JPH08136297A - Fluidic type gas meter - Google Patents

Abstract

PURPOSE: To alleviate the measuring error due to the insufficiency of the signal of a fluidic oscillator 'the missing of a pulse' or the excess of a signal 'whisker' of the oscillator when a supply gas pressure is varied. CONSTITUTION: The fluid vibration of a fluidic oscillator is detected by a pressure sensor 10, and shaped to a square wave by a waveform shaper 17. The period of the signal is measured by a period measuring unit 18, compared with a previously decided threshold coefficient, and its varying trend is sequentially obtained. The 'missing of a pulse' or a 'whisker' is recognized from the trend to interpolate the 'missing of the pulse' or the 'whisker'. A changeover switch 27 is operated by the interpolated signal to select the signals from the sensor 10 and a flow sensor 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidic gas meter having means for reducing the occurrence of measurement error due to gas pressure fluctuations.

[0002]

2. Description of the Related Art In Japanese Patent Laid-Open No. 3-96817, there is known a fluidic flowmeter for gas which is convenient for use in a gas meter.

This fluidic flowmeter comprises a fluidic oscillating element for measuring the flow rate in the medium to large flow rate range and a thermal type flow sensor for measuring the flow rate in the small flow rate range.

In the fluidic oscillator, a pair of side walls forms a flow passage expanding portion on the downstream side of the nozzle for generating a jet flow, and a return guide provided on the outside of the side wall allows the fluid passing through the nozzles to be separated from each other. Based on the frequency of this fluid vibration, a pair of feedback channels are formed along the outside of the side wall that lead to the nozzle outlet side, and the fluid that passes through the nozzle alternately flows through the pair of feedback channels. Measure the flow rate of the fluid.

The fluid vibration of the fluidic oscillation element is converted into an electric signal by a pressure sensor and electrically processed. The flow sensor is arranged in the nozzle portion of the fluidic oscillation element and generates an electric signal corresponding to the flow velocity of the nozzle portion. Then, it is driven intermittently at intervals of 6 seconds to measure intermittently.

This gas fluidic flow meter measures the flow rate based on the fluid vibration of the fluidic oscillation element when the period of fluid oscillation of the fluidic oscillation element is less than a certain value, that is, when the flow rate is more than a certain value. When the cycle of the fluid vibration exceeds the fixed value, that is, when the flow rate is less than the fixed value, the pressure sensor and the flow sensor are switched according to the cycle of the fluid vibration so that the flow rate is measured based on the signal of the flow sensor. I am trying.

Further, within a predetermined flow rate range, the flow rate is measured by both the fluidic oscillation element and the flow sensor, and the flow sensor is calibrated based on the signal from the fluidic oscillation element, that is, the pressure sensor. There is.

[0008]

When the fluidic flowmeter for gas is used as a gas meter, the fluid vibration of the fluidic oscillation element is detected when the pressure of the supply gas changes pulsationally due to a load change. There is a problem that an electric signal that should be originally output from the pressure sensor may be missing or a whisker-shaped signal may be additionally superposed, resulting in an error in the integrated flow rate.

When a "pulse dropout" occurs in which an electric signal is lacking, the integrated flow rate becomes too small, and when a "whisker" occurs, the integrated flow rate becomes excessive and the integrated flow rate becomes too large. Further, if there is a “pulse dropout”, the cycle of the electric signal of the pressure sensor at that time becomes abnormally large, and the sensor is unnecessarily switched from the pressure sensor to the flow sensor. FIG. 9 is a diagram for explaining a state when such a “pulse omission” occurs. As shown in FIG. (A), the pulse P _1, P ₂ ... electric signals of the pressure sensor, of the P _6, P _7, when the pulse P ₄ should come out inherently lacks the pulse P ₃
After a certain period of time, a flow sensor drive signal is output as shown in FIG. 4B, and the sensor is switched from the pressure sensor to the flow sensor.

Since the flow sensor intermittently operates at intervals of several seconds to perform intermittent measurement, when the cycle of the electric signal of the pressure sensor fluctuates due to the fluctuation of the supply pressure, the pressure sensor and the flow sensor are frequently switched. There is a problem that a measurement error occurs.

Therefore, an object of the present invention is to provide a fluidic gas meter which can solve these problems.

[0012]

In order to achieve the above object, a fluidic gas meter according to claim 1 converts fluid vibration of a fluidic oscillator (7) into an electric signal by a pressure sensor (10). In a gas meter that measures a flow rate based on this electric signal, the cycle of the electric signal of the pressure sensor (10) is sequentially compared based on a predetermined threshold coefficient to detect a change tendency, and the change tendency is detected. It is characterized in that "pulse omission" is complemented accordingly.

In this fluidic gas meter, the period of the electric signal of the pressure sensor (10) according to the fluid movement of the fluidic oscillator (7) is successively compared based on a predetermined threshold coefficient. , "Pulse omission" is complemented in accordance with the tendency of the change of the cycle.

A fluidic gas meter according to a second aspect is a gas meter in which fluid vibration of a fluidic oscillator (7) is converted into an electric signal by a pressure sensor (10), and the flow rate is measured based on the electric signal. Characteristic of sequentially comparing the period of the electric signal of the pressure sensor (10) based on a predetermined threshold coefficient to detect a change tendency, and complementing the "whisker" according to the change tendency. Is.

In this fluidic gas meter, the period of the electric signal of the pressure sensor (10) according to the fluid vibration of the fluidic oscillator (7) is successively compared based on a predetermined threshold coefficient. , "Whiskers" are complemented in accordance with the changing tendency of the cycle.

A fluidic gas meter according to a third aspect of the invention is a gas meter in which fluid vibration of a fluidic oscillator (7) is converted into an electric signal by a pressure sensor (10), and the flow rate is measured based on the electric signal. Sequentially comparing the cycle of the electric signal of the pressure sensor (7) based on a predetermined threshold coefficient to detect a change tendency, and complementing "pulse omission" and "beard" according to this change tendency. It is characterized by.

In this fluidic gas meter, the cycle of the electric signal of the pressure sensor (10) corresponding to the fluid vibration of the fluidic oscillator (7) is successively compared based on a predetermined threshold coefficient. , “Pulse dropout” and “beard” are complemented according to the tendency of the change of the cycle.

In the fluidic gas meter according to the fourth aspect, the fluid vibration of the fluidic oscillating element (7) is converted into an electric signal by the pressure sensor (10), and based on the electric signal, the flow rate in the medium to large flow rate range. The gas sensor for measuring the flow rate in the small flow rate range based on the electric signal of the flow sensor (12) arranged in the nozzle (2) of the fluidic oscillation element (7).
0) The period of the electric signal of 0) is sequentially compared based on a predetermined threshold coefficient to grasp the changing tendency, and “pulse omission” and “beard” in the electric signal of the pressure sensor (10) are detected according to the changing tendency. And the pressure sensor (10) and the flow sensor (12) based on the complemented electric signal.
It is characterized by performing switching of.

In this fluidic gas meter, the period of the electric signal of the pressure sensor (10) corresponding to the fluid vibration of the fluidic oscillation element (7) is successively compared based on a predetermined threshold coefficient. , “Pulse dropout” and “beard” are complemented according to the tendency of the change of the cycle.

Then, the pressure sensor (10) and the flow sensor (12) are switched based on the electrical signal thus complemented. The fluidic gas meter according to claim 5 is the fluidic gas meter according to claim 1, wherein when the tendency of the change of the cycle is such that “cycle increase” is followed by “cycle decrease”, “pulse omission” occurs. Is determined, and the large cycle (T _{n + 1} ) is divided into two cycles each having a half of the cycle to be processed.

In this fluidic gas meter, the period of the electric signal of the pressure sensor (10) corresponding to the fluid vibration of the fluidic oscillator (7) is sequentially compared based on a predetermined threshold coefficient. , "Pulse omission" is complemented in accordance with the tendency of the change of the cycle.

Then, when the tendency of the change of the cycle is such that "cycle increase" is followed by "cycle decrease" continuously, it is judged as "pulse missing", and a large cycle (T _{n + 1} ) is 1/2 of that. Is processed in two cycles of size.

A fluidic gas meter according to a sixth aspect of the present invention is the fluidic gas meter according to the second aspect, in which the tendency of change of the cycle is that "cycle decrease" is followed by "cycle increase". When “no cycle increase / decrease” / “cycle increase” appears consecutively in succession after “cycle decrease”, it is judged as “whisker” and two cycles (T _{n + 1} ) (T
_{n + 2} ) are concatenated and processed as one cycle (T _{n + 1} + T _{n + 2} ).

In this fluidic gas meter, the period of the electric signal of the pressure sensor (10) corresponding to the fluid vibration of the fluidic oscillation element (7) is sequentially compared based on a predetermined threshold coefficient. , "Whiskers" are complemented in accordance with the changing tendency of the cycle.

Then, when the change tendency of the cycle is such that "cycle increase" appears consecutively after "cycle decrease", and "no cycle increase / decrease" / "cycle increase" follows in this order after "cycle decrease". When it appears as “beard”, two cycles (T _{n + 1} ) (T _{n + 2} ) are connected to form one cycle (T _{n + 1} +
T _{n + 2} ).

A fluidic gas meter according to a seventh aspect of the present invention is the fluidic gas meter according to the third or fourth aspect, in which the change tendency of the cycle is such that "cycle increase" is followed by "cycle decrease". In some cases "pulse missing"
It is determined that the large cycle (T _{n + 1} ) is divided into two cycles each having a half size of the cycle, and the change tendency of the cycle is “cycle decrease” followed by “cycle increase”. If there are consecutive occurrences and "cycle reduction" followed by "cycle increase / decrease"
When "increase in period" appears consecutively in sequence, it is determined as "whisker", and two periods (T _{n + 1} ) (T _{n + 2} ) are connected to form one period (T _{n + 1} + T). It is characterized by processing as _{n + 2} ).

In this fluidic gas meter, the period of the electric signal of the pressure sensor (10) corresponding to the fluid vibration of the fluidic oscillator (7) is successively compared based on a predetermined threshold coefficient. , “Pulse dropout” and “beard” are complemented according to the tendency of the change of the cycle.

Then, when the tendency of the change of the cycle is "cycle increase" and "cycle decrease" successively, it is judged as "pulse missing", and the large cycle (T _{n + 1} ) is half of that. It is processed in two separate cycles.

When the change tendency of the cycle appears "cycle decrease" followed by "cycle increase", "cycle decrease" followed by "no cycle increase" and "cycle increase" appear in this order. If it is judged as "beard", two cycles (T _{n + 1} )
(T _{n + 2} ) are concatenated and processed as one cycle (T _{n + 1} + T _{n + 2} ).

Further, the pressure sensor (10) and the flow sensor (12) are switched based on the electric signal thus complemented.

[0031]

EXAMPLE In FIG. 2, 1 is an inlet, 2 is a nozzle, and 3,
3'is a side wall, 4, 4'is an inlet of a feedback flow channel, 5 is a target located in the downstream central portion of the nozzle 2, 6 is an outlet, and 7 is an entire fluidic oscillation element composed of inlets 1 to 6 Is. Reference numeral 8 is a case body forming the fluidic oscillator 7.

Reference numeral 10 is a pressure sensor composed of a piezoelectric film sensor, which detects the fluid vibration of the fluidic oscillation element guided by the pressure introduction paths 9 and 9'and converts it into an electric signal.
Reference numeral 12 denotes a thermal type flow sensor arranged in the nozzle 2, which detects a flow velocity that is increased by being narrowed by the nozzle 2 and detects a flow velocity (flow rate).
An analog electric signal proportional to is output every 6 seconds.

Reference numeral 11 is an amplifier for amplifying the electric signal of the pressure sensor 10, and 13 is an A / D conversion circuit for converting the analog electric signal of the flow sensor 12 into electric pulses having a pulse number proportional to the flow velocity (flow rate).

For easy understanding, FIG. 2 shows a state in which the lid of the fluidic oscillator 7 is removed.
The pressure sensor 10 for detecting the fluid vibration includes a pair of pressure introduction ports 14 and 14 'which are opened to the feedback flow paths 4 and 4'.
By connecting one end of each of the pressure introducing passages 9 and 9'to each other and communicating each other end of the pressure introducing passages 9 and 9'to the pair of pressure introducing ports 15 and 15 'of the pressure sensor 10,
Pulsating pressure due to fluid vibration is differentially applied to both sides of the polymer piezoelectric film 16.

The arrow A shows the flow of gas flowing into the inlet 1 of the fluidic oscillator 7. In the block diagram of FIG. 1, a waveform shaping circuit 17 converts the output of the amplifier 11 into a binarized square wave electric signal. Reference numeral 18 denotes a cycle measuring unit, which measures the cycle of the output signal (square wave) of the waveform shaping circuit 17.

Reference numeral 19 is a change tendency determination unit, which is a pressure sensor 10.
Of the electric signal is sequentially compared based on a predetermined threshold coefficient to detect the change tendency. Reference numeral 20 denotes a threshold coefficient memory for storing the threshold coefficient. Reference numeral 21 denotes a pulse complementing unit, which complements “pulse omission” and “beard” in accordance with the change tendency captured by the change tendency determining unit 19.

Reference numeral 22 denotes a sensor switching determination unit, which is based on the electrical signal complemented by the pulse complementation unit 21
And the flow sensor 12 is switched. Reference numeral 23 is a flow sensor drive control circuit, which is a flow sensor switching determination unit 2
When it is determined that 2 is measured by the flow sensor 12, the flow sensor 12 is drive-controlled for 6 seconds at short intervals.

A pulse counter 24 counts the number of output pulses of the A / D conversion circuit 13 every 6 seconds. Reference numeral 25 denotes a first volume conversion unit that multiplies the pulse of the pressure sensor 10 complemented by the pulse complementation unit 21 by a pulse constant to convert it into a volume. A second volume conversion unit 26 converts the count value of the pulse counter 24, that is, the number of pulses of the flow sensor 12 every 6 seconds, into a volume by multiplying the pulse constant.

Reference numeral 27 denotes a changeover switch which is operated by a signal from the sensor changeover judging section 22 to select the output signals of the first volume converting section 25 and the second volume converting section 26 and input them to the integrating section 28.

The integrating unit 28 integrates the outputs of the first and second volume converting units 25 and 26 selected by the changeover switch 27. The gas usage amount thus integrated is displayed as a number on the display unit 29.

When the pressure sensor 10 detects the fluid vibration of the fluidic oscillator 7, the period is determined by the period measuring unit 18.
Is sequentially measured based on the threshold coefficient stored in the threshold coefficient memory 20, and the change tendency determination unit 1
At 9, the change tendency of the cycle is examined, and it is discriminated as one of the following three tendencies.

(1). When the relationship between the cycle T _{n at} that time and the immediately preceding cycle T _n-1 is (3/2) T _n-1 <T _n (1), the change tendency of the cycle is “cycle increase”. judge.

(2). When the relationship between the cycle T _{n at} that time and the cycle T _n-1 immediately before is (2/3) T _n-1 ≤T _n ≤ (3/2) T _n-1 (2), It is determined that the change tendency is “no cycle increase / decrease”.

(3). When the relationship between the cycle T _{n at} that time and the cycle T _n-1 immediately before is (2/3) T _n-1 > T _n (3), the tendency of the cycle change is “cycle decrease”. judge.

In the above equations (1) to (3), (3/2) and (2/3) used for comparison with the period T _n are the threshold coefficients, which are predetermined thresholds. It is stored in the value coefficient memory 20.

Then, when the tendency of the change of the cycle is such that the "cycle increase" is followed by the "cycle decrease" continuously, it is judged that the "pulse omission" has occurred, and the "pulse omission" is complemented. That is, a large cycle is divided into two cycles, that is, a half of the cycle, and processed.

The concept of processing for complementing this "pulse omission" will be described below with reference to FIG. The pressure sensor 10 detects the fluid vibration of the fluidic oscillation element 7 and the cycle of the electrical signal shaped into a square wave by the waveform shaping circuit 17 is the cycle T _n , followed by the cycle T _n , as shown in FIG. _{n + 1} and period T
_Since it is continuous with _{n + 2,} and (3/2) T _n <T _{n + 1} , “period increase” and subsequently T _{n + 1} > (3/2) T _{n + 2.} , "Cycle reduction", it is determined in this case that "pulse omission" has occurred.

FIG. 7B shows a pulse complementing process performed because it is determined that the pulse is missing. The large period T _{n + 1} of FIG. _{n + 1} of 2
The figure shows a state in which the pulse is divided into one cycle and one pulse which is not added in the end is added and complemented.

Next, the concept of "whisker" determination and its complementary processing will be described below with reference to FIG. The pressure sensor 10 detects the fluid vibration of the fluidic oscillating element 7 and the cycle of the electric signal shaped into a square wave by the waveform shaping circuit 17 is a cycle following the cycle T _n , as shown in FIG. Continuing with T _{n + 1} , period T _{n + 2} , and period T _{n + 3} , (2/3) T _n > T _{n + 1} ... “Period reduction” (3/2) T _{n + 1} <T _{n +2} … “Cycle increase” T _{n + 2} = T _{n + 3} … “No cycle increase / decrease”, and there is a tendency of “cycle increase” followed by “cycle increase”, so “beard” occurs. It is determined that the hair is present and the "beard" is complemented.

That is, by connecting two periods of the period T _n and the period T _{n + 1} into one, as shown in FIG.
_The “beard” is complemented by processing as _n + T _{n + 1} .
That is, in this case, only one whisker-shaped electric signal pulse is processed to be canceled, and this processing is expressed as complementing the "whisker" here.

FIG. 5 shows a change tendency of the period of the electric signal which is detected by the pressure sensor 10 of the fluid vibration of the fluidic oscillation element 7 and shaped into a square wave by the waveform shaping circuit 17, which is different from the case of FIG. , Is a diagram for explaining the concept of the process when it is determined to be "beard".

In this case, the cycle of the electric signal is as shown in FIG.
Like the following, the cycle T _n is followed by the cycle T _{n + 1} , the cycle T _{n + 2} , and the cycle T _{n + 3,} and (2/3) T _n > T _{n + 1} ... (2/3) T _{n + 1} ≤ T _{n + 2} ≤ (3/2) T _{n + 1} ... "No cycle increase / decrease" (3/2) T _{n + 2} <T _{n + 3} ... "cycle increase" Therefore, since there is a continuous trend of "no cycle increase / decrease" and "cycle increase" following "decrease cycle", it is judged that "beard" is still occurring, and "beard" Complement.

That is, the two cycles of the cycle T _{n + 1} and the cycle T _{n + 2} in FIG. 11A are processed as one cycle T _{n + 1} + T _{n + 2} as shown in FIG. This complements the "beard". That is, in this case, processing is performed so as to cancel only one whisker-shaped electric pulse, and this processing is expressed as complementing the "whisker" in this case as well.

By the way, as described above, the pressure sensor 10
The tendency of the electrical signal cycle of is grasped, and from this tendency, it is judged whether "pulse missing" or "whisker", and the processing for complementing them is performed. The overall processing procedure also includes the following. .

(A) Initialization process At the time when the first cycle of the pressure sensor 10 is measured, it cannot be compared with the immediately preceding cycle, so the tendency of change from the immediately preceding cycle is uniquely "no cycle increase / decrease". And

Until the next cycle is measured, it is not determined whether the acquired cycle can be used as it is, so it is stored as "pending data". At the same time, the data of the tendency of changing the cycle is also stored.

(B) Sequential processing After the second cycle, the next (b)
-1) and (b-2) are performed.

(B-1) When it is determined to be "pulse missing" or "whisker", the process according to each content is performed, and the latest cycle data is stored as "hold data".

The period data subjected to the "pulse omission" and "whisker" determination processing is transferred to the supplemented data. At this time, the latest data of the change tendency of the cycle is “no cycle increase / decrease”. (B-2) If "pulse missing" and "whisker" are not determined, the "hold data" that is not affected by the next change tendency is transferred to the supplemented data, and the other data is sequentially shifted. Then, it is stored as “holding data”. Similarly, the change tendency data is also shifted and stored. "Pulse missing"
And the change tendency after the “whisker” determination is uniquely defined as “no increase / decrease in cycle” in the above (b-1).
This is because of the reason (d).

(C) In order to avoid self-contradiction of processing, the supplemented data is used for determining the flow rate (cycle) measured by the fluidic oscillator and for volume conversion. It may have been executed for judgment or volume conversion.

If the increase / decrease comparison is performed again with the supplemented cycle without making “no cycle increase / decrease” uniquely, it may be necessary to rewrite data already used for other processing. That is, there is a contradiction that the flow rate determination and volume conversion performed in the past are erroneous.

(D) In order to keep the processing delay to a minimum, in order to prevent the occurrence of the "self-contradiction" in the above-mentioned item (c), the determined cycle of "data after complementation" is directly applied to another processing. It is possible to deal with it by not using it as described above, but by making it retain as "reserved data for the next processing".

However, in that case, a new processing delay is added in addition to the delay until it is determined as the post-completion data. Next, a few specific examples of pulse complementation when gas is supplied to the gas meter of this embodiment will be described.

FIG. 6 shows the waveform of the electric signal when the steady flow is 170 [l / h]. FIG. 6 (a) shows the waveform before the complement and FIG. 6 (b) shows the waveform after the complement. It can be seen that the “pulse missing” in FIG. 9A is complemented and the pulse indicated by the symbol P in FIG.

FIG. 7 shows the steady flow 170 as in the case of FIG.
An electrical signal waveform indicating the "whisker" complementing process at [l / h] is shown in FIG. 9A in which the "beard" indicated by the reference sign P'is present in the waveform before the complementation.

In FIG. 6B, this "beard"P'is gone, and it can be seen that the "beard" complement processing has been performed. FIG. 8 is a waveform of an electric signal when an unsteady flow having a varying flow rate is flown. FIG. 8A shows the waveform before the complement, and FIG. 8B shows the waveform after the complement.

In the illustrated portion, "pulse omission" in FIG. 9A is complemented as shown in FIG. Further, in the part shown in the figure, the “whiskers” in FIG. 11A are complemented as shown in FIG.

[0068]

As described above, the fluidic gas meter of the present invention captures the tendency of the period of the electric signal obtained by converting the fluid vibration of the fluidic oscillation element by the pressure sensor and determines the "pulse" according to the tendency of the change. Since "dropout" and "beard" are complemented, even if "pulse dropout" or "beard", which is a signal lack due to gas pressure fluctuation, occurs, a signal close to the electrical signal that should be output. Supplementation can be achieved, and the occurrence of measurement error of the gas meter can be reduced.

Further, at the flow rate in the vicinity of the switching of the pressure sensor and the flow sensor, the frequent switching of the sensor is suppressed, so that the measurement error of the gas meter can be reduced also from this aspect.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an entire embodiment of the present invention.

[FIG. 3] “Pulse missing” in the gas meter according to the embodiment of the present invention
6A and 6B are diagrams for explaining the concept of processing in the case of complementing, where FIG. 6A is a diagram showing the waveform of an electric signal before being supplemented, and FIG.

4A and 4B are views for explaining the concept of processing when complementing "whiskers" with the gas meter according to the embodiment of the present invention, where (a) is the waveform of the electrical signal before complementing, and (b) is the electrical signal after complementing. It is a diagram showing a waveform of a signal.

5A and 5B are views for explaining the concept of processing when complementing "whiskers" with the gas meter according to the embodiment of the present invention, where (a) is the waveform of the electrical signal before complementing and (b) is the electrical spectrum after complementing. It is a diagram showing a waveform of a signal.

6A and 6B are waveforms of an electric signal when a steady flow is passed through the gas meter according to the embodiment of the present invention. FIG. 6A is a waveform before “pulse missing” is complemented, and FIG. 6B is a waveform after “pulse missing” is complemented. It is a diagram showing a waveform.

7A and 7B are waveforms of an electric signal when a steady flow is passed through the gas meter according to the embodiment of the present invention. FIG. 7A is a waveform before “whisker” complementation, and FIG. 7B is a waveform after “whisker” complementation. It is a diagram showing.

FIG. 8 is a waveform diagram of an electric signal when an unsteady flow is passed through the gas meter of the embodiment of the present invention, in which (a) shows a signal waveform before complementation and (b) shows a signal waveform after complementation. Is.

FIG. 9 (a) shows a waveform of an electric signal obtained by detecting a fluid vibration of a fluidic oscillator according to a conventional technique with a pressure sensor.
The flow sensor drive signal is shown in (b).

[Explanation of symbols]

2 nozzle 7 fluidic oscillator 10 pressure sensor 12 flow sensor _{T n, T n + 1,} T n + 2 periods

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumi Oni 9-10 Fujinosawa City, Kanagawa Prefecture Misonodai (10) (72) Inventor Katsuto Sakai 3-2-7-123 (72) Inventor, Takasago, Katsushika-ku, Tokyo Shinichi Sato 543-15 Kitano-cho, Hachioji-shi, Tokyo (72) Inventor Shigenori Okamura 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Within Osaka Gas Co., Ltd. (72) Takato Sato Tokai-shi, Aichi 507-2, Shinhomachi Toho Gas Co., Ltd. Research Institute of Technology (72) Inventor Masahito Naganuma 1-270, Sennen 1-chome, Atsuta-ku, Nagoya-shi, Aichi (72) Inventor, Iro Hori Nagoya, Aichi Aichi Clock Electric Co., Ltd. 1-270 Chitose, Atsuta-ku, Yokohama-shi

Claims (7)

[Claims] 1. A gas meter for converting fluid vibration of a fluidic oscillating device (7) into an electric signal by a pressure sensor (10) and measuring a flow rate based on the electric signal, the electric signal of the pressure sensor (10). A fluidic gas meter characterized in that the cycle of is sequentially compared based on a predetermined threshold coefficient to detect a change tendency, and "pulse omission" is complemented according to the change tendency. 2. A gas meter for converting a fluid vibration of a fluidic oscillation element (7) into an electric signal by a pressure sensor (10) and measuring a flow rate based on the electric signal, the electric signal of the pressure sensor (10). The fluidic gas meter is characterized in that the cycle of is sequentially compared based on a predetermined threshold coefficient to detect a change tendency, and "whiskers" are complemented according to the change tendency. 3. A gas meter for converting fluid vibration of a fluidic oscillating element (7) into an electric signal by a pressure sensor (10) and measuring a flow rate based on the electric signal, the electric signal of the pressure sensor (7). A fluidic gas meter characterized in that the cycle of is compared sequentially based on a predetermined threshold coefficient to detect a change tendency, and "pulse omission" and "whisker" are complemented according to the change tendency. 4. The fluid vibration of the fluidic oscillation element (7) is converted into an electric signal by the pressure sensor (10), the flow rate in the medium to large flow rate range is measured based on this electrical signal, and the fluidic oscillation element is measured. In the gas meter for measuring the flow rate in the small flow rate range based on the electric signal of the flow sensor (12) arranged in the nozzle (2) of (7), the cycle of the electric signal of the pressure sensor (10) is set in advance. Sequential comparisons are made based on the threshold value coefficient to detect the change tendency, and “pulse omission” and “beard” in the electric signal of the pressure sensor (10) are complemented according to the change tendency, and
A fluidic gas meter, characterized in that the pressure sensor (10) and the flow sensor (12) are switched based on the complemented electric signal. 5. When the change tendency of the cycle is such that “cycle increase” is followed by “cycle decrease” in succession, it is judged as “pulse missing” and a large cycle (T _{n + 1} ) is determined as the first. The fluidic gas meter according to claim 1, wherein the fluidic gas meter is processed by being divided into two cycles having a size of / 2. 6. The case where the tendency of the cycle change is “cycle decrease” followed by “cycle increase” and “cycle decrease”.
If "No increase / decrease in cycle" / "Increase in cycle" appear consecutively in sequence, it is judged as "whisker" and two cycles (T
_{n + 1} ) (T _{n + 2} ) are connected to form one cycle (T _{n + 1} + T
3. The fluidic gas meter according to claim 2, wherein the fluidic gas meter is treated as _{n + 2} ). 7. When the change tendency of the cycle is such that “cycle increase” is followed by “cycle decrease” in succession, it is determined as “pulse missing”, and a large cycle (T _{n + 1} ) is determined as the first. It is divided into two cycles of the size of / 2, and when the change tendency of the cycle continuously appears "cycle decrease" followed by "cycle increase" and "cycle decrease" follows "cycle decrease". If no increase / decrease ”/“ cycle increase ”appear consecutively in order, it is judged as“ whisker ”and two cycles (T _{n + 1} )
5. The fluidic gas meter according to claim 3, wherein (T _{n + 2} ) is connected and processed as one cycle (T _{n + 1} + T _{n + 2} ).