JP5351505B2 - Measuring device and measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring device and a measuring method capable of suppressing power consumption. <P>SOLUTION: A gas meter 40 includes a microcomputer 47. The microcomputer executes a first processing and a second processing in parallel. The first processing is a processing for measuring a gas flow rate in a channel based on an electric signal output from a flow rate sensor 41 during a measuring time within a first prescribed time. The second processing is a processing for determining that the gas flow rate in the channel is changed based on the electric signal from the flow rate sensor 41, in each second prescribed time which is shorter than the measuring time. Further, the microcomputer 47 uses the electric signal acquired from the flow rate sensor 41 during the measuring time for both of measurement of the gas flow rate in the first processing and for determination of a gas flow rate change in the second processing. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a measuring apparatus and a measuring method.

Conventionally, ultrasonic and thermal gas meters are known. In such a gas meter, the gas flow rate is measured once every about 2 seconds (see, for example, Patent Document 1 and Patent Document 2).
JP 2008-202948 A JP 2001-324368 A

  However, since the gas meter measures the gas flow rate for 24 hours at an interval of once every 2 seconds, the power consumption is not small. In addition, when the measurement interval is not limited to once every 2 seconds and is measured at a shorter measurement interval such as once every 0.2 seconds, the power consumption is further increased. In particular, the gas meter must be driven by a battery for 10 years during the verification period, and it is important to reduce power consumption. This problem is not limited to a gas meter as long as it is a measurement device that measures the flow rate of gas, and is a common problem.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a measuring apparatus and a measuring method capable of suppressing power consumption.

  The measuring device according to the present invention includes a flow rate sensor that outputs an electrical signal corresponding to a gas flow rate in a flow path, and an electrical signal output from the flow rate sensor during a measurement time within a first predetermined time. A first process for measuring the gas flow rate of the gas flow is performed, and it is determined at every second predetermined time shorter than the measurement time that the gas flow rate in the flow path has changed based on an electrical signal from the flow rate sensor. A microcomputer unit that executes two processes, and the microcomputer unit executes the first process and the second process in parallel, and outputs an electric signal obtained from the flow sensor during the measurement time, It is used for both measurement of the gas flow rate in the processing and judgment of gas flow rate change in the second processing.

  According to this measuring apparatus, the first process and the second process are executed in parallel, and the electric signal obtained from the flow rate sensor during the measurement time is used to measure the gas flow rate in the first process, and the second process. Used for both judgment of gas flow rate change in processing. For this reason, the flow sensor is driven to acquire an electrical signal for measurement of the gas flow rate in the first process, and the electrical signal is acquired by driving the flow sensor to determine a gas flow rate change in the second process. Compared with the power consumption can be suppressed.

  Moreover, in the measurement apparatus of the present invention, the microcomputer unit does not continuously exceed the predetermined value for the gas flow rate in the flow path a plurality of times in the first process when the first process and the second process are performed in parallel. In this case, it is preferable to execute only the second process.

  According to this measuring apparatus, only the second process is performed when the gas flow rate in the flow path does not exceed a predetermined value continuously several times in the first process when the first process and the second process are performed in parallel. Therefore, when the flow rate does not exceed a predetermined value (for example, 1.5 L / hr) and there is no gas flow, that is, there is no need for the integration of the flow rate and the use of gas appliances or gas leakage. In this case, only the second process is performed without performing the first process, and the power consumption can be further reduced.

  In the measuring device of the present invention, the microcomputer unit detects at least one of the gas flow rate and the gas pressure every third predetermined time, and determines the use of the gas appliance installed on the downstream side of the gas flow path. It is preferable to execute a third process for determining whether or not a gas leak has occurred.

  According to this measuring device, since the third process is performed, it is possible to determine the use of the gas appliance and to determine the gas leakage.

  In the measurement apparatus of the present invention, when the microcomputer unit determines that the gas flow rate in the flow path has changed in the second process when the first process and the second process are performed in parallel, Preferably, the three processes are executed for a specific time, and after this execution, the first process and the second process are again executed in parallel.

  According to this measuring apparatus, when it is determined that the gas flow rate in the flow path has changed in the second process when the first process and the second process are performed in parallel, the third process is performed for a specific time after the determination. After the execution, the first process and the second process are again executed in parallel. For this reason, when the gas flow rate changes, the third process is executed, the use of the gas appliance and the gas leakage are determined, and the first process and the second process are executed again in parallel. That is, after determining the gas leakage or the like in the third process, the gas flow rate is measured in the first process, and the normal gas flow rate can be measured after confirming safety.

  Further, in the measurement apparatus of the present invention, the microcomputer unit, when executing the third process, calculates the frequency and amplitude of the waveform from the waveform obtained by detecting at least one of the gas flow rate and the gas pressure every third predetermined time. Based on the value obtained by obtaining at least one of them, or the calculation result indicating the state of at least one of the frequency and amplitude of the waveform, it is a gas leak or the use of a gas appliance having a governor out of the gas appliance, It is preferable to determine whether the gas appliance is not used.

  According to this measuring apparatus, the value obtained by obtaining at least one of the frequency and amplitude of the waveform from the waveform obtained by detecting at least one of the gas flow rate and the gas pressure every third predetermined time, or the waveform Based on the calculation result indicating the state of at least one of frequency and amplitude, it is determined whether the gas leak or the use of a gas appliance having a governor or a gas appliance having no governor is used. . Here, there is a characteristic difference in the frequency and amplitude of the waveform of pressure and flow rate when a gas leak occurs, when the gas appliance having the governor is started, and when the gas appliance without the governor is started. Therefore, it is judged by this characteristic difference whether it is a gas leak or the use of a gas appliance with a governor or a gas appliance without a governor, and a false detection of a gas leak judgment. It can be connected to prevention.

  In the measurement apparatus of the present invention, the flow rate sensor is an ultrasonic sensor, and the microcomputer unit determines whether or not the propagation time of the ultrasonic wave has changed compared to the past propagation time when the second process is executed. Based on this, it is preferable to determine whether or not the gas flow rate in the flow path has changed.

  According to this measuring apparatus, the flow rate sensor is an ultrasonic sensor, and the microcomputer unit changes the gas flow rate in the flow path based on whether or not the ultrasonic propagation time has changed during the execution of the second process. Determine whether or not. Here, the gas flow rate is obtained from the propagation time. However, if only the change in the flow rate is detected as in the second process, only the change in the propagation time may be monitored without obtaining the flow rate. Thereby, unnecessary calculations are omitted, and the power consumption can be further reduced.

  Further, the measurement method of the present invention includes a first process for measuring a gas flow rate in the flow path based on an electrical signal output from the flow rate sensor during the measurement time within the first predetermined time, and an electrical flow from the flow rate sensor. Based on the signal, a second process for determining that the gas flow rate in the flow path has changed every second predetermined time shorter than the measurement time is executed in parallel, and obtained from the flow sensor during the measurement time. The obtained electrical signal is used for both the measurement of the gas flow rate in the first process and the determination of the change in the gas flow rate in the second process.

  According to this measurement method, the first process and the second process are performed in parallel, and the electric signal obtained from the flow rate sensor during the measurement time is used to measure the gas flow rate in the first process, and the second process. Used for both judgment of gas flow rate change in processing. For this reason, the flow sensor is driven to acquire an electrical signal for measurement of the gas flow rate in the first process, and the electrical signal is acquired by driving the flow sensor to determine a gas flow rate change in the second process. Compared with the power consumption can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the measuring device and measuring method which can suppress power consumption can be provided.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a gas supply system including a measuring device according to an embodiment of the present invention. The gas supply system 1 supplies fuel gas to each gas appliance 10, and includes a plurality of gas appliances 10, a gas supply source regulator 20, pipes 31 and 32, a gas meter (measuring device) 40, and the like. It has. In the example illustrated in FIG. 1, the gas meter 40 is described as an example of a measuring device, but the measuring device is not limited to the gas meter 40 and may be other devices that measure the gas flow rate.

  The adjuster 20 adjusts the fuel gas from the upstream to a predetermined pressure and flows it through the first pipe 31. The first pipe 31 connects the regulator 20 and the gas meter 40. The second pipe 32 is a pipe that connects the gas meter 40 and the gas appliance 10. The gas meter 40 measures the flow rate of the fuel gas and displays the integrated flow rate. In such a gas supply system 1, a flow path connected to the first pipe 31 and the second pipe 32 is formed in the gas meter 40, and the fuel gas flowing through the regulator 20 flows from the first pipe 31 to the gas meter 40, And the gas appliance 10 is reached through the second pipe 32 and burned in the gas appliance 10.

  The gas appliance 10 generally includes a shut-off valve 12, a governor 13, and a burner 14. The shut-off valve 12 is a valve provided in the gas appliance 10. The governor 13 has a governor inner valve 13a, and adjusts the pressure of the gas supplied to the burner 14 of the gas appliance 10 by the opening degree of the governor inner valve 13a. The pressure-adjusted fuel gas reaches the burner 14 through the nozzle 13b at the tip of the governor 13 and burns. Note that not all the gas appliances 10 have the governor 13, and some gas appliances 10 do not have the governor 13 such as a gas stove.

  FIG. 2 is a side sectional view showing an example of the governor 13 shown in FIG. In addition, in FIG. 2, only an example of the governor 13 is shown, and the configuration of the governor 13 is not limited to that shown in FIG. Further, the governor 13 shown in FIG. 2 is illustrated with the nozzle 13b shown in FIG. 1 omitted.

  As shown in FIG. 2, the governor 13 uses a part of the internal space formed by the outer wall 13c and the governor cap 13d as a gas flow path. Such a governor 13 includes a diaphragm 13e, an adjustment spring 13f, and an adjustment screw 13g in the internal space in addition to the governor inner valve 13a.

  The diaphragm 13 e is a film-like member that partitions the internal space of the governor 13. A governor inner valve 13a is attached to the diaphragm 13e on one side (flow channel side). Further, an adjustment spring 13f is attached to the other side (side not functioning as a flow path) of the diaphragm 13e. The adjustment spring 13f has a diaphragm 13e attached to one end and an adjustment screw 13g attached to the other end. The adjustment screw 13g is structured to be fixed to the inner wall of the governor 13 in which the thread groove is formed, and the compression rate of the adjustment spring 13f can be changed by changing the fixing position with the thread groove. Further, the adjusting screw 13g is not exposed to the outside, and has a structure covered with a governor cap 13d.

  The outer wall 13c of the governor 13 is formed with an air hole 13h that communicates with the other side of the diaphragm 13e. For this reason, the other side of the diaphragm 13e is air pressure. Further, in the example shown in FIG. 2, the governor inner valve 13a has a hemispherical shape, and the opening ratio of the passage port 13i can be controlled by vertical movement.

  In such a governor 13, when the gas pressure on the gas inlet side increases, the diaphragm 13e is pushed up, and at the same time, the governor inner valve 13a attached to the diaphragm 13e is also raised. Thereby, the opening ratio of the passage port 13i becomes small, and the gas flow rate decreases. On the other hand, when the gas pressure on the gas inlet side is lowered, the diaphragm 13e is lowered, and at the same time, the governor inner valve 13a attached to the diaphragm 13e is also lowered. Thereby, the opening ratio of the passage port 13i increases, and the gas flow rate increases. In this manner, the governor 13 adjusts the downstream pressure by keeping the downstream flow rate constant with respect to the upstream pressure fluctuation.

  FIG. 3 is a configuration diagram of the gas meter 40 according to the embodiment of the present invention. The gas meter 40 shown in the figure includes a flow sensor 41, a pressure sensor 42, a microcomputer (microcomputer unit) 47, and a drive circuit 48.

  The flow rate sensor 41 is installed in the flow path in the gas meter 40 and outputs an electrical signal corresponding to the gas flow rate in the flow path. When the gas meter 40 according to the present embodiment is an ultrasonic type gas meter, the flow sensor 41 is configured by two acoustic transducers composed of, for example, piezoelectric vibrators arranged at a predetermined distance in the flow path. When the gas meter 40 according to the present embodiment is a gas meter equipped with a thermal sensor such as a flow sensor, the gas meter 40 includes a heater that generates a temperature distribution and a thermopile that generates a signal corresponding to the temperature distribution.

  The pressure sensor 42 is for detecting the gas pressure of the gas present in the flow path in the gas meter 40. The pressure sensor 42 is not limited to the flow path in the gas meter 40, and may be installed in the first pipe 31 or the second pipe 32 existing outside the gas meter 40 if possible. Similarly, the installation location of the flow sensor 41 can be changed.

  In this embodiment, the signals from the flow sensor 41 and the pressure sensor 42 are directly input to the microcomputer 47 in FIG. 3, but other elements such as an amplifier may be added between the two depending on circumstances. .

  The microcomputer 47 controls the entire gas meter 40 and performs flow rate integration control, display control, cutoff valve cutoff control, and the like. Further, in the present embodiment, the microcomputer 47 executes the first to third processes in three measurement modes, that is, the simple measurement mode, the normal measurement mode, and the high-speed measurement mode. That is, the microcomputer 47 executes the second process in the simple measurement mode, executes the first process and the second process in parallel in the normal measurement mode, and executes the third process in the high-speed measurement mode.

  The drive circuit 48 controls driving of the flow sensor 41 and the pressure sensor 42, and includes a simple measurement mode drive circuit 48a, a high-speed measurement mode drive circuit 48b, and a regular measurement mode drive circuit 48c. These drive circuits 48a to 48c correspond to the three measurement modes described above. Therefore, when it is desired to drive the gas meter 40 in the simple measurement mode (that is, when it is desired to execute the second process), the simple measurement mode drive circuit 48a functions, and when it is desired to drive the gas meter 40 in the high-speed measurement mode (that is, the third process is performed). The high-speed measurement mode drive circuit 48b functions when it is desired to execute it. When it is desired to drive the gas meter 40 in the normal measurement mode (that is, when it is desired to execute the first process and the second process in parallel), the normal measurement mode drive circuit 48c functions.

  Here, the first to third processes will be described. The first process is a process of measuring the gas flow rate in the flow path based on the electrical signal output from the flow sensor 41. In this process, the gas flow rate in the flow path is measured based on the electrical signal output from the flow rate sensor 41 during the measurement time (about 540 ms) within the first predetermined time (about 2 seconds). This first process is executed in the normal measurement mode as described above. Therefore, in the normal measurement mode, the gas meter 40 increases the value of the integrated flow rate displayed on the meter body according to the gas flow rate.

  The second process is a process for determining that the gas flow rate in the flow path has changed based on the electrical signal from the flow rate sensor 41. The determination interval for determining that the gas flow rate in the flow path has changed is every second predetermined time (0.1 seconds) and shorter than the measurement time (540 ms). This second process is executed in the normal measurement mode and the simple measurement mode as described above. In the simple measurement mode, the gas pressure may be detected as necessary.

  In the third process, at least one of the gas flow rate and the gas pressure is detected every third predetermined time (1 ms) to determine the use of the gas appliance 10 installed on the downstream side of the gas flow path, and the gas leakage is detected. This is a process for determining whether or not it has occurred. This third process is executed in the high-speed measurement mode. In this process, the gas meter 40 captures the change waveform of the gas pressure, determines the use of the gas appliance 10 installed on the downstream side of the gas flow path from the frequency and amplitude of the waveform, and whether or not a gas leak has occurred. It will be judged. Note that there is a correlation between a change in gas pressure and a change in gas flow rate. For this reason, in the third process, the gas flow rate may be measured at a measurement interval of 1 ms, or both the gas pressure and the gas flow rate may be measured at a measurement interval of 1 ms. Further, the third process is executed in the high-speed measurement mode as described above.

  In the gas supply system 1 as described above, the mode of the gas meter 40 is changed as follows. FIG. 4 is a state transition diagram showing an outline of mode transition of the gas meter 40 according to the present embodiment. As shown in FIG. 4, first, when no gas is used, the gas meter 40 is in a simple measurement mode. At this time, the microcomputer 47 executes the second process.

  Thereafter, it is determined that the flow rate has changed in the simple measurement mode (S1). At this time, the microcomputer 47 generates a trigger signal for shifting from the simple measurement mode to the high-speed measurement mode. Then, the drive circuit 48 inputs the trigger signal and causes the high-speed measurement mode drive circuit 48b to function. Thereby, the gas meter 40 shifts to the high-speed measurement mode.

  In addition, when the gas meter 40 shifts to the high-speed measurement mode, the gas meter 40 executes the third process, and whether or not the gas meter 40 corresponds to one of the use state of the gas appliance 10 with the governor, use of the gas appliance 10 without the governor, and gas leakage. Judging.

  Further, the gas meter 40 performs pressure measurement for a specific time (for example, 2 seconds) in the high-speed measurement mode. And after specific time progress, the microcomputer 47 generates the trigger signal for making it transfer to high speed measurement mode from regular measurement mode. As a result, the drive circuit 48 causes the normal measurement mode drive circuit 48c to function and shifts the gas meter 40 to the normal measurement mode (S2).

  When it is determined that gas leakage has occurred in the high-speed measurement mode, the gas meter 40 operates the shut-off valve to close the flow path and prevent gas leakage. In the high-speed measurement mode, in a special case, the high-speed measurement mode is continued even after a specific time has elapsed (S3). Here, the special case is, for example, a case where the gas appliance 10 has failed to ignite once and is expected to start the ignition operation again immediately after the failure.

  When shifting to the normal measurement mode, the microcomputer 47 executes the first process and the second process in parallel.

  Then, it is assumed that a flow rate exceeding a predetermined value (for example, 1.5 L / hr) is not detected in the normal measurement mode. That is, it is assumed that the flow rate detected in the first process is 1.5 L / hr or less (S4). In this case, the microcomputer 47 generates a trigger signal for shifting from the normal measurement mode to the simple measurement mode. And the drive circuit 48 makes the simple measurement mode drive circuit 48a function, and makes the gas meter 40 transfer to simple measurement mode. The trigger signal for shifting from the normal measurement mode to the simple measurement mode is output when the flow rate is 1.5 L / hr or less, but is not limited to this, and the flow rate is 1.5 L / hr or less. It is desirable to output when is continuously performed a plurality of times. Thereby, when the flow rate is instantaneously 1.5 L / hr or less due to pulsation or the like, flow measurement can be continued without shifting to the simple measurement mode.

  By the way, when there is a flow rate change in the normal measurement mode, that is, when it is determined that there is a flow rate change in the second process, the microcomputer 47 generates a trigger signal for shifting from the normal measurement mode to the high-speed measurement mode. And the drive circuit 48 makes the high-speed measurement mode drive circuit 48b function, and makes the gas meter 40 transfer to high-speed measurement mode (S5). Due to the transition to the high-speed measurement mode, the gas meter 40 has a gas leak when a new gas appliance 10 is used during gas use and from a location different from the gas appliance 10 being used during gas use. In some cases, it can be determined whether it is the use of a new gas appliance 10 or a gas leak.

  Next, the use of the gas appliance 10 in the high-speed measurement mode and a determination method for gas leakage will be described. When the gas appliance 10 with the governor is used, when the gas appliance 10 without the governor is used, and when a gas leak occurs, different pressure changes are shown. Specifically, when the pressure change is on the vertical axis and the time is on the horizontal axis, the amplitude and frequency of the pressure change are characteristic. In the high-speed measurement mode, the microcomputer 47 determines whether or not the governor-equipped gas appliance 10 is used, whether or not the governor-less gas appliance 10 is used, and whether a gas leak has occurred, from the amplitude and frequency of the pressure change. Determine whether.

  FIG. 5 is a graph showing how the pressure changes when the use of the gas appliance 10 with the governor is started. In FIG. 5, the vertical axis represents the pressure change amount (kPa), and the horizontal axis represents the elapsed time (seconds) after the use of the governor-equipped gas appliance 10 is started.

  When the use of the gas appliance 10 with the governor is started, the pressure becomes a stable state after exhibiting the predetermined amplitude shown in FIG. Specifically, immediately after the start of use of the gas appliance 10 with the governor, after showing a pressure drop to just “−0.1” kPa (see symbol a1), the pressure rises to about “0.05” kPa. (See symbol a2). After that, the pressure shows a pressure drop to about “−0.05” kPa (see symbol a3), and then shows a pressure rise to about “0.05” kPa (see symbol a4). Thereafter, the pressure repeatedly oscillates while the amplitude gradually decreases, and finally becomes a stable state in which there is no pressure change.

  The reason why such pressure vibration occurs is that an adjustment spring 13 f is provided in the governor 13. That is, when the use of the gas appliance 10 with the governor is started, the adjustment spring 13f vibrates, the governor inner valve 13a also vibrates, and the opening ratio of the passage port 13i changes gradually and gradually. Because it does.

  In particular, at the start of use of the gas appliance 10 with a governor, characteristics are seen in the frequency and amplitude of pressure vibration. Specifically, since the adjustment spring 13f vibrates in small increments, the pressure shows fine vibration. As a result, the pressure waveform contains many relatively high frequency components. Moreover, since the passage opening 13i becomes larger or smaller due to the vibration of the adjustment spring 13f at the start of use of the gas appliance 10 with a governor, the pressure waveform shows a large amplitude.

なる演算式で表すことができる。ここで、Ｃは振幅を示し、ｋは摩擦力（減衰定数）を示し、ωは復元力を示し、αは初期位置を示している。この式は多くの周波数ｆ_ｉ＝ω_ｉ／２πの振動の重ね合わせであることを示している。 The pressure P is

It can be expressed by the following equation. Here, C indicates the amplitude, k indicates the frictional force (attenuation constant), ω indicates the restoring force, and α indicates the initial position. This equation indicates that this is a superposition of vibrations of many frequencies f _i = ω _i / 2π.

  FIG. 6 is a graph showing the pressure change when the use of the governorless gas appliance 10 is started. In FIG. 6, the vertical axis represents the pressure change amount (kPa), and the horizontal axis represents the elapsed time (seconds) after the use of the governorless gas appliance 10 is started.

  When the use of the governorless gas appliance 10 is started, the pressure is in a stable state after showing the predetermined amplitude shown in FIG. Specifically, immediately after the start of use of the gas appliance 10 with the governor, after showing a pressure drop to “−0.1” kPa (see b1), the pressure rises to about “0.01” kPa. (See symbol b2). Thereafter, the pressure shows a pressure drop to about “−0.05” kPa (see symbol b3). Thereafter, the pressure repeatedly vibrates with no pressure increase. Then, the amplitude gradually decreases, and finally a stable state in which there is no pressure change is obtained. The reason why such pressure vibration occurs is as follows.

  FIG. 7 is a schematic view showing a state of supply of fuel gas in the governorless gas appliance 10. As shown in FIG. 7, when the governorless gas appliance 10 is used, the fuel gas reaches the burner 14 and the like from the second pipe 32 through the nozzle holder 100. Here, when a gas having a flow velocity flows into the nozzle holder 100, the flow rate does not decrease suddenly due to the inertial force, but the gas is compressed and the pressure rises. Thereafter, the inflow flow velocity becomes small (in some cases, a reverse flow) due to the increased pressure, and the pressure decreases. By repeating this, vibration of compression and expansion occurs.

  As described above, the pressure oscillates when the gas appliance with governor 10 is used and when the gas appliance 10 without governor is used. However, when the pressure waveform shown in FIG. 6 is compared with the pressure waveform shown in FIG. 5, there are the following differences.

  First, the governor-equipped gas appliance 10 has a substance that vibrates finely like the adjustment spring 13f, whereas the governor-less gas appliance 10 does not have such a substance. Therefore, although the pressure waveform shown in FIG. 6 shows vibration in the same manner as the pressure waveform shown in FIG. 5, the vibration frequency as a whole is lower than the pressure waveform shown in FIG.

  Further, in the case of the gas appliance 10 with the governor, the amplitude is increased by the vibration of the adjustment spring 13f. However, in the case of the gas appliance 10 with the governor, there is no adjustment spring 13f, and vibration due to the compressibility of the nozzle holder 100 occurs. There is only. For this reason, the pressure waveform shown in FIG. 6 has a smaller amplitude than the pressure waveform shown in FIG.

  From such characteristics, the microcomputer 47 can determine whether the gas appliance with governor 10 is used or whether the gas appliance 10 without governor is used.

  FIG. 8 is a graph showing a state of pressure change at the time of gas leakage. In FIG. 8, the vertical axis represents the pressure change amount (kPa), and the horizontal axis represents the elapsed time (seconds) after the gas leak occurred.

  As shown in FIG. 8, when a gas leak occurs, the pressure gradually decreases without showing a clear vibration. Thus, in the case of gas leakage, neither the vibration of the adjustment spring 13f nor the vibration due to the compressibility of the nozzle holder 100 occurs, so no clear vibration is seen in the pressure waveform.

  As described above, there is a characteristic difference in the frequency and amplitude of the pressure waveform between the start of use of the gas appliance 10 with governor, the start of use of the gas appliance 10 without governor, and the occurrence of gas leakage. From the above characteristics, the microcomputer 47 can determine whether the gas appliance 10 with the governor is used, the gas appliance 10 without the governor, or the gas leak. In determining whether or not the gas appliance 10 with the governor is used, the microcomputer 47 may use a value of frequency or amplitude, or a calculation result indicating the frequency or amplitude (for example, spectral data obtained by Fourier transform). ) May be used.

  In the gas meter 40 as described above, the first process and the second process are executed in parallel in the normal measurement mode. Next, flow rate measurement in the first process and flow rate change determination in the second process will be described.

  When the gas meter 40 is an ultrasonic gas meter, the ultrasonic gas meter performs the first process as follows, for example. In an ultrasonic gas meter, sensors that oscillate and receive ultrasonic waves are installed upstream and downstream of a straight gas flow path. An ultrasonic wave is oscillated from the upstream and received downstream to measure its propagation time, and the time is changed to oscillate an ultrasonic wave from the downstream and received upstream to measure its propagation time. The reciprocation is measured a plurality of times and the average is taken to measure the flow rate with high accuracy. This method is called a sing-around method.

  On the other hand, in the second process, since it is only necessary to determine that the flow rate has changed, extremely high accuracy is not required. Therefore, the number of ultrasonic oscillations may be smaller than that in the first process. That is, when 80 reciprocations are performed as one flow measurement in the first process, five reciprocations are defined as one flow measurement in the second process. Thereby, the measurement accuracy is ¼ (= √ (5/80)) of the first process. In addition, the current consumption is 1/16.

  As described above, in the first process, for example, 80 times of ultrasonic oscillation is performed to measure the flow rate, and in the second process, for example, 5 times of ultrasonic oscillation is performed to determine the flow rate change. For this reason, when the first process and the second process are executed in parallel in the normal measurement mode, the power consumption for the first process and the power consumption for the second process are added, resulting in a large power consumption. End up. In particular, since the gas meter 40 is required to be driven by a battery for 10 years, an increase in power consumption becomes a problem. However, in the present embodiment, the microcomputer 47 uses the electrical signal obtained from the flow rate sensor 41 during the measurement time for both the measurement of the gas flow rate in the first process and the determination of the change in the gas flow rate in the second process. It is said.

  FIG. 9 is a timing chart showing a state in which the first process is executed alone, the second process is executed alone, and the first process and the second process are executed in parallel. As shown in FIG. 9A, in the first process, ultrasonic oscillation is performed 80 times at a measurement interval of once every 2 seconds, and the propagation time is obtained to calculate the flow rate. Of these, the time required for ultrasonic oscillation is about 540 ms.

  Further, as shown in FIG. 9B, in the second process, the ultrasonic wave is oscillated five times at a measurement interval of once every 0.1 second, the propagation time is obtained and the flow rate is calculated. Therefore, in 2 seconds, 5 × 20 = 100 ultrasonic oscillations are performed. Therefore, if the first process and the second process are executed in parallel, power consumption related to these ultrasonic oscillations and calculations is applied, leading to an increase in power consumption.

  However, in the gas meter 40 according to the present embodiment, the electric signal obtained from the flow rate sensor 41 during the measurement time (540 ms) is used to measure the gas flow rate in the first process and to determine the change in the gas flow rate in the second process. It is supposed to be used for both. That is, as shown in FIG. 9C, the ultrasonic oscillation in the first process and the ultrasonic oscillation in the second process are performed in the time zone of 540 ms that is the measurement time. In other words, ultrasonic oscillation is performed. Therefore, the increase in power consumption is suppressed by using the ultrasonic oscillation in the first process for the ultrasonic oscillation in the second process.

  Specifically, in this embodiment, the ultrasonic oscillation in the first process is performed 80 times at the above-described timing, the ultrasonic oscillation in the second process is not performed, and the second process is the closest in time. Whether or not there has been a change in the flow rate is determined using the ultrasonic oscillation data in the first process for each batch. As a result, in the time zone of 540 ms, the power consumption related to the ultrasonic oscillation or the like of the second process is reduced.

  In the above, in the second process, an example in which the propagation time is obtained and the flow rate is calculated from the obtained propagation time has been described. However, the present invention is not limited to this, and the ultrasonic propagation time has changed in comparison with the past propagation time. Whether or not the gas flow rate in the flow path has changed may be determined based on whether or not. For example, if the current propagation time changes compared to the previous propagation time, it is understood that at least the flow rate has changed. Thereby, unnecessary calculation can be omitted and power consumption can be further suppressed. In the above description, the ultrasonic gas meter has been described, but the same applies to a thermal gas meter.

  Next, with reference to a flowchart, the measuring method by the gas meter 40 which concerns on this embodiment is demonstrated. FIG. 10 is a flowchart showing details of the measurement method of the gas meter 40 according to the present embodiment, and shows the operation in the simple measurement mode. That is, FIG. 10 shows the operation of the gas meter 40 when only the second process is executed.

  In the simple measurement mode, the microcomputer 47 first determines whether or not a second predetermined time (specifically, 0.1 second) has elapsed (S11). When it is determined that the second predetermined time has not elapsed (S11: NO), this process is repeated until it is determined that the second predetermined time has elapsed. If it is determined that the second predetermined time has elapsed (S11: YES), the microcomputer 47 resets the time measured (S12). Then, the microcomputer 47 obtains the ultrasonic oscillation data for five times and calculates the propagation time (S13).

  Next, the microcomputer 47 determines whether or not the currently calculated propagation time has changed compared to the previously calculated propagation time (S14). In the process of step S14, the present propagation time may be compared with the average value of the past several propagation times as well as the present propagation time and the previous propagation time. If it is determined that there is no change in the propagation time (S14: NO), the process proceeds to step S11.

  On the other hand, if it is determined that the propagation time has changed (S14: YES), the microcomputer 47 generates a trigger signal (S15). Thereby, the high-speed measurement mode drive circuit 48b of the drive circuit 48 functions, and the measurement mode shifts from the simple measurement mode to the high-speed measurement mode (S16). Thereafter, the process shown in FIG. 10 ends.

  FIG. 11 is a flowchart showing details of the measurement method of the gas meter 40 according to the present embodiment, and shows the operation in the high-speed measurement mode. That is, FIG. 11 shows the operation of the gas meter 40 when executing the third process.

  As shown in FIG. 11, in the high-speed measurement mode, the microcomputer 47 determines whether or not a third predetermined time (specifically, 0.001 second) has elapsed (S21). If it is determined that the third predetermined time has not elapsed (S21: NO), this process is repeated until it is determined that the third predetermined time has elapsed. If it is determined that the third predetermined time has elapsed (S21: YES), the microcomputer 47 resets the time measured (S22). And the microcomputer 47 memorize | stores the detected gas pressure while detecting the gas pressure in a flow path based on the signal from the pressure sensor 42 (S23).

  Thereafter, the microcomputer 47 determines whether or not a specific time (specifically, 2 seconds) has elapsed (S24). In this process, the microcomputer 47 determines whether or not a specific time has elapsed depending on whether or not a predetermined number (eg, 300 to 1000) of pressure data has accumulated. If it is determined that the specific time has not elapsed (S24: NO), the process proceeds to step S21.

  On the other hand, if it is determined that the specific time has elapsed (S24: YES), the microcomputer 47 determines use of the gas appliance 10 or gas leakage based on the gas pressure data measured and stored in step S23 during the specific time. (S25). Thereafter, the microcomputer 47 determines whether or not there is no gas leakage in the process of step S25 (S26).

  If it is determined that there is no gas leak (S26: YES), the microcomputer 47 generates a trigger signal (S27). As a result, the normal measurement mode drive circuit 48c of the drive circuit 48 functions, and the measurement mode shifts from the high-speed measurement mode to the normal measurement mode (S28). Thereafter, the process shown in FIG. 11 ends.

  On the other hand, if it is not determined that there is no gas leak (S26: NO), that is, if it is determined that there is a gas leak, the microcomputer 47 shuts off the shutoff valve and issues an alarm (S29). Thereafter, the process shown in FIG. 11 ends.

  FIG. 12 is a flowchart showing details of the measurement method of the gas meter 40 according to the present embodiment, and shows the operation in the regular measurement mode. That is, FIG. 12 shows the operation of the gas meter 40 when executing the third process.

  As shown in FIG. 12, in the normal measurement mode, the microcomputer 47 first determines whether or not the ultrasonic wave has been oscillated 80 times (S31). When it is determined that the oscillation has been performed 80 times (S31: YES), the microcomputer 47 measures the flow rate from the propagation time (S32). Thereafter, the microcomputer 47 determines whether or not the flow rate exceeds a predetermined value (for example, 1.5 L / hr) (S33).

  If it is determined that the flow rate exceeds the predetermined value (S33: YES), the microcomputer 47 integrates the flow rate measured in step S32 (S34), and the process proceeds to step S31.

  On the other hand, when determining that the flow rate does not exceed the predetermined value (S33: NO), the microcomputer 47 generates a trigger signal (S35). Thereby, the simple measurement mode drive circuit 48a of the drive circuit 48 functions, and the measurement mode shifts from the normal measurement mode to the simple measurement mode (S36). Thereafter, the process shown in FIG. 12 ends. In the process of step S33, if “NO” is determined only once, the process proceeds to the process of step S35. However, the process is not limited to this, and if “NO” is determined in succession a plurality of times in step S33. In addition, it is desirable to proceed to the process of step S35. This is because it is possible to prevent a transition to the simple measurement mode when the flow rate does not instantaneously exceed a predetermined value due to pulsation.

  By the way, when it is determined that the oscillation has not been performed 80 times (S31: NO), the microcomputer 47 determines whether or not it is currently in the measurement time (S37). If it is determined that it is during the measurement time (S37: YES), the microcomputer 47 determines whether or not a second predetermined time (specifically, 0.1 second) has elapsed (S38). If it is determined that the second predetermined time has not elapsed (S38: NO), the process proceeds to step S31. On the other hand, if it is determined that the second predetermined time has elapsed (S38: YES), the microcomputer 47 resets the time measured for the second predetermined time (S39). And the microcomputer 47 acquires the data for the latest 5 times about the ultrasonic oscillation of a 1st process (S40). Thereafter, the microcomputer 47 calculates the propagation time (S44). That is, as described with reference to FIG. 9C, the microcomputer 47 calculates the propagation time using the data for five of the 80 ultrasonic oscillations in the first process. Thereafter, the process proceeds to step S45.

  If it is determined that the measurement time is not currently being reached (S37: NO), the microcomputer 47 determines whether or not a second predetermined time (specifically, 0.1 second) has elapsed (S41). If it is determined that the second predetermined time has not elapsed (S41: NO), the process proceeds to step S31. On the other hand, if it is determined that the second predetermined time has elapsed (S41: YES), the microcomputer 47 resets the time measured for the second predetermined time (S42). And the microcomputer 47 acquires the data for the latest 5 times about the ultrasonic oscillation of a 2nd process (S43). Thereafter, the microcomputer 47 calculates the propagation time (S44). That is, since it is out of the measurement time, the microcomputer 47 calculates the propagation time by performing the ultrasonic oscillation 5 times without using the partial data of the ultrasonic oscillation 80 times as usual. Thereafter, the process proceeds to step S45.

  In step S45, the microcomputer 47 determines whether or not the currently calculated propagation time has changed compared to the previously calculated propagation time (S45). In the process of step S45, as in the process of step S14, not only when comparing the current propagation time with the previous propagation time, the current propagation time and the average value of the past several propagation times are used. You may make it compare. If it is determined that there is no change in the propagation time (S45: NO), the process proceeds to step S31.

  On the other hand, if it is determined that the propagation time has changed (S45: YES), the microcomputer 47 generates a trigger signal (S46). As a result, the high-speed measurement mode drive circuit 48b of the drive circuit 48 functions, and the measurement mode shifts from the simple measurement mode to the high-speed measurement mode (S47). Thereafter, the process shown in FIG. 12 ends.

  FIG. 13 is a flowchart showing details of step S25 shown in FIG. 11, and shows processing related to use of the gas appliance 10 and determination of gas leakage. As shown in FIG. 13, first, the microcomputer 47 analyzes the frequency of the waveform of the gas pressure stored in step S23 of FIG. 11 (S51) and analyzes the amplitude (S52).

  Thereafter, the microcomputer 47 determines whether or not a frequency component equal to or higher than the discriminant value is included in the waveform based on the analysis result of step S51 (S53). If it is determined that a frequency component equal to or higher than the discriminant value is included (S53: YES), that is, if the frequency component includes many high frequency components such as the pressure waveform shown in FIG. 10 is used (S54). Then, the process illustrated in FIG. 13 ends, and the process proceeds to step S26 in FIG.

  If it is determined that the frequency component equal to or higher than the discriminant value is not included in the waveform (S53: NO), the microcomputer 47 determines the amplitude value of the first peak (that is, the first amplitude after the pressure changes). The maximum value when the value increases in the positive direction, or the value when the amplitude becomes the maximum in the positive direction throughout the whole) is a predetermined amount as the original pressure (the pressure of “0” on the vertical axis in FIG. 5). It is determined whether or not it is equal to or greater than the added value (S55). When it is determined that the amplitude value of the first peak is equal to or larger than the value obtained by adding a predetermined amount to the original pressure (S55: YES), the microcomputer 47 determines that the gas appliance 10 with the governor is used (S54). Then, the process illustrated in FIG. 13 ends, and the process proceeds to step S26 in FIG.

  On the other hand, if it is determined that the amplitude value of the first mountain is not equal to or greater than the value obtained by adding a predetermined amount to the original pressure (S55: NO), the microcomputer 47 determines that the amplitude value of the first mountain is substantially equal to the original pressure. It is determined whether or not (specifically, the original pressure ± the specified value) (S56). If it is determined that the amplitude value of the first peak is substantially the same as the original pressure (S56: YES), the microcomputer 47 determines that the governorless gas appliance 10 is used (S57). Then, the process illustrated in FIG. 12 ends, and the process proceeds to step S26 in FIG.

  If it is determined that the amplitude value of the first mountain is not substantially equal to the original pressure (S56: NO), the microcomputer 47 determines that the amplitude value of the first mountain is equal to or less than the value obtained by subtracting a predetermined amount from the original pressure. It is determined whether or not (S58). When it is determined that the amplitude value of the first peak is equal to or less than a value obtained by subtracting a predetermined amount from the original pressure (S58: YES), the microcomputer 47 detects a flow rate that is equal to or greater than a specified amount based on a signal from the flow rate sensor 41. It is determined whether or not to be performed (S59).

  When it is determined that a flow rate equal to or greater than the specified amount is detected (S59: YES), that is, the characteristics of frequency and amplitude due to the use of the gas appliance 10 cannot be obtained, the gas pressure in the flow path decreases, and the specified amount If the above flow rate is detected, the microcomputer 47 determines that there is a gas leak (S60). Then, the process illustrated in FIG. 13 ends, and the process proceeds to step S26 in FIG.

  By the way, when it is determined that the amplitude value of the first peak is not less than or equal to the value obtained by subtracting the predetermined amount from the original pressure (S58: NO), and when it is determined that the flow rate exceeding the specified amount is not detected (S59: NO). The microcomputer 47 determines that neither the use of the gas appliance 10 nor the gas leakage falls (S61). Then, the process illustrated in FIG. 13 ends, and the process proceeds to step S26 in FIG.

  Note that use of the gas appliance 10 and gas leakage are not limited to those illustrated in FIG. 13, and may be determined by other methods, for example. For example, if the microcomputer 47 determines “YES” in step S53 or step S55, the microcomputer 47 determines that the gas appliance with governor 10 is used, but not limited to this, “YES” in both step S53 and step S55. If it is determined, it may be determined that the gas appliance with governor 10 is used.

  Further, the microcomputer 47 may determine that the governor-equipped gas appliance 10 is used when the attenuation coefficient of the pressure waveform is equal to or less than a predetermined value. Further, the microcomputer 47 determines that the amplitude value of the first peak is the amplitude value of the first valley (that is, the minimum value when the amplitude first increases in the negative direction after the pressure changes, When the amplitude is smaller than the value when the amplitude is increased in the negative direction, it may be determined that the gas appliance 10 with the governor is used. Furthermore, you may judge use of the gas appliance 10 with a governor combining various above-mentioned content.

  Thus, according to the gas meter 40 and the measurement method according to the present embodiment, the first process and the second process are executed in parallel, and the electrical signal obtained from the flow sensor 41 during the measurement time is It is used for both the measurement of the gas flow rate in the first process and the determination of the gas flow rate change in the second process. For this reason, the flow sensor 41 is driven to acquire an electrical signal for measuring the gas flow rate in the first process, and the electrical signal is acquired by driving the flow sensor 41 for determining the gas flow rate change in the second process. Compared with the case where it does, power consumption can be suppressed.

  Further, in the first process when the first process and the second process are performed in parallel, the gas flow rate in the flow path does not exceed a predetermined value (for example, 1.5 L / hr) continuously a plurality of times, Since only the two processes are executed, the flow rate does not exceed a predetermined value and there is no gas flow, that is, when there is no need for the integration of the flow rate, the use of the gas appliance 10 or the judgment of gas leakage. Only the second process is performed without performing one process, and the power consumption can be further reduced.

  Further, since the third process is executed, it is possible to determine the use of the gas appliance 10 and to determine a gas leak.

  In addition, when it is determined that the gas flow rate in the flow path has changed in the second process when the first process and the second process are performed in parallel, the third process is executed for a specific time after the determination. Later, the first process and the second process are executed again in parallel. For this reason, when the gas flow rate changes, the third process is executed, the use of the gas appliance 10 and the gas leakage are determined, and the first process and the second process are executed again in parallel. That is, after determining the gas leakage or the like in the third process, the gas flow rate is measured in the first process, and the normal gas flow rate can be measured after confirming safety.

  In addition, a value obtained by obtaining at least one of the frequency and amplitude of the waveform from the waveform obtained by detecting at least one of the gas flow rate and the gas pressure every third predetermined time, or at least the frequency and amplitude of the waveform Based on the calculation result indicating one state, it is determined whether the gas leak or the use of the gas appliance 10 having the governor 13 among the gas appliances 10 or the use of the gas appliance 10 not having the governor 13 is used. . Here, at the time of occurrence of gas leakage, at the start of use of the gas appliance 10 having the governor 13, and at the start of use of the gas appliance 10 without the governor 13, it is characteristic of the frequency and amplitude of the waveform of pressure and flow rate. There is a difference. Therefore, it is determined whether the gas leakage or the use of the gas appliance 10 having the governor 13 or the use of the gas appliance 10 not having the governor 13 of the gas appliance 10 due to this characteristic difference. It can be connected to prevention of false detection of leak judgment.

  Further, the flow sensor 41 is an ultrasonic sensor, and the microcomputer 47 determines whether or not the gas flow rate in the flow path has changed based on whether or not the ultrasonic propagation time has changed during the execution of the second process. Judging. Here, the gas flow rate is obtained from the propagation time. However, if only the change in the flow rate is detected as in the second process, only the change in the propagation time may be monitored without obtaining the flow rate. Thereby, unnecessary calculations are omitted, and the power consumption can be further reduced.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention. For example, in the present embodiment, the high-speed measurement mode is one measurement interval per 0.001 second, but is not limited thereto, and may be a shorter measurement interval.

  Further, in the present embodiment, from the high-speed measurement mode, only the transition to the regular measurement mode is made, but not limited to this, and when the flow rate detected by the microcomputer 47 in the high-speed measurement mode does not exceed a predetermined value, You may make it transfer to high-speed measurement mode from simple measurement mode.

It is a lineblock diagram of a gas supply system containing a measuring device concerning an embodiment of the present invention. FIG. 2 is a side sectional view showing an example of the governor shown in FIG. 1. It is a lineblock diagram of the gas meter concerning the embodiment of the present invention. It is a state transition diagram which shows the outline of the mode transition of the gas meter which concerns on this embodiment. It is a graph which shows the mode of a pressure change when the use of the gas appliance with a governor is started. It is a graph which shows the mode of a pressure change when the use of a gas appliance without a governor is started. It is the schematic which shows the mode of supply of the fuel gas in a gas appliance without a governor. It is a graph which shows the mode of the pressure change at the time of gas leak. It is a timing chart which shows a situation when the 1st processing is performed independently, when the 2nd processing is performed independently, and when the 1st processing and the 2nd processing are performed in parallel, (a) The timing chart when the first process is executed alone is shown, (b) shows the timing chart when the second process is executed alone, and (c) shows the first process and the second process in parallel. A timing chart when executed is shown. It is a flowchart which shows the detail of the measuring method of the gas meter which concerns on this embodiment, and has shown operation | movement in simple measurement mode. It is a flowchart which shows the detail of the measuring method of the gas meter which concerns on this embodiment, and has shown operation | movement in high-speed measurement mode. It is a flowchart which shows the detail of the measuring method of the gas meter which concerns on this embodiment, and has shown operation | movement in regular measurement mode. It is a flowchart which shows the detail of step S25 shown in FIG. 11, and has shown the process regarding use of a gas appliance, and gas leak judgment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas supply system 10 ... Gas appliance 12 ... Shut-off valve 13 ... Governor 13a ... Governor inner valve 13b ... Nozzle 13c ... Outer wall 13d ... Governor cap 13e ... Diaphragm 13f ... Adjustment spring 13g ... Adjustment screw 13h ... Air hole 14 ... Burner 20 ... Adjuster 31 ... First pipe 32 ... Second pipe 40 ... Gas meter (measuring device)
41 ... Flow sensor 42 ... Pressure sensor 47 ... Microcomputer (microcomputer unit)
48 ... Drive circuit 48a ... Simple measurement mode drive circuit 48b ... High-speed measurement mode drive circuit 48c ... Normal measurement mode drive circuit

Claims (7)

A flow rate sensor that outputs an electrical signal corresponding to the gas flow rate in the flow path;
A first process for measuring the gas flow rate in the flow path based on the electrical signal output from the flow rate sensor during the measurement time within the first predetermined time is performed, and the flow is performed based on the electrical signal from the flow rate sensor. A microcomputer unit that executes a second process for determining that the gas flow rate in the passage has changed every second predetermined time shorter than the measurement time;
The microcomputer unit is configured to execute in parallel the first process and the second process, an electric signal obtained from the measured time the flow rate sensor during the measurement of gas flow rate in the first processing, and, second A measuring device that is used for both gas flow rate change judgments in processing.
The microcomputer unit executes only the second process when the gas flow rate in the flow path does not exceed a predetermined value continuously several times in the first process when the first process and the second process are performed in parallel. The measuring apparatus according to claim 1, wherein: The microcomputer unit detects at least one of a gas flow rate and a gas pressure every third predetermined time, judges use of a gas appliance installed on the downstream side of the gas flow path, and whether or not a gas leak has occurred. The measuring apparatus according to claim 1, wherein a third process for determining whether or not is performed. When it is determined that the gas flow rate in the flow path has changed in the second process when the first process and the second process are performed in parallel, the microcomputer unit executes the third process for a specific time after the determination. The measurement apparatus according to claim 3, wherein after the execution, the first process and the second process are again executed in parallel. The microcomputer unit is obtained by obtaining at least one of the frequency and the amplitude of the waveform from the waveform obtained by detecting at least one of the gas flow rate and the gas pressure every third predetermined time during the execution of the third process. Based on the calculation result indicating the value or at least one of the frequency and amplitude of the waveform, it is a gas leak or the use of a gas appliance having a governor of the gas appliance, or the use of a gas appliance having no governor. It is judged whether it exists. The measuring device in any one of Claim 3 or Claim 4 characterized by the above-mentioned. The flow rate sensor is an ultrasonic sensor, and the microcomputer unit determines whether or not the gas in the flow path is based on whether or not the ultrasonic propagation time has changed compared to the past propagation time during the execution of the second process. It is judged whether flow volume changed. The measuring device given in any 1 paragraph of Claims 1-5 characterized by things. First processing for measuring the gas flow rate in the flow path based on the electrical signal output from the flow sensor during the measurement time within the first predetermined time, and gas in the flow path based on the electrical signal from the flow sensor and executes in parallel a second process of determining short every second predetermined time than the measurement time of the flow rate is changed, the electric signal obtained from the flow rate sensor during the measurement time, the first A measurement method characterized by being used for both measurement of gas flow rate in processing and determination of gas flow rate change in second processing.

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