JPH0493739A - Minute-gas-leakage detecting apparatus - Google Patents

Abstract

PURPOSE:To make it possible to detect minute gas leakage automatically under the normal gas-using state by detecting and counting the pressures exceeding a preset value. CONSTITUTION:When gas does not leak from a gas pipe 3 and the gas is not used, the pressure in the pipe 3 is increased by the rise of outer temperature. When the minute amount of the gas is leaking, the pressure in the pipe 3 is kept at an approximately constant value regardless of the change in outer temperature. The pressure is not increased to the value higher than a preset value. Then, a pressure detecting means 21b is provided for the gas pipe 3 so as to detect the pressure which is higher than the preset value. When a gas-flow-rate detecting means 22 detects the fact that there is no gas flow rate continuously for a sepcified time period, a counting means 20 counts the detections of the pressures exceeding the preset value. When the result is less than the preset value for the predetermined period, it is judged that the minute amount of the gas is leaking. Then, the minute gas leakage can be automatically detected under the normal gas-using state without stopping the gas feeding for a long time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a micro gas leakage detection device, and in particular, it regulates the pressure of high-pressure gas such as liquefied propane gas contained in an LP gas cylinder to a predetermined pressure. The present invention relates to a minute gas leak detection device for detecting minute gas leaks from a gas supply system that supplies pressure-regulated gas to a terminal gas combustor.

[Conventional technology]

Generally, a propane gas supply system is constructed as shown in FIG. In the figure, high-pressure gas such as liquefied propane gas contained in an LP gas cylinder 1 is regulated to a predetermined pressure by a pressure regulator 2, and this regulated gas is installed in the middle of a gas pipe 3. The gas passes through the gas meter 4 and reaches a gas cock 5, and by opening the gas cock 5, the gas is supplied to the gas combustor 6. Further, the amount of gas consumed by the gas combustor 6 is detected by measuring the amount of gas flowing through the gas pipe 3 with a gas meter 4.

In the gas supply system as described above, cracks may appear in the gas pipe 3 itself leading from the pressure regulator 2 to the gas combustor 6, or corrosion may occur at the joints of the gas pipe 3, resulting in damage from the gas pipe 3. When a minute gas leak occurs, the leaked minute gas may stagnate locally, and this stagnant gas may ignite some kind of fire, resulting in a major explosion.

Therefore, in order to prevent accidents caused by such minute gas leaks, periodic inspections are performed to detect the presence or absence of minute gas leaks. However, in the case of this inspection, the inspector cuts off the gas supply for a long time and monitors the pressure drop in the gas piping during that time.
There is an inconvenience that gas cannot be used during this time, and there is also the problem that a dedicated inspector is required.

Moreover, in the case of this regular inspection, the inspection period is 2
Since it is a relatively long period of one year, if 52 gas leaks occur during that period, nothing can be done, which poses a problem in terms of reliability.

Therefore, the applicant of the present application first set up a gas cutoff valve installed on the upstream side of the gas piping 3, for example, on the inlet side of the pressure regulator 2, when the gas flow rate of the gas piping 3 falls below the predetermined opening amount for a predetermined time. The signal Q from the pressure switch is used to monitor whether the gas pressure in the gas pipe 3 drops below a predetermined pressure for a predetermined period of time in the shut-off state, and the presence or absence of a minute gas leak from the gas pipe 3 is determined based on the result of this monitoring. For example, Japanese Patent Application No. 1-83934 proposes a method for automatically determining the following.

[Problem to be solved by the invention]

However, in the proposed micro gas leak detection, it is assumed that when there is no gas flow for a certain period of time, such as when gas is not used for a long time, such as late at night, gas will not be used after that. Inspections are conducted with the gas shutoff valve shut off.

In addition to finding a time when the gas is not being used, it is also necessary to stop the gas supply, and since the gas cutoff time is long, it is necessary to use one gas exceptionally during that time. When this occurs, there are problems such as the need to manually open the gas cutoff valve.

Therefore, in view of the above-mentioned conventional problems, the present invention provides a micro gas leak that can automatically detect a micro gas leak under normal gas usage conditions without cutting off the gas supply for a long time using a gas cutoff valve. The objective is to provide a detection device.

[Means for Solving the Problems] In order to solve the above problems, the minute gas leakage detection device made according to the present invention is provided in the gas supply path 3, as shown in the basic configuration diagram of FIG. pressure detection means 21b for detecting a pressure equal to or higher than the set pressure; and the pressure detection means 2.
It is equipped with a counting means 20C (!:) that performs counting in response to the detection of pressure equal to or higher than the set pressure by 1b, and when the count value of the counting means 20c within a predetermined period is less than or equal to the predetermined count value, a minute gas leakage is detected. It is characterized by the fact that it is determined that the

In addition, a minute gas leak detection device made according to the present invention in order to solve the problem described in F: Well, as shown in the basic configuration diagram in Fig. 1, a gas supply path 3 is provided, and a preset pressure is set. A pressure detecting means 21b for detecting the above pressure, a gas flow detecting means 22 for detecting that there is no gas flow in the waste supply path 3 continuously for a predetermined time, and the gas flow detecting means 22
a counting means 20c that performs counting in response to detection of a pressure equal to or higher than the set pressure by the pressure detection means 21b when it is detected that there is no gas flow rate for a predetermined period of time, It is characterized in that it is determined that a small amount of gas is leaking when the count value of the counting means 20c is less than a predetermined count value.

(Function) In the above configuration, when there is no minute gas leak, the pressure in the gas supply path is always equal to or higher than the preset pressure due to a rise in outside air temperature, and when there is no minute gas leak, the pressure within the gas supply path is always equal to or higher than the set pressure. Focusing on the point that there is no problem, the counting means 20C performs counting in response to the detection of pressure equal to or higher than the preset pressure by the pressure detection means 21b provided in the gas supply path 3, and the counting means 20C performs counting in response to the detection of the pressure equal to or higher than the preset pressure by the pressure detection means 21b provided in the gas supply path 3. When the count value of the counting means 20c at the counter is less than or equal to a predetermined count value, it can be determined that a small amount of gas is leaking.

Therefore, it is not necessary to cut off the gas supply for a long time using a gas cutoff valve, and it is possible to automatically detect minute gas leaks under normal gas usage conditions.

In addition, when the pressure detection means 21b provided in the gas supply path 3 detects a pressure equal to or higher than a preset pressure, the counting means 20c calculates the count by the gas flow rate detection means 22 when there is no gas flow for a predetermined period of time. This is done on the condition that the pressure detection means 21b is detected.
It is now possible to use it as a means to detect other pressures.

〔Example〕

Examples of the present invention will be described below with reference to the drawings.
Before entering into the description of the embodiments, the principle of detecting minute gas leaks according to the present invention will be explained based on FIGS. 2 and 3.

In the case where there is no slight gas leakage in the gas supply system Q described above with reference to FIG. It will be clearly different.

By the way, the outside air temperature changes throughout the day as shown by the dotted line in Figure 2, with a pattern in which the temperature rises with sunrise, reaches its peak around 3 to 4 o'clock after Q, and then gradually decreases. The gas pipe 3 is exposed to such outside temperature. When there is no leakage in the gas pipe 3 and the pressure regulator is closed due to no gas being used, the pressure inside the gas pipe changes depending on the outside temperature, and when the temperature is high, the pressure increases more than when it is low. do. The pressure rise at the maximum temperature and at the minimum temperature changes as shown in Figure 3 depending on the size of the gas leak, and when the gas leaks above a certain level, the pressure rises even if the outside temperature changes. In addition, due to the characteristics of the pressure regulator, the pressure will not drop drastically when there is a slight leakage.

Therefore, if there is no leakage and the outside temperature is high, after the waste is no longer used and the pressure regulator is closed, the pressure in the gas pipe 3 will decrease to the pressure set value (pressure (higher than the closing pressure of the regulator), and when the outside temperature is low, the pressure will not rise above the set pressure even under the same conditions.

On the other hand, before and after the point where gas leakage is slight, excluding the period when gas is used (during the period, the pressure inside the gas pipe 3 is kept at an approximately constant value regardless of changes in the outside air temperature). , the pressure will not rise above the pressure set value.

Therefore, in the present invention, when there is no minute gas leak, the pressure inside the gas pipe becomes higher than the closing pressure of the pressure regulator for a predetermined period, and when there is a minute gas leak, the pressure inside the gas pipe becomes higher than the closing pressure. Focusing on the fact that it will not become a problem, we are trying to roast out the minute scum (iJ + i l).

The 41st embodiment shows an embodiment of the minute gas leakage detection device according to the present invention, which is configured to detect minute gas leaks based on the above-mentioned principle 22, and the device is incorporated into an electronic gas meter. No. 4752, 11: It is an electronic gas meter connected in the middle of the gas pipe 3, and gas regulated by a gas pressure regulator (not shown) is placed at the inlet, and measured from the outlet. Gas is delivered. The electronic gas meter 11 has a built-in diaphragm measuring section (not shown) that measures the amount of gas sent out from the outlet, is mechanically connected to this measuring section, and is driven by the measuring operation of the measuring section. A measurement display section 11a is provided on the surface thereof. In addition, the internal components of the electronic gas meter 1 include a metering signal generating section that generates a metering signal at each predetermined gas flow rate according to the metering operation of the metering section, a pressure cusp inch that operates at various set pressures, and a metering signal generating section. A signal processing unit that processes signals from the pressure switch and performs various signal processing is provided. Further, on the surface of the electronic gas meter 11, a display section 11b and an alarm section 11 are provided for displaying the result of signal processing by the signal processing section and issuing an alarm.
c. Reset to re-center the processing results of the signal processing unit.
There is also a port operation lid, etc.

FIG. 5 is a block diagram showing the relationship between a signal processing section provided inside the electronic gas meter and a pressure switch connected thereto. In the fifth article, the signal processing unit 20 was composed of a microcomputer (CPU) that operated according to a predetermined control program, and the signal processing unit 20 stored predetermined data in addition to the control program. ROM20 which is read-only memory
a, and a RAM 20b which is a memory that can be continuously written to and used as a work area for signal processing. This signal processing section 20 includes an electronic gas meter 1.
four pressure switches 21a to 21d that turn on or off when the pressure within the meter reaches a preset pressure; flow rate switch 2
2. Display section 11b that displays the result of signal processing by signal processing section 11, alarm section 11c that issues an alarm, and signal processing section 11
Resets for resenting the processing results.

The port operation lid, etc. are connected.

The pressure switches 21a to 21d are provided at any position within the electronic gas meter 11, but are preferably
By removably connecting a pipe containing these pressure switches to the inlet pipe of the electronic gas meter 11, the pressure switch can be installed in a replaceable manner.

The above-mentioned pressure switch 21a is for detecting an increase in the adjusted pressure in which the detection pressure can be set at one point within the range of 450 to 330 mmHzO, and the pressure switch 21b is for detecting an increase in the adjusted pressure.
50mm 1 (for occlusion pressure detection where the detection pressure can be set at the no point within the range of zO, pressure cass inch 2
1c is 255~] The pressure switch 21d is for adjusting pressure drop detection where the detection pressure can be set at one point within the range of 90mmHzO, and the pressure switch 21d is the one for detecting pressure drop that can be set at one point within the range of 50~OmmH2O. This is for detecting an increase in the adjusted pressure.

The flow rate switch 22 is turned on every time a predetermined amount of gas flows through the electronic gas meter 11, and signal processing *Bo; monitors whether the flow rate switch 22 is turned on and detects that a predetermined amount of gas has flowed.

In the RAM2 Ob, as shown in FIG. 6, there are three counters Xl to χ3, two flags F,
, F2, and areas for seven timers T to T7 are set. Timer T measures 30 minutes after the start, timer T4 measures 2 minutes after the start, timer T measures 18 minutes after the start, and timers T2 and T3
, T6 and T7 are for measuring time for 7 days after the clearing.

In the above configuration, the CPU of the signal processing unit 20 executes the work shown in the flowchart of FIG. 7 according to its control program, and in addition to detecting minute gas leaks by detecting pressure drop when gas is not used, it also detects minute gas leaks when gas is used. By detecting a pressure drop, we can detect an abnormality in the adjustment pressure of the force regulator, and the pressure when using gas! By detecting d, a positive blockage abnormality of the pressure regulator is detected, and a pressure increase when gas is not used is detected S: Therefore, an abnormality of the regulated pressure of the pressure regulator is detected.

The CPU of the signal processing unit 20 starts operation when the power is turned on, and in the first step Sl,
Counters X to X4, flags F1 and F2, and timers T to T7 formed in 0b are cleared and set to the initial state. The process then proceeds to step S2, where it is determined whether there is a gas flow rate. The determination in step S2 is made based on whether the gas flow rate is 21ffi or more per hour by reading the status of the switch 22, which is carried out periodically.

When the determination in step S2 is YES, that is, when there is a gas flow rate, the process proceeds to step S3, where timers T4 and T5 and flags F and F2 are cleared, and then the process proceeds to step S4, where the set pressure is 255 to 190 mmL.
Adjustment pressure drop detection pressure cass inch 2 set between O
It is determined whether or not 1c is on, and when it is on, it is determined that the gas pressure in the gas pipe is below the set pressure, and the process proceeds to step S5. In step S5, it is determined whether or not the pressure switch 21d for detecting a decrease in the adjustment pressure rod, whose set pressure is set between 50 and Q mmH2O, is on, and when it is off, the gas pressure in the gas pipe is If it is determined that the pressure is above the set pressure, the process proceeds to step S6, and when it is turned on, it is determined that the gas pressure in the gas pipe is below the set pressure, and the process proceeds to step S13, which will be described later.

In step S6, the timer T is cleared, and the process proceeds to step S7, where the counter X is incremented (+
1) Do. Thereafter, the process advances to step S8, where it is determined whether or not the timer T2 has timed out, that is, whether seven days have elapsed.If the determination at step S8 is NO, the process advances to step S9. In step S9, it is determined whether the content of the counter X1 is 10 or more, and if the determination is NO, the process returns to step S2. The above step,
If the determination in step S8 is YES, that is, if seven days have passed without the determination in step S9 being YES, the process advances to step S10↓, where the counter XI and timer T2 are cleared, and then the process returns to step S2. Also,
When the determination in step S9 is YES, the counter Xl
When the content of ! is 10 or more, the process advances to step Sll and causes the display section 11b to display an alarm, and the alarm section 11c! V
This will generate an alarm sound. Thereafter, the process proceeds to step S12, where it is determined whether or not the reset switch 11d has been operated. Step Sll and step S12 are repeated until the determination becomes YES, and when the determination becomes YES, the process returns to step S1.

Further, when the determination in step S5 is YES, that is, when the pressure switch 21d for detecting a drop in the adjusted pressure set between 50 and Q mmH2O is turned on, the gas pressure in the gas pipe is set to the set pressure. It is determined that the timer T1 is equal to or lower than that, and the process proceeds to step S13, where the timer T1 is started, and the process proceeds to step S14, where it is determined whether or not the timer T1 has timed out, that is, whether 30 minutes have elapsed.

If the determination in step S14 is NO, the process proceeds to step S 75, where Q counter X,
Increment. Judgment in step 314 is YES
, that is, the pressure switch 2 for detecting a decrease in the adjusted pressure
When 1d has been on continuously for 30 minutes, the process advances to step knob S15 to display an alarm on the display section 11b and cause the alarm section 11c to generate an alarm sound. After that, the process proceeds to step 516, where it is determined whether or not the reset switch lid has been operated, and steps S15 and S16 are repeated until this determination becomes YES, and the determination is YES.
When it becomes S, the process returns to step S1.

By executing steps S4 to S16 described above, it is detected whether or not a state where the pressure is lower than the set pressure set between 50 and OmmH2O has occurred for a long period of time (more than 30 minutes) during 7 days, and if detected, Displays/alarms that the adjusted pressure of the pressure regulator is abnormal. In addition, within 7 days, if the pressure is below the set pressure between 255 and 190 mmH2O, or temporary (30 minutes or less) 10 or more times, the adjustment pressure of the pressure regulator is detected. is abnormal and displays/alarms to that effect.

When the determination in step S4 is NO, that is, when the pressure switch 21c for detecting a decrease in the adjusted pressure whose set pressure is set between 255 and 190 mmHzO is turned off, the gas pressure in the gas pipe is equal to or higher than this set pressure. It is determined that this is the case, and the process proceeds to step S17 to clear the timer T1. After that, the process advances to step 818 and the set pressure is 450-33.
It is determined whether or not the pressure switch 21d for detecting an increase in the adjusted pressure set between 0mmtlzOO is on, and when it is off, it is determined that the gas pressure in the gas pipe is below this set pressure, and the step S2 is performed. Go back to , and the judgment is Y.
When the ES is turned on, it is determined that the gas pressure in the gas pipe is equal to or higher than the set pressure, and the process proceeds to step S19, where the counter S2 is incremented (4-1). Step S
After executing Step 19, the process proceeds to step S21, where it is determined whether or not the timer T3 has timed out, that is, whether 7 days have elapsed.
If o, the process advances to step 322. In step 322, it is determined whether the content of the counter X2 is 10 or more, and if the determination is NO, the process returns to step S2. When the determination in step S21 is YES, that is, when seven days have passed without the determination in step S22 being YES, the process proceeds to step S23, where the counter X2 and timer T3 are cleared, and then the step S
Return to 2.

Further, when the determination in step S22 is YES and the content of the counter
c to generate an alarm sound. Thereafter, the process proceeds to step S25, where it is determined whether or not the reset switch 11d has been operated. Steps S24 and S25 are repeated until the determination becomes YES, and when the determination becomes YES, the process returns to step S1.

By executing steps S1B to S25 described above, 7
Detects whether or not a condition exceeding the set pressure set between 450 and 330 mm LOO has occurred 10 or more times during gas use during the day. If detected, the adjusted pressure of the pressure regulator will be displayed as an abnormal increase.・Send a warning.

When the above step S2 is NO, that is, when there is no gas flow rate, the process proceeds to step S30, where the timer T is cleared, and then the process proceeds to step S31.

In step 31, the timer T4 is started, and the process proceeds to step S32, where the timer T4 measures two minutes from its start and determines whether or not the time is over. When the determination in step S32 is No, the process returns to step S2, and when the determination in step S32 is YES, the process advances to step S33. In step S33, timer T is activated.

After starting the timer T, proceed to step S34 and start the timer T.
It is determined whether 18 minutes have elapsed since the start. The determination at step 334 is N.

If the determination is YES, the process proceeds to step S35, and if the determination is YES, the process proceeds to step S45, which will be described later.

In step S35, it is determined whether the flag F is 1 or not, and the determination in step S is N.

If so, the process advances to step S36, and if the determination is YES, the process returns to step S2. In step 53652, flag F1 is set to 1, and then step S3
Proceed to step 8, where it is determined whether the pressure switch 21b for detecting occlusion pressure whose set pressure is set between 450 and 350 mmHzO is on, and when the determination is YES and it is on, the gas piping is It is determined that the gas pressure within is equal to or higher than the set pressure, and the process proceeds to step 539i, and when the determination is NO and is off, the process returns to step S2.

In step S39, the counter X3 is incremented (+1), and then the process proceeds to step 40, where it is determined whether or not the timer T6 has timed out, that is, whether 7 days have elapsed. If so, the process advances to step S41. In step S41, it is determined whether the content of the counter X3 is 100 or more, and if the determination is NO, the process returns to step S2.

When the determination in step S40 is YES, that is, step 7. If seven days have passed without the determination in step S41 being YES, the process advances to step S425, where the counter X3 and timer T6 are cleared, and then the process returns to step S2. Also, the determination in step S41 is YES.
In other words, when the content of the counter X3 is 100 or more, the process advances to step knob S43 to display an alarm on the display section 11b and cause the alarm section 11c to generate an alarm sound.

After that, the process advances to step S44 and the reset switch lid is
Determine whether or not the operation has been performed, and this determination is YES.
Steps 343 and S44 are repeated until the determination becomes YES, and the process returns to step S1.

By executing steps S34 to S44 described above, 7
During the day, it is detected whether or not a state where the pressure is higher than the set pressure between 450 and 350 mmH2O occurs more than 100 times when the gas is not used, and if it is detected, the blockage pressure of the pressure regulator is deemed to have increased abnormally and a notification is issued. Display/alarm.

Further, when the determination in step S34 is YES, that is, after the 2-minute timer T4 has timed out, the 18-minute timer T
, too, and if there is no gas flow for a total of 20 minutes, the process advances to step S45. In step S45, it is determined whether or not flag F2 is 1. If the determination is NO, the process returns to step knob S2, and if the determination is YES, the process advances to step 346. In step S46, it is determined whether or not the pressure switch 21b for detecting occlusion pressure, which has been set while the set pressure is between 450 and 350 mmH2O, is on. If this determination is No, the process returns to step S2, and the determination is made as follows. If YES, step S4
Proceed to step 7. In step S47, flag 2 is set to 1, and then the process proceeds to step 348, where counter X4 is incremented (+1). After executing step 48, the process proceeds to step S49, where it is determined whether the timer T7 has timed out, that is, whether seven days have elapsed.

When the determination in step S49 is NO, the process returns to step S2, and when the determination is YES, step S50
Proceed to. In step S50, it is determined whether the counter X2 is 2 or less, and if the determination is NO, that is, 3 or more, the process advances to step S51, where the counter X4 and timer T7 are cleared, and then the process returns to step S2. . When the determination in step 50 is YES, the process proceeds to step 352 to display an alarm on the display section 11b and cause the alarm section 11c to generate an alarm sound. Thereafter, the process proceeds to step S53, where it is determined whether or not the recent switch 11d has been operated. Steps 352 and S53 are repeated until the determination becomes YES, and when the determination becomes YES, the process returns to step S1.

By executing steps S45 to S53 described above, it is determined whether or not the number of times that the pressure switch 21b for detecting occlusion pressure is turned on within 7 days after a long period of time (20 minutes or more) without gas flow is 2 or less. That is, it detects whether or not it has occurred three or more times, and if detected, it is determined that a slight gas leak has occurred downstream of the pressure regulator, and a display/alarm is issued to that effect.

This is done based on the fact that the outside air temperature rises and the occlusion pressure detection switch 21b is turned on when no gas has been used for a period of time or more, when no small gas leak has occurred. When the content of the counter X4 is 2 times or less, it can be determined that there is a slight gas leak.

Note that even if the occlusion pressure is normal, the 2-minute timer T4 in step S32 temporarily (
The gas pressure in the gas pipe increases (for less than 2 minutes), and when this is detected, the normal closing pressure is mistakenly judged to be abnormal, so this pressure increase is ignored.

In addition, the two-minute timer T4 and step 13 of step S32
The 18-minute timer T is designed so that even if there is no slight gas leak, the gas pressure in the gas pipe will not rise due to the outside temperature for a certain period of time (20 minutes or less) after the use of gas is stopped. It is provided to ignore the pressure during this period.

In the embodiment described above, the pressure switch 21b for detecting occlusion pressure is also used to detect the presence or absence of a minute gas leak, so even if there is a slight gas leak, the pressure switch 21b for detecting occlusion pressure will not be turned on. Ignoring this fact, I was forced to count the number of times that the pressure switch for detecting the closing force was turned on, assuming that the gas flow rate did not exceed a certain period of time. However, when the use of gas is stopped, a special pressure that is higher than the maximum pressure that rises temporarily regardless of the presence or absence of a minute gas leak, but lower than the pressure that rises due to the temperature difference in the outside air, is used to turn on the gas. When a pressure switch is provided, this pressure switch may be constantly monitored and the number of times it is turned on may be counted.

(Effects) As explained above, according to the present invention, when there is no minute gas leak, the pressure in the gas supply path becomes equal to or higher than the preset pressure due to a rise in outside air temperature, and whenever there is a minute gas leak, the above Focusing on the fact that the pressure never exceeds the set pressure, counting is performed according to the detection of pressure above the preset set pressure, and when the counted value within the preset period is less than the preset counted value, minute gas is detected. Since it is determined that there is a leak, it is possible to automatically detect a minute gas leak under normal gas usage conditions without having to shut off the gas supply for a long time using a gas cutoff valve.

In addition, there is no need to consciously cut off the gas supply path to detect small gas leaks, and there is no need to predict that the gas will not be used before cutting off the gas. .

Furthermore, since counting is performed in accordance with the detection of pressure above a preset set pressure on the condition that no gas flow rate has been detected continuously for a predetermined period of time, the pressure detection means is not connected to other pressures. It can also be used as a means of detecting.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of a micro gas leak detection device according to the present invention, FIGS. 2 and 3 are explanatory diagrams for explaining the principle of detecting a micro gas leak according to the present invention, and FIG. FIG. 5 is a block diagram showing the electronic circuit configuration of the electronic gas meter in FIG. 4. FIG. 6 is a block diagram showing the electronic circuit configuration of the electronic gas meter in FIG. 5. FIG. 7 is a flowchart showing the work performed by the signal processing section in FIG. 6; FIG. 8 is a diagram showing the general configuration of the gas supply system. 3... Gas piping (gas supply path), 20... Signal processing unit (measuring means), 21b... Pressure switch for detecting blockage pressure (pressure detection means), 22... Flow rate switch 7 channels ( Gas flow rate detection means) 1b 3 (1゛S 34-)

Claims (2)

[Claims] (1) A pressure detection means provided in a gas supply path and configured to detect a pressure equal to or higher than a preset set pressure, and a counting means configured to perform counting in response to detection of a pressure equal to or higher than the set pressure by the pressure detection means, A minute gas leak detection device, characterized in that it is determined that minute gas is leaking when the count value of the counting means within a predetermined period is less than or equal to a predetermined count value. (2) a pressure detection means that is provided in the gas supply path and detects a pressure equal to or higher than a preset pressure; and a gas flow rate detection means that detects that there is no gas flow in the gas supply path continuously for a predetermined period of time; and a counting means that performs counting in response to the detection of a pressure equal to or higher than the set pressure by the pressure detection means when the gas flow rate detection means detects that there is no gas flow rate for a predetermined period of time, and for a predetermined period of time. A minute gas leakage detection device, characterized in that it is determined that minute gas is leaking when the count value of the counting means is less than or equal to a predetermined count value.