

FIG. 10 is a characteristic diagram showing a test tolerance.

[Explanation of symbols]

 51 Disk 52 Magnet 53 Magnetoresistive Element 55 Waveform Shaping Circuit 61 Pulse Counter 62 Timer 63 Average Pulse Cycle Calculation Unit 64 Flow Rate Calculation Unit 65 Correction Table

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Otani 6-7-9 Yurinokidai, Yachiyo-shi, Chiba (72) Inventor Takashi Ueki 1-1-11-3 Minamikyugahara, Ota-ku, Tokyo (72) Nobuo Negoro Kanagawa Prefecture 1704-2 Izumi-cho, Izumi-ku, Yokohama (72) Inventor Isao Kaneko 3-2-7-221 Takasago, Katsushika-ku, Tokyo (72) Inventor Kazuya Fujisawa 2-5-3-305 Nukii, Nerima-ku, Tokyo (72) ) Inventor Yoshio Yumida 2286-1 Kareshi, Ageo City, Saitama Prefecture (72) Inventor Kyonobu Sato 4-26-17-305 Tokumaru, Itabashi-ku, Tokyo (72) Inventor Kazuro Shimakawa 2-5 Honmachi Nishi, Yono City, Saitama Prefecture -7 (72) Inventor Mineyuki Amate 3-15-7 Asahi-cho, Funabashi City, Chiba Prefecture (72) Inventor Kaoru Maeda 2-8-16 Donobe Chuo, Kamagaya City, Chiba Prefecture (72) Noriyuki Watanabe Nagoya City, Aichi Prefecture 1-270 Millennial, Atsuta-ku Aichi clock Electric Machinery Co., Ltd. (72) Inventor Katsuhisa Hanaki 1-2-70, 1000, Atsuta-ku, Nagoya-shi, Aichi Aichi Clock Electric Co., Ltd.

Claims (4)

[Claims] 1. A gas meter having a mechanically movable part that periodically operates at a speed according to a flow rate, which is a flow rate correction device for a gas meter that corrects a measured flow rate. A pulse output means for outputting a pulse at a plurality of positions in one cycle, and an average pulse cycle calculating means for calculating an average pulse cycle which is an average value of the cycles of the pulses output from the pulse output means at a predetermined time interval. And a correction flow rate calculation means for performing correction according to the average pulse cycle calculated by the average pulse cycle calculation means and calculating the corrected flow rate based on the average pulse cycle. Gas meter flow rate correction device. 2. A gas meter having a mechanically movable part that periodically operates at a speed according to the flow rate, which is a flow rate correction device for a gas meter that corrects the measured flow rate. A pulse output means for outputting a pulse at a plurality of positions in one cycle; and an average pulse which is an average value of the cycle of the pulse output from the pulse output means for each one or a plurality of cycles of the operation of the mechanical movable part. Average pulse cycle calculating means for calculating a cycle, and correction flow rate calculating means for performing correction according to the average pulse cycle calculated by the average pulse cycle calculating means and calculating a corrected flow rate based on the average pulse cycle. A flow rate correction device for a gas meter, comprising: 3. The corrected flow rate calculating means has a table showing the relationship between the average pulse period calculated by the average pulse period calculating means and the corrected flow rate, and referring to this table, the average pulse The flow rate correction device for a gas meter according to claim 1 or 2, wherein the corrected flow rate is calculated based on the average pulse period calculated by the period calculation means. 4. The correction flow rate calculation means has a table showing the relationship between the average pulse cycle calculated by the average pulse cycle calculation means and the instrumental error, and the average pulse cycle calculation is made by referring to this table. It is characterized in that an instrumental difference corresponding to the average pulse period calculated by the means is obtained, and a corrected flow rate is calculated based on the instrumental difference and the average pulse period calculated by the average pulse period arithmetic means. The flow rate correction device for a gas meter according to claim 1.