JP2002122457A - Gas cut-off device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas cut-off device for precisely measuring the flow rate zero state in no use of a gas appliance to monitor whether the using quantity and using state of a medium is safe or not. SOLUTION: The flow velocity in the medium is detected by a flow velocity detecting means 14 in no use of the gas appliance, and when the flow rate value determined by flow rate arithmetic means 20 is out of a prescribed range, flow rate stop detecting means 21 drives interrupting means 26 to interrupt a passage 1. The flow rate determined after interruption is stored in flow rate correction value storing means 22 as a flow rate correction value for adjusting the flow rate to zero, and the frequency of storage is measured by correction frequency measuring means 23. The flow rate value determined by the flow rate arithmetic means 20 in the use of the gas appliance is corrected with the flow rate correction value by flow rate correcting means 27. When the frequency measured by the correction frequency measuring means 23 reaches a prescribed number of frequencies, an abnormality is determined by correction determining means 24 and alarmed by alarming means 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the flow velocity of various media flowing in a pipe, for example, LP gas, using ultrasonic waves or the like, and accurately measuring the amount of the medium used. The present invention relates to a gas shut-off device that monitors whether a state is safe.

[0002]

2. Description of the Related Art A conventional gas shut-off device of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-21667. FIG. 2 shows a block diagram of a conventional gas shut-off device.

In FIG. 2, reference numeral 1 denotes a flow path, and reference numeral 2 denotes a first vibrator. The first vibrator transmits and receives ultrasonic waves and is installed on the upstream side of the flow path 1. 3
Is a second vibrator, which transmits and receives ultrasonic waves, and is attached to the downstream side of the flow path 1 so as to be opposed. Reference numeral 4 denotes a transmission circuit, which transmits an ultrasonic signal to the first transducer 2, and reference numeral 5 denotes an amplification circuit, which amplifies a signal received by the second transducer 3. A comparison circuit 6 compares the amplified signal with a reference signal. 7 is a timing means,
The time from transmission to reception of the ultrasonic wave is measured by a timer counter. Reference numeral 8 denotes a measuring circuit, which includes the transmitting circuit 4 to the time measuring means 7. Numeral 9 denotes a flow rate calculating means for obtaining a flow rate value in consideration of the size of the pipeline and the state of the flow according to the ultrasonic wave propagation time by the time measuring means 7. Reference numeral 10 denotes a cycle variable means, and a flow rate calculating means 9
The measurement cycle is changed based on the flow rate value obtained in step. 11
Is a measurement start unit that adjusts a signal transmission timing to the transmission circuit according to the value of the cycle variable unit 10. Numeral 12 denotes a measurement end means for detecting the end of the operation of the flow rate operation means 9. 13
Is a voltage control means for reducing the voltage of the measurement circuit 8 in synchronization with the measurement ending means 12 and for restoring the voltage of the measurement circuit 8 in synchronization with the start of measurement by the measurement start means 11.

Next, the operation of the conventional configuration will be described. In the flow path 1 through which a medium (gas) such as city gas and LP gas flows, a burst signal is transmitted from the transmission circuit 4 by the measurement start means 11, and the ultrasonic signal transmitted by the first vibrator 2 is transmitted through the flow path 1. , And received by the second oscillator 3, further subjected to signal processing by the amplifier circuit 5 and the comparison circuit 6, and the time from transmission to reception is measured by the timer 7. When the flow rate is large, it is necessary to increase the time sampling and reduce the error. When the flow rate is small or when the flow rate is zero, even if the measurement sampling is slowed down, almost no error occurs. Therefore, the measurement interval is changed according to the value of the flow rate calculating means 9.
When the value of the flow rate calculation means 9 is small, the interval of the measurement time is increased by the cycle variable means 10, and as the value of the flow rate calculation means 9 increases, the measurement time interval is reduced. Further, the voltage of the measurement circuit 8 is reduced between measurements. When the flow rate measurement is completed by the flow rate calculation means 9, the measurement end means 12
The voltage is lowered by the voltage control means 13 or
Set to zero. Then, before the start of the flow velocity measurement, the voltage of the measurement circuit 8 is restored by the voltage control means 13.

[0005]

However, in the above-mentioned conventional configuration, the measuring circuit 8 is installed after the gas shut-off device is installed.
The flow rate value when the gas appliance is not used, that is, the flow rate is zero or deviates from a predetermined flow rate range (this range is defined as zero flow rate) due to the temporal change of the first vibrator 2 or the second vibrator 3 is detected. There is no disclosure of a method for detecting a state in which the number of abnormal deviations from the predetermined flow rate range is greater than that in a predetermined flow rate range. For this reason, there is a problem that the flow rate is erroneously accumulated when the gas appliance is used thereafter, so that accurate flow rate measurement for monitoring the gas use state cannot be performed.

Therefore, the present invention solves the above-mentioned problems, and accurately measures the zero flow rate when no gas gas or LP gas is used after the gas shut-off device is installed, that is, when the gas appliance is not used. An object of the present invention is to provide a gas shut-off device that measures an accurate usage amount to monitor a usage state and notifies a gas company of an abnormality when a flow correction when a gas appliance is not used is abnormal. Is what you do.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, after a gas shut-off device is installed, a flow rate value obtained by a flow rate calculating means from a flow rate detected by a flow rate detecting means when a gas appliance is not used is determined as a flow rate. When the flow rate stop detecting means detects that the flow rate is outside the predetermined flow rate range deviated from zero, the flow path is cut off by the cutoff means, and the flow rate value of the flow rate calculating means obtained from the flow rate of the used gas medium after the cutoff is set to zero. The flow rate correction value for adjustment is stored in the flow rate correction value storage means and the number of times stored is measured by the correction number measurement means, and the flow rate value obtained when the gas user uses the gas appliance is calculated by the flow rate correction means. The correction is performed with the flow rate correction value, and when the number of times measured by the number-of-times-of-correction measurement means reaches a predetermined value, it is determined that the correction determination means is abnormal and the notification means notifies the abnormality.

Thus, the gas flow rate when the gas appliance is not used, that is, the zero flow state, is accurately measured after the gas shut-off device is installed, and it is prevented that the gas appliance is used incorrectly and the flow rate accumulation is continued. By doing so, it is possible to accurately measure the usage amount for monitoring the usage state of the gas, and to issue a warning such as a notification of replacement when the number of times of obtaining the flow rate correction value becomes abnormally large, indicating that the gas is becoming abnormal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to achieve the above object, the present invention provides a flow rate detecting means for measuring a signal propagation time in a medium to detect a flow rate, and a flow rate for obtaining a flow rate value from the flow rate detected by the flow rate detecting means. Calculating means for detecting a flow stop when the flow rate value obtained by the flow rate calculating means is within a predetermined range and outputting a cutoff signal when the flow rate value is out of the predetermined range when the gas appliance is not used; Means, a blocking means for blocking the medium flow path, and a flow rate correction value storage for storing a flow rate value obtained by the flow rate calculating means in a state where the flow rate closing means closes the flow path by the flow rate stop detecting means as a flow rate correction value. Means, a correction number measuring means for measuring the number of times stored as the flow correction value, a flow correction means for correcting the flow value obtained by the flow calculating means with the flow correction value when using the gas appliance, and the correction number Number measured by the measuring means, characterized in that a notifying means for informing at decision and determining correction determination means that an abnormality reaches a predetermined value, an abnormality in the correction determination means.

According to the present invention, the flow stop detecting means detects the flow velocity by the flow detecting means when the gas appliance is not used, and detects the flow stop when the flow value obtained by the flow calculating means is within a predetermined range. If the flow rate value is outside the predetermined range, the flow path is closed by the blocking means, and in the blocked state, the flow rate value obtained by the flow rate calculating means is stored as a flow rate correction value in the flow rate correction value storage means, and the stored number is stored. It is measured by the correction frequency measuring means. When the gas appliance is used, the flow rate value calculated by the flow rate calculation means is corrected by the flow rate correction means using the flow rate correction value. Therefore, when the gas appliance is not used, the flow rate is always zero or within a predetermined flow rate range (assuming the flow rate is zero). Measurement can be performed, and it is possible to prevent the accumulation of the flow rate when the gas appliance is not used by mistake. Also, it is determined whether the number of times measured by the number-of-corrections measuring means by the correction determining means, that is, the number of times the flow rate correction value is obtained, is abnormally large. , And in the worst case, an abnormality such as replacement of the gas shut-off device. Therefore, the gas usage can always be integrated and monitored by an accurate gas shutoff device, and the user's gas usage can be monitored by accurate flow measurement, thereby improving reliability and safety.

[0011]

An embodiment of the present invention will be described below with reference to FIG. 1, components having the same functions as those in FIG. 2 are denoted by the same reference numerals.

FIG. 1 shows a gas measuring apparatus according to an embodiment of the present invention. Numeral 14 is a flow velocity detecting means, which transmits an ultrasonic signal from one side to the other side between the upstream side vibrator 2 and the downstream side vibrator 3 which are installed opposite to the flow path 1 of a gas medium such as city gas or LPG,
The flow velocity of the used gas is detected from the propagation time. A indicates the direction in which the gas medium flows.

The flow velocity detecting means 14 comprises, as an example, a switching means 15, a transmitting means 16, a receiving means 17, a repeating means 18, and a propagation time measuring means 19, as shown in FIG. Has adopted. Transmission means 16 and reception means 1
7 is connected to the switching means 15, the switching means 15 first connects the transmitting means 16 to the upstream vibrator 2, the receiving means 17 to the downstream vibrator 3, and then connects the transmitting means 16 to the downstream vibrator 3.
Then, the connection destination of the transmission means 16 and the reception means 17 is alternately switched such that the reception means 17 is connected to the upstream transducer 2. The repetition means 18 is provided with the receiving means 17 for the upstream vibrator 2 and the transmitting means 16 for the downstream vibrator 3 by the switching means 15.
Are connected, the ultrasonic signal transmitted from the transmission means 16 is received by the reception means 17 from the downstream transducer 3 via the flow path 1 from the upstream transducer 2. In this way, the transmission from the transmission of the ultrasonic signal to the reception is repeated, and the operation of measuring the propagation time of the ultrasonic signal by the propagation time measuring means 19 is repeated. The propagation time measuring means 19 measures and accumulates the time from transmission to reception of the ultrasonic signal. Next, the receiving means 17 is connected to the downstream vibrator 3 and the transmitting means 16 is connected to the upstream vibrator 2 by the switching means 15, and the above operation is repeated. The propagation time measuring means 19 obtains a propagation time difference from the propagation time measured first and the propagation time measured after switching by the switching means 15 next.

Numeral 20 denotes a flow rate calculating means, a detected flow velocity value,
That is, the amount of the medium used, that is, the gas flow rate is converted from the propagation time to obtain the amount. Reference numeral 21 denotes a flow stop detecting means which determines whether or not the flow value obtained by the flow calculating means 20 is within a predetermined flow range (for example, ± 1.5 L / h) when the gas appliance is not used. It is determined that the flow is stopped, and if the flow is out of the predetermined flow range, it is determined that the flow rate zero offset is generated, and the shutoff means 26 described later is driven. Numeral 22 is a flow rate correction value storage means, which stores the flow rate value detected by the flow rate detecting means 14 and obtained by the flow rate calculating means 20 as an offset correction value after the flow rate stop detecting means 21 determines that a flow rate zero offset has occurred. Numeral 23 is a correction frequency measuring means for obtaining a zero flow rate offset amount, and counting the number of times when the amount is stored. Numeral 24 is a correction judging means for judging whether or not the number counted by the correction number measuring means 23 has reached a predetermined number. Reference numeral 25 denotes an abnormality determining unit which determines whether or not the gas is used abnormally based on the flow rate corrected by the flow rate correcting unit 27 based on the gas usage calculated by the flow rate calculating unit 20. For example, when the hose that supplies gas to the equipment used such as a stove comes off for some reason, the total flow cutoff value to monitor the abnormal large flow that occurs,
A usage time cut-off table or the like which defines a usage time limit corresponding to a case where the appliance is used much longer than the normal maximum usage time is stored, and it is monitored whether there is any abnormality corresponding thereto. Reference numeral 26 denotes a shut-off unit, which outputs a shut-off signal when the flow stop detecting unit 21 detects a flow offset, that is, a flow outside a predetermined range.
When it is determined in step 5 that the corrected flow rate is abnormal, a shutoff signal is output to shut off the gas flow path 1. Numeral 27 is a flow rate correcting means. The flow rate value obtained by the flow rate calculating means 20 from the flow rate detected by the flow rate detecting means 14 with the flow path 1 closed by the shut-off means 26 is a flow rate correction value when the flow rate is zero, that is, a flow rate offset correction. The flow rate is stored in the flow rate correction value storage means 22 as a quantity, and then the flow rate value obtained when the gas appliance is used is corrected with the flow rate correction value.
Numeral 28 is a notifying means. When the number of corrections measuring means 23 counts and the correction judging means 24 judges that the number of times of the offset correction is abnormal, the gas interrupting device maintenance warning is notified and the abnormality judging means 25 judges that the gas use state is abnormal. If it is determined that the shut-off means 26 is driven, the shut-off state and the contents of the shut-off are displayed on a liquid crystal display element or the like, and the center for safety monitoring of gas is notified via a telephone line.

Next, the operation of the above configuration will be described. When the gas shutoff device is installed and the gas appliance is not used, the flow rate value calculated by the flow rate calculating means 20 from the flow rate detected by the flow rate detecting means 14 is zero or within a predetermined range (for example, less than ± 1.5 L / h). Based on the output of the flow rate calculating means 20, the flow rate stop detecting means 21 initially stores the state of zero flow rate. The flow rate correction value is measured in advance so that the flow rate becomes zero, and stored in the flow rate correction value storage means 22 so that the flow rate becomes zero or within a predetermined flow rate range. When the gas appliance is used, the flow rate value obtained by the flow rate calculation means 20 is used as the flow rate. The correction is performed using the correction value, the integration is performed using the corrected flow rate, and the corrected flow rate is monitored to determine whether or not there is an abnormal use. Here, when the gas appliance is not used, for example, the used flow rate is registered when the gas appliance is used by the flow rate calculating means 20, but when the gas appliance is not registered at all, it is determined that the gas appliance is not used. However, due to various environmental conditions, temperature, humidity, etc., the flow value when the gas appliance is not used does not fall to zero or within a predetermined range as the device is used over a long period of time. In some cases, the flow rate may be deviated from the zero flow rate state or the flow rate correction value that is determined to deviate from the predetermined flow rate range. That is, the flow rate stop detecting means 21 determines that a flow rate offset has occurred when it detects that the flow rate value when the gas appliance is not used is within the predetermined flow rate range, but falls outside the predetermined flow rate range. Therefore, a new flow rate correction value is obtained by the following method and adjusted so as to be within a predetermined flow rate range.

In a state in which the gas appliance is not used, the flow velocity is detected by the flow velocity detecting means 14 installed in the flow path 1 and converted into a flow rate value by the flow rate calculating means 20, and the flow rate detecting means 21 is a flow rate value within a predetermined flow rate range. When a flow value deviating from a predetermined range is detected even though the stop is detected, it is determined that the flow has deviated from the zero flow state, and a shutoff signal is output from the flow stop detecting means 21 to the shutoff means 26, and the flow path 1 Cut off. In the cutoff state, the flow velocity is detected by the flow velocity detecting means 14, a flow signal deviating from the zero flow state is obtained from the flow calculating means 20, and the flow enters a new flow correction value measuring state. Since the flow path 1 is closed by the shutoff means 26, the flow rate correction value is measured in a state where no instrument is used and there is no flow rate. Here, the operation of an example of the flow velocity detecting means 14 will be described.

In a flow path (gas pipe) 1, an ultrasonic signal is transmitted and received between an obliquely installed upstream vibrator 2 and a downstream vibrator 3. The switching means 15 causes the upstream vibrator 2
Is connected to the downstream vibrator 3 while being connected to the receiving means 17, and receives a signal transmitted from the transmitting means 16 from the upstream vibrator 2 via the downstream vibrator 3.
This operation is performed the number of times set by the repetition means 18. A so-called sing-around system is configured. The propagation time until the receiving means 17 receives the ultrasonic signal transmitted from the transmitting means 16 is accumulated, and the time is obtained by the propagation time measuring means 19.

Next, the switching means 15 connects the transmitting means 16 to the downstream vibrator 3 and the receiving means 17 to the upstream vibrator 2. The ultrasonic signal output from the transmitting means 16 is received by the receiving means 17 connected to the upstream transducer 2 via the flow path 1 via the downstream transducer 3. This operation is performed the number of times set by the repetition means 18. Transmission means 1
The propagation time until the ultrasonic signal transmitted from 6 is received by the receiving means 17 is accumulated and obtained by the propagation time measuring means 19,
Further, a propagation time difference is obtained from a propagation time when the ultrasonic signal is transmitted from the upstream to the downstream and a propagation time when the ultrasonic signal is transmitted from the downstream to the upstream. The flow rate calculating means 20 is the propagation time measuring means 1
9 is converted into a flow velocity value, and then the flow velocity calculating means 20 converts the flow velocity value into a flow velocity value.

The calculated flow rate value should be zero due to environmental factors such as temperature, although the propagation time difference should be zero when the equipment is not used and should be zero as a result, or should be within a predetermined flow rate range. . Then, the flow rate deviates from the original zero flow rate or a predetermined flow rate range. The flow stop detecting means 21 determines that an offset has occurred when detecting that the flow has not returned from a state where the flow has been zero or within a predetermined flow range.

Therefore, the flow stop detecting means 21 obtains the flow velocity by the flow velocity detecting means 14 while driving the shut-off means 26 and closes the flow path 1, and converts the flow velocity into the flow value by the flow calculating means 20.
This flow rate value is set as a new flow rate correction value and the flow rate correction value storage means 2
Stored in 2. At the same time, the number of times the flow rate correction value is obtained is counted by the correction number measurement unit 23. On the other hand, blocking means 2
When the gas appliance 6 is driven to open the flow path 1 and the gas appliance can be used as usual, the flow rate correction means 27 detects the flow rate by the flow rate detection means 14 and converts the flow rate value converted by the flow rate calculation means 20 into the flow rate correction value storage means 22. Is corrected with the new flow rate correction value stored in (the sign of the correction value is ±, there is addition correction or subtraction correction),
Find the true flow rate. As a result, the flow rate value when the appliance is not used is zero flow rate or within a predetermined flow rate range (defined as zero flow rate range).
And the flow rate can be measured accurately even when the instrument is used. However, as the time elapses, the flow rate zero value shifts due to environmental conditions such as temperature and humidity, and the flow rate correction value becomes unsuitable. At this time, the flow rate correction value is obtained again and stored in the flow rate correction value storage means 22, and each time the correction number measuring means 23 counts the number. Some gas shut-off devices are increasingly required to determine the flow rate correction value with respect to environmental conditions. The state is monitored by the correction determination means 24. In other words, the deterioration with the lapse of time such that the flow rate deviates abnormally from zero occurs, and the number of times of obtaining the flow rate correction value increases abnormally. The means 24 notifies the notification means 28 of the maintenance warning. The gas company can perform maintenance such as replacing the gas shut-off device by looking at the contents.
In addition, it can be determined whether or not the gas shut-off device always measures the flow normally.

Therefore, it is possible to prevent the flow rate error from being accumulated and accumulated erroneously while the flow rate zero offset occurs many times and the new flow rate correction value is obtained again. Therefore, when the gas appliance is not used, the small flow rate detected as shifted is incorrectly added to the gas usage as if the appliance is used, and the chance that a warning is displayed incorrectly if the gas is leaking is reduced,
In a state where the flow rate measurement accuracy is extremely high, it is possible to always monitor the usage meter reading of the gas customer and whether there is any abnormal use, and it is possible to suppress unnecessary dispatch of the gas company, thereby improving reliability, safety and usability.

In this way, after the gas shut-off device is installed, a flow rate correction value is determined so as to automatically adjust the flow rate to a zero state.
The original flow rate can be set to zero, and the frequency of obtaining the correction value is monitored by the correction frequency measuring means 23, and the correction determining means 24 determines whether or not it is abnormal. Can determine whether the offset is likely to be offset and notify the gas company.
The gas company can perform maintenance at an early stage, and in the worst case, take measures such as replacing the gas shut-off device. Therefore, there is no problem such as erroneously determining an abnormal large flow rate by monitoring the usage status of gas appliances and shutting off the total flow rate, or erroneous meter reading due to a flow rate offset and accumulating accumulation errors even when the flow rate is stopped. The usage status of gas can be monitored.

[0023]

As described above, according to the present invention, a flow rate detecting means for measuring a signal propagation time in a medium to detect a flow rate, and a flow rate calculation for obtaining a flow rate value from the flow rate detected by the flow rate detecting means. Means for detecting a flow stop when the flow rate value calculated by the flow rate calculation means is within a predetermined range and outputting a cutoff signal when the flow rate value is out of the predetermined range when the gas appliance is not used. Blocking means for blocking the medium flow path; and flow rate correction value storage means for storing a flow rate value obtained by the flow rate calculation means in the state where the flow rate closing means closes the flow path by the flow rate stop detection means as a flow rate correction value. When,
Correction frequency measurement means for measuring the number of times stored as the flow rate correction value, and flow rate correction means for correcting the flow rate value obtained by the flow rate calculation means with the flow rate correction value when using a gas appliance,
A correction judging means for judging an abnormality when the number of times measured by the number-of-corrections measuring means reaches a predetermined value, and a notifying means for notifying the abnormality when the correction judging means judges that there is an abnormality. When the instrument is not in use, the flow rate is detected by the flow rate detecting means and the flow rate value obtained by the flow rate calculating means is within a predetermined range, and the flow stop is detected if the flow rate value is out of the predetermined range. In the closed and shut-off state, the flow rate value obtained by the flow rate calculation means is stored in the flow rate correction value storage means as a flow rate correction value, and the number of times stored is measured by the correction number measurement means. When the gas appliance is used, the flow rate value calculated by the flow rate calculation means is corrected by the flow rate correction means using the flow rate correction value. Therefore, when the gas appliance is not used, the flow rate is always zero or within a predetermined flow rate range (assuming the flow rate is zero). Measurement can be performed, and it is possible to prevent the accumulation of the flow rate when the gas appliance is not used by mistake. Also, it is determined whether the number of times measured by the number-of-corrections measuring means by the correction determining means, that is, the number of times the flow rate correction value is obtained, is abnormally large. , And in the worst case, an abnormality such as replacement of the gas shut-off device. Therefore, it is always possible to accumulate and monitor gas consumption with an accurate gas shut-off device,
Since the gas usage status of the user can be monitored by accurate flow measurement, reliability and safety are improved.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a gas cutoff device according to an embodiment of the present invention.

FIG. 2 is a control block diagram of a conventional gas shut-off device.

[Explanation of symbols]

 14 Flow velocity detecting means 20 Flow rate calculating means 21 Flow rate stop detecting means 22 Flow rate correction value storage means 23 Correction frequency measuring means 24 Correction determining means 26 Cutoff means 27 Flow rate correcting means 28 Notification means

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Norio Niimura 1006 Kadoma Kadoma, Osaka Pref.Matsushita Electric Industrial Co., Ltd. (72) Inventor Isao Masuda 23 Minamikashima, Futama-machi, Tenryu-shi, Shizuoka Prefecture Inside Yazaki Keiki Co., Ltd. Norihiro Harada 23rd Minamikashima, Futamata-cho, Tenryu-shi, Shizuoka F-term (reference) 2F030 CA03 CC13 CD11 CF05 CF11 2F035 DA16 3J071 AA03 BB11 BB14 CC11 EE02 EE07 EE16 EE18 EE26 EE31 EE37 FF03

Claims (1)

[Claims] 1. A flow rate detecting means for measuring a signal propagation time in a medium to detect a flow rate, a flow rate calculating means for obtaining a flow rate value from a flow rate detected by the flow rate detecting means, Flow stop detection means for detecting a flow stop when the flow value obtained by the arithmetic means is within a predetermined range and outputting a cutoff signal when the flow value is outside the predetermined range,
Blocking means for blocking the medium flow path, flow rate correction value storage means for storing the flow rate value obtained by the flow rate calculation means in the state where the flow closing means the flow path closed by the flow rate stop detection means, as a flow rate correction value, Correction number measurement means for measuring the number of times stored as the flow rate correction value, flow rate correction means for correcting the flow rate value obtained by the flow rate calculation means with the flow rate correction value when the gas appliance is used, and measurement by the correction number measurement means A gas shut-off device comprising: a correction judging means for judging an abnormality when the number of times it has reached a predetermined value; and a notifying means for notifying when the correction judging means judges an abnormality.