JP4141825B2 - Flowmeter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flow meter such as a gas meter or a water meter, which is used mainly for business purposes, and can determine the reverse connection and use it properly even if it is connected in reverse to the original connection direction. .
[0002]
[Prior art]
Conventionally, in a gas meter used for business purposes, a gas back flow in the gas meter is detected, and safety measures such as blocking are performed. (For example, see Patent Document 1)
FIG. 6 shows a configuration example of a gas meter conventionally used for business use.
[0003]
As shown in FIG. 6, the gas meter 1 includes a controller 2, a flow sensor 3, an external sensor 4, a shutoff valve 5, and a display unit 6, and is further connected to a communication device 7.
[0004]
The controller 2 includes a flow rate calculation unit 21, a security unit 24, and a usage amount integration unit 25, and processes signals from the flow rate sensor 3 and the external sensor 4. The flow sensor 3 sends a signal corresponding to the gas flow direction and flow rate to the controller 2. Examples of the external sensor 4 include a seismic device that detects an earthquake and a pressure sensor that measures a pressure value, and signals from these sensors are input to the controller 2. The shut-off valve 5 is attached to the upstream side or the downstream side of the flow sensor 3 and has a function of stopping the gas supply by a signal from the controller 2. The display unit 6 receives a signal such as an integrated flow value from the controller 2 and displays it. The communication device 7 has a function of reading various information of the gas meter 1.
[0005]
The flow rate calculation means 21 in the controller 2 periodically determines the direction of gas flow from a signal according to the gas flow direction and flow rate acquired from the flow rate sensor 3, and if the gas is flowing in the forward direction, the flow rate is determined. A flow rate with a positive sign added to the absolute value (hereinafter referred to as “positive flow rate”), and when flowing in the opposite direction, a flow rate with a negative sign added to the absolute value of the flow rate (hereinafter “negative flow rate”) ").
[0006]
The security unit 24 monitors whether there is an abnormal use of the gas from the flow rate calculated by the flow rate calculation unit 21 and monitors whether there is an abnormality such as an earthquake or a pressure drop according to the state of the external sensor 4. When an abnormal use of gas or an abnormality such as an earthquake or a pressure drop is detected, the shutoff valve 5 is closed to stop the gas supply, and a display showing the type of the abnormality that has occurred is displayed on the display unit 6. The communication device 7 is notified of the occurrence of an abnormality.
[0007]
The usage amount integrating unit 25 integrates the gas usage amount from the flow rate calculated by the flow rate calculating unit 21 and displays the integrated gas usage amount on the display unit 25. Further, the accumulated gas use amount can be read from the communication device 7.
[0008]
FIG. 7 is a flow chart of the flow rate processing in the prior art.
[0009]
The flow rate process is performed at a constant cycle. First, a flow rate signal corresponding to the gas flow direction and flow rate is acquired from the flow rate sensor 3 (ST61). Next, it is determined whether or not the gas flow direction is the forward direction (ST62). When the gas flow direction is the forward direction, a positive flow rate is calculated (ST63), and when the gas flow direction is the reverse direction, a negative flow rate is calculated (ST64), and the gas usage is integrated based on the value (ST64). ST65). When the integrated amount becomes less than a certain negative value in the integration of the gas usage amount, it is determined that the gas meter is connected in reverse, and the gas shutoff is performed by closing the shutoff valve 5 as a security process (ST66).
[0010]
[Patent Document 1]
JP 2001-296161 A (page 2-5, FIG. 5)
[0011]
[Problems to be solved by the invention]
As described above, in the prior art, the gas flow direction is the reverse direction from the signal acquired from the flow sensor 3, and the integrated value of the amount of gas used is less than a certain value (below a certain negative value. Gas is reversed. In the case of flowing in the direction, when the accumulated amount of use becomes a negative value), it was determined that the gas meter was connected in reverse, and the shut-off valve 5 was closed. For this reason, when it was determined that the gas meter was connected in reverse, the gas could not be used normally unless the gas meter was correctly connected thereafter. In addition, when a gas meter that has been correctly connected is changed in connection for some reason, the connection change time cannot be specified.
[0012]
The present invention has been made in view of such problems, and determines the connection status when a flow meter such as a gas meter or a water meter, which is mainly used for business, is connected in the opposite direction to the normal connection direction. If it is determined that the connection is reverse, the flow rate sign is reversed so that the correct flow measurement can be continued without changing the connection even in the reverse connection state, or the integrated value at the time when the reverse connection is changed. Or it aims at provision of the flow meter which specifies the time.
[0013]
[Means for Solving the Problems]
A flow meter according to the present invention is a flow meter that is connected to a fluid pipe to be measured, passes the fluid to be measured from one connection port to the other connection port, and measures the flow direction and flow rate of the fluid, When the fluid to be measured flows in the flow meter in a predetermined direction, the flow rate is calculated by adding a positive sign to the absolute value of the flow rate, and the fluid to be measured is reversed in the flow meter in the predetermined direction. The flow rate calculating means for calculating a flow rate with a negative sign added to the absolute value of the flow rate, and the fluid to be measured is flowing in the flow meter in a direction opposite to the predetermined direction. Is a reverse connection determination unit that determines that the flow meter is connected in reverse, and when the reverse connection determination unit determines that the flow meter is reverse connected, the flow rate calculated by the flow rate calculation unit and a flow rate code switching means for switching a positive or negative sign, is the reverse connection determination means When it is determined that the flow meter is reversely connected, the flow rate integration unit that integrates the flow rate by the flow rate after the sign of the flow rate is switched by the flow rate code switching unit, and the reverse connection determination unit include the flow meter Storage means for storing at least one of the integrated flow rate and the determination time when it is determined that the connection is reverse .
[0014]
As described above, according to the flowmeter of the present invention, when the flowmeter is connected in the reverse direction to the normal connection direction, it is determined that the flowmeter is reversely connected and the flow rate code is reversed. However, correct flow measurement can be continued without changing the connection. Furthermore, when it is determined that the flow meter is connected in the reverse direction of the normal connection direction, the flow rate integrated amount and the determination time at the time of determining the reverse connection are stored, and therefore the flow meter for some reason. When the connection change is made, an appropriate charge can be made for the use of the fluid to be measured, and a penalty can be imposed for the gas use after the time of reverse connection.
[0015]
The flow meter according to the present invention is a flow meter that is connected to a fluid pipe to be measured, allows the fluid to be measured to pass from one connection port to the other connection port, and measures the flow direction and flow rate of the fluid. When the fluid to be measured flows in the flow meter in a predetermined direction, a flow rate obtained by adding a positive sign to the absolute value of the flow rate is calculated, and the fluid to be measured flows in the flow meter in a predetermined direction. The flow rate calculating means for calculating the flow rate with a negative sign added to the absolute value of the flow rate, the flow rate integrating means for integrating the flow rate calculated by the flow rate calculating means, and the measured When the fluid flows in the flow meter in a direction opposite to the predetermined direction, reverse connection determination means for determining that the flow meter is connected in reverse, and the reverse connection determination means include the flow meter Is determined to be reverse connection, the flow rate at the time of determining reverse connection Characterized in that it comprises a storage means for storing at least one of the calculated amount and the determination time.
[0016]
As described above, according to the flow meter of the present invention, when it is determined that the flow meter is connected in the opposite direction to the normal connection direction, both the integrated flow rate and the determination time at the time when the reverse connection is determined. Alternatively, since either one is stored, when the flow meter connection is changed for some reason, it is possible to charge appropriately for the use of the fluid to be measured.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a flow meter according to the present invention will be described in detail with reference to FIGS. 1 to 5. In addition, the same code | symbol is attached | subjected to the same structure as the conventional structure shown in FIG. 6, and detailed description is abbreviate | omitted.
[0018]
FIG. 1 is a configuration diagram of a flow meter according to the first embodiment of the present invention.
[0019]
In the first embodiment, a flow meter according to the present invention is applied as a gas meter for measuring the amount of gas used by a consumer for business purposes, using the fluid to be measured as gas.
[0020]
In the present embodiment, the gas meter 1 includes a controller 2, a flow sensor 3, an external sensor 4, a shutoff valve 5, and a display unit 6, and the controller 2 is further connected to a communication device 7.
[0021]
The controller 2 includes a flow rate calculation unit 21, a reverse connection determination unit 22, a flow rate code switching unit 23, a security unit 24, a usage amount integration unit 25, and a storage unit 26, and signals from the flow rate sensor 3 and the external sensor 4. Process.
[0022]
The flow sensor 3 sends a signal corresponding to the gas flow direction and flow rate to the controller 2. Examples of the external sensor 4 include a seismic device that detects an earthquake and a pressure sensor that measures a pressure value, and signals from these sensors are input to the controller 2.
[0023]
The shut-off valve 5 is attached to the upstream side or the downstream side of the flow sensor 3 and has a function of stopping the gas supply by a signal from the controller 2. The display unit 6 receives a signal such as an integrated flow value from the controller 2 and displays it. The communication device 7 reads various information of the controller 2 and performs various settings for the controller 2 and cancellation of the settings.
[0024]
FIG. 2 is a diagram illustrating the gas flow direction in the present embodiment.
[0025]
As shown in FIG. 2, when a gas meter is normally connected in a gas supply pipe 8 for supplying gas from a gas supply source to a consumer, that is, the gas supply pipe 8 is connected to the connection port of the gas meter 1. When gas is supplied to the consumer from the connection port 11B by connecting to 11A, the gas as the fluid to be measured flows through the flow path 11 in the gas meter from the connection port 11A via the flow rate sensor 3 to the connection port 11B. Flow in the direction. The gas flow direction in this case is referred to as the forward direction.
[0026]
On the other hand, when the gas meter is connected reversely to the normal in the gas supply pipe, that is, when the gas meter is reversely connected, the gas supply pipe 8 is connected to the connection port 11B of the gas meter 1, and the gas is connected to the connection port. It is in a state of being supplied to the consumer from 11A. In such a case, the gas as the fluid to be measured flows through the flow path 11 in the gas meter from the connection port 11B to the connection port 11A via the flow sensor 3. The gas flow direction in this case is referred to as the reverse direction. The flow sensor 3 sends a signal corresponding to the gas flow direction and flow rate to the controller.
[0027]
As shown in FIG. 1, the flow rate calculation means 21 in the controller 2 determines the direction of gas flow from the gas flow direction obtained from the flow rate sensor 3 and a signal corresponding to the flow rate, and the gas flows in the forward direction. The flow rate is calculated by adding a positive sign to the absolute value of the flow rate (hereinafter referred to as “positive flow rate”). "Negative flow rate") is calculated.
[0028]
The reverse connection determination means 22 determines whether or not the gas meter 1 is reversely connected from the flow rate calculated by the flow rate calculation means and the gas flow direction. In this case, even when the gas meter 1 is connected in the gas supply pipe as usual, when a pulsation of the gas flow occurs due to a gas pressure fluctuation or the like, the gas flows in the reverse direction (hereinafter referred to as a reverse flow). Sometimes). Therefore, in the determination of the reverse connection, it is necessary to distinguish whether the reverse flow has occurred due to pulsation or whether the reverse flow has occurred because the gas meter 1 is connected in reverse.
[0029]
Therefore, the reverse connection determination means 22 pays attention to the fact that the reverse flow generated when the consumer uses gas in the reverse connected state continues for a longer time than the reverse flow generated by pulsation. In this way, reverse connection is determined. That is, the flow rate calculated by the flow rate calculation means 21 is integrated (hereinafter referred to as an integrated flow rate), and the integration time is measured. Then, every time the integration time reaches a predetermined time (for example, 600 seconds), the integrated flow rate is compared with a predetermined value (for example, -5 liters, the flow rate is negative when backflowing), When the integrated flow rate is equal to or less than a predetermined value, it is determined that the connection is reversed.
[0030]
Here, as a method for determining the reverse connection, the integrated flow rate is compared with the predetermined value every time the integration time reaches a predetermined time. The number of times of integration is counted, and the integrated flow rate is compared with a predetermined value every time the number of integration times reaches the predetermined number. Alternatively, it may be determined that the connection is reverse. Or it is good also as determining with reverse connection, when a flow volume value becomes below a predetermined value continuously for a predetermined period. Furthermore, it is good also as determining with reverse connection, when the state that the flow volume is below a predetermined value every time integration is performed is continuously generated a predetermined number of times. Further, the predetermined time, the predetermined number of times of integration, the predetermined value of the integrated flow rate, and the predetermined value of the flow rate can be set from the communication device 7.
[0031]
The flow rate code switching unit 23 outputs the flow rate calculated by the flow rate calculation unit 21 when the reverse connection determination unit 22 determines that the gas meter is normally connected, and calculates the flow rate when it is determined to be reverse connection. The flow rate output by the means 21 is switched between positive and negative (that is, the flow rate is negative when the sign is positive and positive when the sign is negative). Here, since the gas meter 1 is used to measure the amount of gas used by the consumer, the flow rate output by the flow rate code switching means 23 means the amount of gas used by the consumer.
[0032]
The security means 24 monitors whether there is an abnormal use of the gas from the flow rate output from the flow rate code switching means 23, that is, the gas usage amount at the consumer. For example, when the gas usage amount becomes excessive, the safety valve 24 The gas supply is stopped, the gas supply is stopped, a display indicating “excess gas use” is displayed on the display unit 6, and the occurrence of “excess gas use” is reported to the communication device 7. In addition, the external sensor status is monitored for abnormalities such as earthquakes and pressure drops, and when abnormal use of gas or abnormalities such as earthquakes or pressure drops are detected, the shutoff valve is closed and gas supply is stopped. The display indicating the type of abnormality that has occurred is performed on the display unit, and the occurrence of the abnormality is reported to the communication device 7. Further, when the reverse connection determination means 22 determines that the connection is reverse, the shutoff valve is closed to stop the gas supply, a display indicating the reverse connection is displayed on the display unit, and the occurrence of the reverse connection is indicated to the communication device 7. It is also possible to report. At this time, the communication device 7 can thereafter cancel the reverse connection determination. Further, when the communication device 7 determines that the reverse connection determination means 22 is reverse connection, the communication device 7 displays the reverse connection on the display unit 6 without stopping the gas supply, and the communication device generates the reverse connection. 7 can also be selected to report.
[0033]
The usage amount integrating unit 25 integrates the gas usage amount from the flow rate output by the flow rate code switching unit 23 and displays the integrated gas usage amount on the display unit. Further, the integrated gas use amount can be read from the communication device 7.
[0034]
When the reverse connection determination unit 22 determines that the reverse connection is established, the storage unit 26 stores the integrated value of the gas usage at the time when the reverse connection is determined and the time when the reverse connection is determined. Further, the integrated value and time of the gas usage stored in the storage means 26 can be read from the communication device 7.
[0035]
FIG. 3 is a flow chart of flow rate processing in the present embodiment.
[0036]
As shown in FIG. 3, first, the flow rate calculation means 21 acquires a flow rate signal from the flow rate sensor (ST11). Next, it is determined whether or not the gas is flowing in the forward direction. If the gas is flowing in the forward direction, a flow rate (positive flow rate) obtained by adding a positive sign to the absolute value of the flow rate is calculated (ST13), and vice versa. If it is flowing in the direction, a flow rate (negative flow rate) is calculated by adding a negative sign to the absolute value of the flow rate (ST14).
[0037]
Subsequently, the reverse connection is determined based on the positive flow rate and the negative flow rate (ST15, ST16). When it is determined that the reverse connection state is established, the flow rate is switched between positive and negative, that is, when the sign of the flow rate is positive. If the sign is negative, it is positive (ST17), and the amount of gas used is integrated (ST18). On the other hand, if it is determined that the reverse connection state is not established, the gas usage is integrated based on the positive flow rate and the negative flow rate as they are (ST16, ST18). The reverse connection determination flow will be described later.
[0038]
Next, it is monitored whether there is an abnormal use of the gas based on the flow rate obtained by the above processing, and for example, when the gas flow rate becomes excessive, the shutoff valve 5 is closed and the gas supply is stopped. (ST19).
[0039]
Next, reverse connection determination will be described with reference to FIG.
[0040]
FIG. 4 is a reverse connection determination flowchart.
[0041]
The reverse connection determination process is performed periodically. As shown in FIG. 4, first, the calculated positive flow rate and negative flow rate are read, and the flow rate is integrated by adding the currently read numerical value to the previous integrated flow rate (ST31). Next, after the accumulated flow rate is cleared to zero, the accumulated time from the start of reverse connection determination processing to the present is measured (ST32). In addition, since the integration of the flow rate in the reverse connection determination is performed in a certain cycle, instead of measuring the integration time, measure the number of integrations up to the present after starting the reverse connection determination process after clearing the integrated flow to zero. Also good.
[0042]
Subsequently, after the integrated flow rate is cleared to zero, it is determined whether or not a predetermined time (for example, 600 seconds) has elapsed since the start of reverse connection determination processing (ST33). If the predetermined time has not elapsed, the reverse connection determination process ends. If the predetermined time has elapsed, it is determined whether or not the integrated flow rate is equal to or less than a predetermined value (for example, -5 liters) (ST34). The determined time and the integrated value of the gas usage at that time are stored (ST36). In ST36, the time determined to be reverse connection and the integrated value of the gas usage at that time are stored, but either the time or the integrated value of the gas usage may be stored.
[0043]
If the integrated flow rate is not less than or equal to the predetermined value, the integrated flow rate is cleared to zero (ST34, ST37), and the reverse connection determination process ends. If the number of integrations is measured in ST32, it is determined in ST33 whether or not the number of integrations exceeds a predetermined number (for example, 600 times), but the subsequent processing flow is the same.
[0044]
As described above, according to the first embodiment, when the gas meter 1 is connected in reverse to the normal connection direction, it is determined as reverse connection, and the flow rate code is reversed. However, correct flow measurement can be continued without changing the connection.
[0045]
In other words, when the gas meter 1 is reversely connected and the function of inverting the flow rate sign is not provided, a negative flow rate is calculated. Since the integrated value of the gas does not increase, the gas charge is not properly charged. Similarly, even if there is an abnormal use of gas, such as an excessive amount of gas used, it cannot be detected, so that gas shutoff and alarm are not performed properly, and there is a risk of being used unsafely.
[0046]
In the present embodiment, when the gas meter 1 is reversely connected, the flow rate sign is reversed, so that the amount of gas used can be integrated or the gas used without changing the connection state of the gas meter 1 in the reverse connection state. A gas shut-off and warning when the amount becomes excessive will be performed appropriately.
[0047]
Further, when the gas meter 1 is determined to be reversely connected, the storage means 26 stores the integrated value of the gas usage and the determination time when the gas meter 1 is determined to be reversely connected, so that, for example, the consumer intentionally reversely connects the gas meter. Even when the operation is performed, it is possible to charge appropriately for the use of gas, or to impose a penalty on the use of gas after the time of reverse connection.
[0048]
Furthermore, when it is determined that the gas meter 1 is reversely connected, the security means 24 can also stop the gas supply by closing the shut-off valve 5, forcing the consumer to stop using the gas. You can also
[0049]
Moreover, since it is determined as reverse connection and the gas supply is forcibly stopped for the consumer, the determination of reverse connection can be canceled from the communication device 7, and then the gas meter is connected in the normal direction. If the reverse connection determination is canceled after confirming that the correction has been made, the gas can be supplied.
[0050]
Further, since the reverse connection determination means 22 determines reverse connection when the flow rate integrated within a predetermined time or the predetermined number of integrations is equal to or less than a predetermined value, even when a reverse flow occurs due to pulsation of the gas flow, Reverse connection can be determined.
[0051]
Further, since the predetermined value of the integrated flow rate, the predetermined value of the flow rate, the predetermined time, and the predetermined number of integration times required for the reverse connection determination can be set from the communication device 7, the set value can be easily set according to the pulsation occurrence state. Can be changed.
[0052]
In the first embodiment, when the reverse connection is determined, the flow rate code switching means 23 inverts the flow rate code, but an embodiment that does not include the flow rate code switching means 23 is also possible.
[0053]
Below, 2nd Embodiment except the flow volume code | symbol switching means 23 which switches the positive / negative of a flow volume from 1st Embodiment is described. In the second embodiment, the configuration of the flow meter 1 and the function of each component are the same as those in the first embodiment except for the flow rate code switching means 23 (see FIG. 1).
[0054]
FIG. 5 is a flow chart of flow rate processing according to the second embodiment. As shown in FIG. 5, first, the flow rate calculation means 21 acquires a flow rate signal from the flow rate sensor (ST21). Then, it is determined whether the gas is flowing in the forward direction (ST22), calculates the gas gave a positive sign to the absolute value of the flow rate when flowing in the forward direction flow (positive flow) (ST23 ) If the flow is in the opposite direction, the flow rate (negative flow rate) is calculated by adding a negative sign to the absolute value of the flow rate (ST24).
[0055]
Subsequently, reverse connection is determined based on the positive flow rate and the negative flow rate (ST25), and the accumulation of gas usage is continued (ST26).
[0056]
Since the reverse connection determination flow is the same as in the first embodiment, the time determined to be reverse connection and the integrated value of the gas usage at that time are stored (see FIG. 4).
[0057]
As described above, according to the second embodiment, when the gas meter 1 is determined to be reversely connected, the integrated value of gas use and the determination time when the storage means 26 is determined to be reversely connected are stored. For example, even if the customer intentionally reversely connects the gas meter, it is possible to charge appropriately for the use of gas or to penalize the gas use after the time of reverse connection .
[0058]
The above describes the embodiment when the present invention is applied to a gas meter. However, the scope of the present invention is not limited to a gas meter, but is applied to all flow meters mainly used for trading, such as a water meter. Needless to say, this is applicable.
[0059]
【The invention's effect】
When a flow meter used mainly for trading, such as a gas meter or water meter, is connected in the opposite direction to the normal connection direction, it is determined as reverse connection and the flow rate code is reversed. The correct flow rate measurement can be continued without changing the connection, and the integration of the flow rate and the interruption and alarm when the flow rate becomes excessive can be appropriately performed.
[0060]
In addition, since the integrated flow rate at the time when the connection is changed to the reverse connection or the time point is specified, for example, even when the customer intentionally reversely connects the flow meter, the appropriate charge is charged for the use be able to.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a flow meter according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram of a gas flow direction. FIG. 3 is a flow rate processing flowchart in the first embodiment. FIG. 4 is a reverse connection determination flowchart.
FIG. 5 is a flow chart of flow rate processing in a second embodiment. FIG. 6 is a configuration diagram of a conventional gas meter.
FIG. 7 is a conventional flow rate processing flowchart.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas meter 2 Controller 3 Flow sensor 4 External sensor 5 Shut-off valve 6 Display part 7 Communication apparatus 21 Flow rate calculation means 22 Reverse connection determination means 23 Flow rate code switching means 24 Safety means 25 Flow rate integration means 26 Storage means

Claims (9)

A flowmeter connected to a fluid pipe to be measured, passing the fluid to be measured from one connection port to the other connection port, and measuring the flow direction and flow rate of the fluid,
When the fluid to be measured flows in the flow meter in a predetermined direction, a flow rate obtained by adding a positive sign to the absolute value of the flow rate is calculated, and the fluid to be measured has a predetermined direction in the flow meter. When flowing in the reverse direction, flow rate calculation means for calculating a flow rate with a negative sign added to the absolute value of the flow rate,
When the fluid to be measured flows in the flow meter in a direction opposite to the predetermined direction, reverse connection determination means for determining that the flow meter is connected in reverse,
When the reverse connection determination means determines that the flowmeter is reversely connected, a flow rate code switching means for switching between positive and negative signs of the flow rate calculated by the flow rate calculation means,
When the reverse connection determination means determines that the flowmeter is reversely connected, the flow rate integration means for integrating the flow rate by the flow rate after switching the sign of the flow rate by the flow rate code switching unit,
When the reverse connection determination means determines that the flow meter is reverse connection, a storage means for storing at least one of an integrated flow rate and a determination time at the time of determining reverse connection ;
A flow meter comprising: A flowmeter connected to a fluid pipe to be measured, passing the fluid to be measured from one connection port to the other connection port, and measuring the flow direction and flow rate of the fluid,
When the fluid to be measured flows in the flow meter in a predetermined direction, a flow rate obtained by adding a positive sign to the absolute value of the flow rate is calculated, and the fluid to be measured has a predetermined direction in the flow meter. When flowing in the reverse direction, flow rate calculating means for calculating a flow rate with a negative sign added to the absolute value of the flow rate,
Flow rate integration means for integrating the flow rate calculated by the flow rate calculation means;
When the fluid to be measured flows in the flow meter in a direction opposite to the predetermined direction, reverse connection determination means for determining that the flow meter is connected in reverse,
When the reverse connection determination means determines that the flow meter is reverse connection, a storage means for storing at least one of an integrated flow rate and a determination time at the time of determining reverse connection;
A flow meter comprising: When the reverse connection determining means determines that the flowmeter is reversely connected, when the flow rate after switching the sign of the flow rate by the flow rate code switching means exceeds a predetermined value, The flow meter according to claim 1, further comprising a security unit that performs blocking. A blocking means for blocking the fluid to be measured when the reverse connection determination means determines that the flowmeter is reversely connected;
Alarm means for giving an alarm when the reverse connection determination means determines that the flowmeter is reversely connected;
A selection means for selecting either the shut-off means or the alarm means by an external signal;
The flow meter according to any one of claims 1 to 3 , further comprising: The flowmeter according to any one of claims 1 to 4 , further comprising reverse connection determination cancellation means for canceling the reverse connection determination performed by the reverse connection determination means. The reverse connection determination means of claim 1 to claim 5, characterized in that determining a reverse connecting the flow meter when the integrated flow rate of the fluid to be measured becomes a negative than a predetermined value in a predetermined time period The flow meter according to any one of the above items. The reverse connection determination means of claim 1 to claim 5, characterized in that determining a reverse connecting the flow meter when the integrated flow rate of the fluid to be measured becomes a negative than a predetermined value in a predetermined number of integration The flow meter according to any one of the above items. The reverse connection determination means determines that the flow meter is reversely connected when the flow rate of the fluid to be measured flowing in the reverse direction becomes a negative predetermined value or less continuously for a predetermined time or continuously for a predetermined number of integrations. The flow meter according to any one of claims 1 to 5 , wherein The predetermined time used as a condition for reverse connection determination by the reverse connection determination means, the predetermined number of times of integration, the predetermined value of the integrated flow rate, and the predetermined value of the flow rate can be set from the outside. The flow meter according to any one of claims 6 to 8 , wherein the flow meter is characterized.

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