JP2018185125A - Gas leakage detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas leakage detector capable of easily specifying gas leakage at a piping place that a maintenance worker hardly manages.SOLUTION: A detector 1 includes: a housing 10 covering a portion more than a half of an outer peripheral surface at an interval in a radial direction of a gas pipe 50, for a circumferential direction of the outer peripheral surface of the gas pipe 50; one or more wheels 11 rotatably attached to the housing 10; a motor 12 configured to rotationally drive the wheels 11; a pressing member 13 configured to press the wheels 11 to the gas pipe side; a gas detection unit 14 configured to detect gas leaked from the gas pipe 50; a gas leakage notification unit 15 configured to give a notification on gas leakage; and a control unit 19 configured to cause the gas leakage notification unit 15 to give the notification on gas leakage, based on a detection signal indicating that the gas detection unit 14 has detected gas.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas leak detection device.

  As described in Patent Document 1, in an air conditioner installed in a large facility such as a building, the piping installation route and structure are complicated such that the piping for circulating the refrigerant passes through the ceiling of each floor, Piping locations that are difficult for maintenance workers to access easily tend to occur.

JP 2010-19479 A

  In an air conditioner, refrigerant gas may leak at the joints of pipes due to deterioration over time. Further, when the refrigerant gas leaks, the heat conversion efficiency of the air conditioner decreases and the performance deteriorates, so it is necessary to deal with it faster. However, if a gas leak occurs at a pipe location that is difficult for maintenance workers or the like to access, it is difficult to specify the gas leak location and it is difficult to respond quickly to the gas leak.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a gas leak detection device that can easily identify a gas leak at a pipe location that is difficult for a maintenance worker or the like to access.

  The gas leak detection device according to the present invention is a gas leak detection device that can move outside the gas pipe along the extending direction of the gas pipe, with respect to the circumferential direction of the outer peripheral surface of the gas pipe. A housing that covers at least half of the outer peripheral surface with a gap in the radial direction of the gas pipe, one or more wheels rotatably attached to the housing, and the one or more wheels are driven to rotate. A wheel drive unit, a pressing member that presses the wheel against the gas pipe in a state where the radial direction of the wheel substantially matches the radial direction of the gas pipe, and gas detection that detects gas leaked from the gas pipe And a gas leak notifying unit for notifying the gas leak, and a control unit for notifying the gas leak notifying unit of the gas leak based on a detection signal indicating that the gas detecting unit has detected the gas.

  According to the present invention, the gas leak detection device can be moved along the gas pipe by rotating the wheel while one or more wheels are pressing the gas pipe. When the gas detection unit detects gas during the movement of the gas, the gas leak notification unit reports the gas leak. Therefore, whether or not there is a gas leak point in the space even if the gas leak detector is moved along the gas pipe even in a pipe point located in a narrow space that is difficult for a maintenance worker to reach. Can easily be determined, and it is easy to identify gas leaks in piping locations that are difficult for maintenance workers to access.

  In the present invention, when the control unit receives the detection signal, the control unit may control the wheel driving unit so as not to supply power to the one or more wheels.

  According to the above configuration, when the gas detection unit detects gas, the gas leak detection device stops. Therefore, the gas leak detection device can be stopped around the gas leak location, and the gas leak location can be easily identified.

  In the present invention, a paint discharge unit that discharges the fluorescent paint may be provided, and the control unit may cause the paint discharge unit to discharge the fluorescent paint when receiving the detection signal.

  Locations that are difficult for maintenance workers to access are often dim. In addition, a person other than the person who has found the gas leak point may repair the gas leak point. According to this configuration, the fluorescent paint can be applied around the gas leaking portion. Therefore, even when the gas leak location is dim, the gas leak location can be illuminated with fluorescence, and the gas leak location can be easily identified and repaired. Furthermore, when a person other than the person who has found the gas leak point repairs the gas leak point, the position of the gas leak point can be easily explained to the person who performs the repair or the like.

  Further, in the present invention, a pore closing substance discharge unit that discharges a substance capable of closing the hole formed in the gas pipe is provided, and when the control unit receives the detection signal, the hole closing substance discharge unit The substance may be discharged.

  According to the said structure, the substance which can block | close a hole can be discharged to the circumference | surroundings of the hole produced in the gas pipe, and it is easy to block a part or all of the said hole. Therefore, the emergency process which plugs the hole which arose in the gas pipe is attained.

  Moreover, in this invention, you may provide the display part which displays the movement distance of the said wheel.

  According to the said structure, the distance which the gas leak detection apparatus moved can be grasped | ascertained. Therefore, it is easy to specify the gas leak location accurately.

  In the present invention, the gas detection unit can detect a gas concentration, and the control unit has a maximum gas concentration based on a signal representing the gas concentration from the gas detection unit. A point may be specified as a gas leak point.

  According to the said structure, a gas leak location can be pinpointed correctly.

  According to the gas leak detection apparatus according to the present invention, it is easy to specify a gas leak at a pipe location that is difficult for a maintenance worker or the like to access.

It is a figure showing the gas leak detection apparatus which concerns on one Embodiment of this invention, (a) is a model when the gas leak detection apparatus attached to the gas pipe is seen from one side of the extension direction of a gas pipe It is a top view. Moreover, (b) is a partial enlarged sectional view of the pressing member of the gas leak detection device, and (c) is a schematic diagram for explaining an outline of a remote control included in the gas leak detection device. It is a control block diagram of a gas leak detection apparatus. It is a figure showing the relationship between the extension direction of piping containing a gas leak location, and the density | concentration of gas. It is a flowchart which shows an example of the operation | movement procedure of a gas leak detection apparatus.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, when a plurality of embodiments and modifications are included, it is assumed from the beginning that a new embodiment is constructed by appropriately combining those characteristic portions.

  FIG. 1 is a diagram showing a gas leak detection device (hereinafter simply referred to as a detection device) 1 according to an embodiment of the present invention. FIG. 1 (a) shows a detection device 1 attached to a gas pipe 50 as a gas pipe. It is a model top view when it sees from one side of the extending direction of 50. Moreover, (b) is a partial enlarged cross-sectional view of the pressing member 13 of the detection device 1, and (c) is a schematic diagram for explaining the outline of the remote controller 20 included in the detection device 1.

  As shown in FIG. 1, the detection device 1 includes a housing 10, four wheels 11, four motors 12 as an example of a wheel drive unit, a pressing member 13, a gas detection unit 14 that detects gas, and a gas leak notification unit. As an example, a sound output device 15, a power supply unit 16 composed of a secondary battery such as a lithium ion secondary battery, a dry cell, etc., a paint discharge unit 17 that discharges fluorescent paint, a rotation speed detection unit 18, a control unit 19, And a remote controller (hereinafter simply referred to as a remote controller) 20.

  The housing 10 has a substantially C-shaped shape in a plan view, and has a shape formed when a part in the circumferential direction is cut from a cylinder. The housing 10 is integrally formed of a shape memory alloy. Each wheel 11 includes an annular wheel made of a metal such as aluminum or a resin, and a rubber tire 25. The rubber tire 25 is fitted into the outer peripheral surface of the wheel. A through hole extending in the axial direction is provided at the center of the annular wheel.

  The motor 12 is a direct current motor. The output shaft 12a of the motor 12 is fixed to the through hole of the wheel by press fitting or the like, and the wheel 11 is rotated by the power of the motor 12. Each motor 12 is urged in one direction with respect to the housing 10 by the pressing member 13. Specifically, the pressing member 13 includes a biasing member 23 including a first cylindrical portion 21, a second cylindrical portion 22, and a spring. The 1st cylindrical part 21 and the 2nd cylindrical part 22 are comprised, for example with a metal material. One end portion of the first cylindrical portion 21 is joined to the outer surface of the motor 12 by welding or soldering, and the other end portion of the second cylindrical portion 22 is joined to the inner surface of the housing 10 by welding or soldering or the like.

  As shown in FIG. 1B, an annular flange portion 21a extending inward in the radial direction is provided at the end of the first tubular portion 21 opposite to the motor side, and the second tubular portion. A small-diameter portion 22b having an outer diameter smaller than that of the large-diameter portion 22a is provided in a predetermined range on the center side of the 22 in the axial direction. The large diameter portion 22a and the small diameter portion 22b are connected via step portions 22c and 22d extending in the radial direction. The small diameter portion 22b and the two step portions 22c and 22d define a recess 22e. The annular flange portion 21a of the first tubular portion 21 is fitted into the recess 22e. As a result, the relative movement in the axial direction of the first tubular portion 21 with respect to the second tubular portion 22 is between the position where the flange portion 21a abuts on the step portion 22c and the position where the flange portion 21a abuts on the step portion 22d. The first cylindrical portion 21 is not separable from the second cylindrical portion 22.

  Referring to FIG. 1A again, the urging member 23 is disposed inside the double cylinder structure constituted by the first and second cylindrical portions 21 and 22. One end of the urging member 23 is joined to the inner surface of the housing 10, and the other end of the urging member 23 is joined to the outer surface of the case of the motor 12. Since the first and second cylindrical portions 21 and 22 and the case of the motor 12 are rigid bodies, the extending direction of the output shaft 12a of the motor 12 and the housing 10 made of a shape memory alloy are not deformed. The radial direction of the wheel 11 can be matched with a desired direction. Therefore, it is possible to press the tire 25 against the gas pipe 50 in a state where the radial direction of the tire 25 of the wheel 11 substantially matches the radial direction of the gas pipe 50.

  In addition, in the state where the 2nd cylindrical part 22 extended most with respect to the 1st cylindrical part 21, you may make it the energizing member 23 become a natural length, or you may make it be in the compressed state. . In the example shown in FIG. 1A, the four wheels 11 are arranged at equal intervals in the circumferential direction of the outer peripheral surface of the gas pipe 50 with the detection device 1 attached to the gas pipe 50. However, in a state where the detection device is attached to the gas pipe, two or more wheels may be arranged with a space in the circumferential direction of the outer peripheral surface of the gas pipe, and only one wheel may be provided. . However, it is preferable that there are three or more wheels, and that the force in the radial direction from the three or more wheels can be uniformly applied to the gas pipe in the circumferential direction if they are positioned at equal intervals on the outer peripheral surface of the gas pipe. .

  In the example shown in FIG. 1 (a), the housing 10 covers 3/4 or more of the outer peripheral surface of the gas pipe 50 with respect to the circumferential direction of the gas pipe 50. It only needs to cover more than half of the gas pipe. Specifically, for example, in FIG. 1 (a), the length of the housing in the circumferential direction is from a location indicated by 80 to a location indicated by 81, so that the housing covers about half of the outer peripheral surface of the gas pipe 50, and the wheel Also, the two shown by 90 and 91 may be used.

  The gas detection part 14 can be comprised with the existing gas detection part, and detects the density | concentration of refrigerant gas, such as Freon gas. The gas detection unit 14 is attached to the inner surface of the housing 10. It is preferable that the detection surface 14a of the gas detection unit 14 is disposed so as to face the gas pipe 50 in the radial direction. The gas detection unit 14 outputs a signal representing the concentration of the refrigerant gas to the control unit 19.

  The sound output device 15 includes a small speaker with a built-in amplifier, for example, and vibrates the diaphragm with a control signal from the control unit 19 to output an alarm sound. The paint discharger 17 includes a case 30 and a piezoelectric element 31, and a part of the side wall of the case 30 is constituted by a diaphragm 30b. The case 30 extends radially inward from the inner surface of the housing 10, and the case 30 is filled with a fluorescent paint 39. A nozzle 30 a is provided on the distal end side of the case 30, and the nozzle 30 a faces the gas pipe 50 in the radial direction.

  The piezoelectric element 31 is fixed to the outer surface of the diaphragm 30b. When the control unit 19 performs control to supply power to the piezoelectric element 31, the diaphragm 30 b is displaced so as to reduce the volume of the case 30 as the piezoelectric element 31 is displaced, and the fluorescent paint 39 in the case 30. Is discharged from the nozzle 30a to the gas pipe 50. The housing 10 is provided with a paint filling passage 10a that communicates the inside and the outside of the case 30 and a cap 10b that opens and closes the outer opening of the paint filling passage 10a. The cap 10b is fixed to the housing 10 by being screwed into a female screw provided on the outside of the paint filling passage 10a, and seals the outer opening of the paint filling passage 10a. The fluorescent paint 39 is filled into the case 30 from the outside of the detection device 1 through the opening after the cap 10b is removed.

  As shown in FIG. 1C, the remote controller 20 includes operation units 20a to 20c and a display unit 20d. A maintenance worker or the like can wirelessly output a signal for rotating each motor 12 to one side by operating the operation unit 20a to the control unit 19, and a signal for rotating each motor 12 to the other side by operating the operation unit 20b. Can be output to the control unit 19 wirelessly. In addition, a maintenance worker or the like can wirelessly output a signal for stopping each motor 12 to the control unit 19 by operating the operation unit 20c.

  Referring to FIG. 1A again, the rotation speed detection unit 18 detects the rotation speed of the output shaft 12 a of the motor 12 and outputs a signal representing the rotation speed to the control unit 19. The control unit 19 calculates the distance traveled by the detection device 1 based on the rotation speed and the length of the outer peripheral surface of the tire 25, and causes the display unit 20d to display the distance wirelessly.

  FIG. 2 is a control block diagram of the detection apparatus 1. As shown in FIG. 2, signals are input to the control unit 19 wirelessly from the operation units 20 a to 20 c of the remote controller 20, and signals are also input from the gas detection unit 14 and the rotation speed detection unit 18. The control unit 19 controls the piezoelectric element 31, the motor 12, the sound output device 15, and the display unit 20d based on the input signal.

  The control unit 19 includes a CPU (Central Processing Unit) and a storage unit such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The CPU has a function of reading and executing a program or the like stored in advance in the storage unit. The RAM has a function of temporarily storing the read program and processing data. Further, the ROM has a function of previously storing a control program, a predetermined threshold value, and the like. The control unit 19 can be realized by software executed by a microcomputer, but a part thereof may be configured by hardware. Specific control of the control unit 19 will be described in detail later with reference to FIG.

  Next, a method for identifying a gas leak location of the detection device 1 will be described. As described above, the gas detection unit 14 can detect the gas concentration. Here, as shown in FIG. 3, the gas concentration is highest at the gas leakage point a1 with respect to the extending direction of the pipe (the moving direction of the detection device 1), and gradually decreases with distance from the gas leakage point a1. That is, the gas concentration is highest and maximizes at the gas leakage point a1. The control unit 19 specifies the maximum point of the gas concentration based on the signal representing the gas concentration from the gas detection unit 14, and specifies the maximum point as the gas leakage point. For example, the control unit 19 may identify a point where the gas concentration has decreased for the first time as a gas leak point.

  FIG. 4 is a flowchart illustrating an example of an operation procedure of the detection device 1. Next, an example of operation | movement of the detection apparatus 1 is demonstrated using FIG.

  When performing gas detection, first, a maintenance worker or the like pushes the gas pipe 50 in such a manner that the gap 26 (see FIG. 1A) of the shape memory alloy housing 10 of the detection device 1 is expanded. Then, through the gap 26, the four wheels 11 of the detection device 1 are pressed against the outer peripheral surface of the gas pipe 50, and the detection device 1 is attached to the outer peripheral surface of the gas pipe 50.

  Thereafter, when a maintenance worker or the like operates the operation unit 20 a of the remote controller 20, the control unit 19 rotates the output shaft 12 a of each motor 12 in one direction, and the detection device 1 follows the gas pipe 50. As described above, the electric power is supplied to the gas detection unit 14 and the gas detection of the gas detection unit 14 is started.

  When the movement of the detection device 1 and the gas detection of the gas detection unit 14 are started, in step S1, the control unit 19 determines whether the gas detection unit 14 has detected a gas. If a negative determination is made in step S1, the process proceeds to step S2. In step S <b> 2, based on the signal from the rotation speed detection unit 18, the control unit 19 determines whether or not the detection device 1 has reached a position where it cannot move any more.

  In other words, in step S <b> 2, the control unit 19 determines whether or not the detection device 1 is stopped based on the signal from the rotation speed detection unit 18. In the gas pipe 50, a floor having a large diameter is generally used at the joint of the pipe. Accordingly, when the detection device 1 reaches the floor or the like, it cannot be moved further forward. In step S <b> 2, based on the signal from the rotation speed detection unit 18, the detection device 1 determines whether or not it has reached a floor or the like having a large diameter and cannot be moved further forward. If an affirmative determination is made in step S2 and it is determined that the detection device 1 has reached a position where it cannot move any more, the operation is ended. On the other hand, if a negative determination is made in step S2 and it is determined that the detection apparatus 1 can move forward, steps S1 and after are repeated.

  On the other hand, if an affirmative determination is made in step S1 and it is determined that the gas detection unit 14 has detected a gas, the process proceeds to step S3. In step S <b> 3, the control unit 19 turns off the switching elements in the motor power supply circuit that supplies the electric power from the power supply unit 16 to each motor 12. In this way, power is not supplied to each motor 12 and the movement of the detection device 1 is stopped.

  When step S3 ends, the process proceeds to step S4. In step S4, the control unit 19 turns on the switching element in the power supply circuit for the sound output device that supplies power from the power supply unit 16 to the sound output device 15, and supplies power to the sound output device 15. The sound output device 15 is made to output an alarm sound.

  When step S4 ends, the process proceeds to step S5. In step S <b> 5, the control unit 19 turns on the switching element in the piezoelectric element power supply circuit that supplies power from the power supply unit 16 to the piezoelectric element 31 to supply power to the piezoelectric element 31. Is displaced. Due to this displacement, the diaphragm 30 b is displaced to the inside of the case, and the fluorescent paint is discharged from the nozzle 30 a of the paint discharge unit 17 toward the gas pipe 50. When step S5 ends, the operation ends.

  When the detection device 1 moves, the control unit 19 causes the display unit 20d to wirelessly display the movement distance of the detection device 1. Also, a maintenance worker or the like can reversely rotate each motor 12 by operating the operation unit 20b of the remote controller 20. As a result, a maintenance worker or the like can move the detection device 1 so as to move backward, and can easily take out the detection device 1 from a location that is difficult to access.

  According to the above embodiment, the detection device 1 can be moved along the gas pipe by rotating the wheel 11 in a state where the one or more wheels 11 are pressing the gas pipe 50. When the gas detector 14 detects gas while the device 1 is moving, the sound output device 15 outputs an alarm sound. Therefore, even in a piping place arranged in a narrow space that is difficult for a maintenance worker or the like to reach, it is determined whether or not there is a gas leaking place in the space just by moving the detection device 1 along the gas pipe. It is possible to easily identify a gas leak at a pipe location that is difficult for maintenance workers to access.

  Moreover, when the gas detection part 14 detects the gas which leaked from the gas pipe 50, the detection apparatus 1 will stop. Therefore, the detection apparatus 1 can be stopped around the gas leak location, and the gas leak location can be easily identified.

  In addition, portions that are difficult for maintenance workers to access are often dim. Furthermore, a person different from the person who has found the gas leak point may repair the gas leak point. According to the said embodiment, a fluorescent paint can be apply | coated around a gas leak location. Therefore, even when the gas leak location is dim, the gas leak location can be illuminated with fluorescence, and it is easy to identify and repair the gas leak location. Furthermore, when a person other than the person who has found the gas leak point repairs the gas leak point, the position of the gas leak point can be easily explained to the person who performs the repair or the like.

  Moreover, since it has the display part 20d which displays the moving distance of the wheel 11, it becomes easy for a maintenance worker etc. to pinpoint a gas leak location correctly. Furthermore, since the control part 19 specifies the point where gas concentration becomes the maximum as a gas leak point based on the signal showing the gas concentration from the gas detection part 14, a gas leak point can be specified correctly.

  The present invention is not limited to the above-described embodiment and its modifications, and various improvements and modifications can be made within the matters described in the claims of the present application and their equivalent ranges.

  For example, in the above embodiment, the case where the control unit 19 outputs an alarm sound to the sound output device 15 when the gas detection unit 14 detects gas has been described. However, when the gas detection unit detects gas, the control unit may notify the gas leakage by emitting light to the light emitting unit instead of outputting the alarm sound to the sound output device. In addition to outputting sound, the light leakage may be notified by emitting light to the light emitting unit.

  Moreover, when the gas detection part 14 detected gas, after the control part 19 stopped the detection apparatus 1, the case where fluorescent paint was discharged to the gas pipe 50 from the paint discharge part 17 was demonstrated. However, the detection apparatus includes a substance capable of closing the hole formed in the gas pipe, for example, a hole closing substance discharging unit that discharges a fluid resin that is heated by an adhesive, a heater, or the like, When the gas detection unit detects gas, the control unit may cause the pore closing material discharge unit to discharge the substance. In this way, an emergency process for closing at least a part of the hole formed in the gas pipe may be made possible.

  Moreover, the case where the control part 19 specified the location where gas concentration became the maximum as a gas leak location was demonstrated. However, if the gas concentration gradually increases as it approaches the location where the detection device can no longer go forward (location where flares, etc.), the control section You may determine with a gas leak location.

  Alternatively, the control unit may specify a location where the gas detection unit has detected gas for the first time as a gas leakage location, stop the detection device at that location, and cause the notification unit to notify the gas leakage at that location. . In this case, the gas detection unit may not be able to detect the gas concentration, and may be configured to detect only the presence or absence of the gas.

  Further, the case where the wheel drive unit is the motor 12 has been described. However, the vehicle drive unit may include a spring having one end fixed to the housing and a string having one end attached to the other end of the spring. Then, the spring may be extended by pulling the string, and the wheel may be rotated by the restoring force of the spring. May be.

  Further, the case where the housing 10 is made of a deformable shape memory alloy, the housing 10 is deformed so as to widen the gap 26, and the detection device 1 is attached to the gas pipe 50 has been described. However, the housing may have the same structure as the clothespins or handcuffs, and can be configured to select an annular structure or a non-annular structure. And when attaching a detection apparatus to a gas pipe, after making a housing into a non-annular structure and letting an opening of a non-annular structure pass a gas pipe, a housing may be made into a ring structure. In this manner, the housing may surround the entire circumference of the gas pipe with the detection device attached to the gas pipe.

  Moreover, although the case where the detection apparatus 1 includes the paint discharge unit 17 has been described, the detection apparatus may not include the paint discharge unit. Moreover, although the case where the detection device 1 includes the display unit 20d that displays the movement distance of the detection device 1 has been described, the detection device may not include the display unit. Moreover, although the case where gas was refrigerant gas of an air conditioner was demonstrated, city gas and propane gas may be sufficient as gas.

  DESCRIPTION OF SYMBOLS 1 Gas leak detection apparatus, 10 Housing, 11 Wheel, 12 Motor, 13 Press member, 14 Gas detection part, 15 Sound output device, 17 Paint discharge part, 19 Control part, 20d Display part, 50 Gas pipe

Claims (6)

A gas leak detection device capable of moving outside the gas pipe along the extending direction of the gas pipe,
With respect to the circumferential direction of the outer peripheral surface of the gas pipe, a housing that covers at least half of the outer peripheral surface with a gap in the radial direction of the gas pipe;
One or more wheels rotatably attached to the housing;
A wheel drive unit that rotationally drives the one or more wheels;
A pressing member that presses the wheel against the gas pipe in a state where the radial direction of the wheel substantially coincides with the radial direction of the gas pipe;
A gas detector for detecting gas leaked from the gas pipe;
A gas leak notification unit for notifying gas leak;
A control unit that informs the gas leakage notification unit of gas leakage based on a detection signal indicating that the gas detection unit has detected the gas;
A gas leak detection device comprising: In the gas leak detection device according to claim 1,
When the control unit receives the detection signal, the control unit controls the wheel drive unit so as not to supply power to the one or more wheels. In the gas leak detection device according to claim 2,
It has a paint discharge part that discharges fluorescent paint,
A gas leak detection device that causes the paint discharge unit to discharge the fluorescent paint when the control unit receives the detection signal. In the gas leak detection device according to claim 2 or 3,
A hole closing substance discharge section for discharging a substance capable of closing the hole generated in the gas pipe;
The gas leak detection device, which, when the control unit receives the detection signal, causes the pore closing material discharge unit to discharge the substance. In the gas leak detection device according to any one of claims 1 to 4,
A gas leak detection apparatus comprising a display unit for displaying a moving distance of the wheel. In the gas leak detection device according to any one of claims 1 to 5,
The gas detection unit is capable of detecting a gas concentration,
The said control part is a gas leak detection apparatus which specifies the point where the density | concentration of the said gas becomes the maximum as a gas leak point based on the signal showing the density | concentration of the said gas from the said gas detection part.

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