JP2021067631A - Method of measuring gas concentration in packaging bag - Google Patents

Method of measuring gas concentration in packaging bag Download PDF

Info

Publication number
JP2021067631A
JP2021067631A JP2019195094A JP2019195094A JP2021067631A JP 2021067631 A JP2021067631 A JP 2021067631A JP 2019195094 A JP2019195094 A JP 2019195094A JP 2019195094 A JP2019195094 A JP 2019195094A JP 2021067631 A JP2021067631 A JP 2021067631A
Authority
JP
Japan
Prior art keywords
laser
packaging bag
gas
gas concentration
reflecting surface
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2019195094A
Other languages
Japanese (ja)
Inventor
雅志 大島
Masashi Oshima
雅志 大島
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Packer Co Ltd
Original Assignee
General Packer Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Packer Co Ltd filed Critical General Packer Co Ltd
Priority to JP2019195094A priority Critical patent/JP2021067631A/en
Publication of JP2021067631A publication Critical patent/JP2021067631A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

To provide a gas concentration measurement method which improves measurement accuracy by increasing the optical path length of a laser beam to a fixed length.SOLUTION: A gas concentration measurement method using a laser-type gas concentration meter is provided, the method comprising letting a laser beam of a specific wavelength pass through a gas-replaced, sealed packaging bag B, and measuring gas concentration of a specific gas remaining in the packaging bag based on an absorption spectrum of the specific wavelength that changes before and after passing through the packaging bag, the laser-type gas concentration meter comprising a laser generator 11 for emitting the laser beam, a laser receiver 12 for receiving the laser beam, and reflective surfaces 30, 31 capable of reflecting the laser beam, where the laser beam that is emitted from the laser generator and passes through the packaging bag B is reflected multiple times by the reflective surfaces 30, 31 before being incident on the laser receiver.SELECTED DRAWING: Figure 1

Description

本発明は、ガス置換されて密封された包装袋内に残存する特定ガスのガス濃度を測定するガス濃度測定方法に関するものである。 The present invention relates to a gas concentration measuring method for measuring the gas concentration of a specific gas remaining in a package bag that has been gas-replaced and sealed.

従来、包装工程において、被包装物の保存期間又は賞味期間を縮めるおそれのある特定の酸化原因ガスを含んだ包装袋内の空気を除去して、不活性ガス、たとえば窒素、二酸化炭素等にガス置換してから密封するガス置換包装が行われている。これによって、包装袋内部の酸化原因ガスは除去され、被包装物、特に食品は、長期の保存期間、賞味期間を確保することができる。
そして、ガス置換包装後の検査工程において、酸化原因ガス、特に酸素の濃度が既定値以下であるかどうか検査が行われている。
しかしながら、現在主流である酸素濃度の測定方法は、サンプルとして任意に選択した包装袋に注射針を刺し、包装袋内から吸引した少量のガスの組成を検査する抜き取り検査である。当該抜き取り検査では、注射痕が形成された包装袋は廃棄しなければならない。また、検査精度を上げるためにサンプル数を増やすと検査時間が長くなり、増加する廃棄量によって経済的、時間的損失が増大する不都合があった。 Conventionally, in the packaging process, the air in the packaging bag containing a specific oxidation-causing gas that may shorten the storage period or the taste period of the packaged object is removed, and the gas is converted into an inert gas such as nitrogen or carbon dioxide. Gas replacement packaging is performed after replacement and sealing. As a result, the oxidation-causing gas inside the packaging bag is removed, and the packaged object, particularly the food, can secure a long storage period and a shelf life.
Then, in the inspection step after gas replacement packaging, inspection is performed to see if the concentration of the oxidation-causing gas, particularly oxygen, is equal to or less than the predetermined value.
However, the current mainstream method for measuring oxygen concentration is a sampling test in which an injection needle is inserted into a packaging bag arbitrarily selected as a sample and the composition of a small amount of gas sucked from the packaging bag is inspected. In the sampling inspection, the packaging bag on which the injection mark is formed must be discarded. Further, if the number of samples is increased in order to improve the inspection accuracy, the inspection time becomes long, and there is a disadvantage that the economic and time loss increases due to the increased amount of waste.

これに対し、本願出願人は、包装袋を損傷することなく内部の特定ガスの濃度を測定可能なガス濃度測定装置を開発した。
特開２０１０−１０７１９７に開示されている包装袋のガス濃度測定装置１は、図７に示すように、発信器を有するレーザー発生部２と、当該レーザー発生部２に連接し、レーザー光が射出される主ヘッド３、並びに受信器を有するレーザー受光部４と、当該レーザ受光部４に連接し、レーザー光が入射される副ヘッド５とからなる。相対的に接近及び離隔自在に設けられた主ヘッド３と副ヘッド５は、、一対のグリップ６，６に把持された検査対象の包装袋Ｂを挟んで、主ヘッド３に対して副ヘッド５が正対するように配置されている。これによって、主ヘッド３から副ヘッド５へ最短距離でレーザー光が包装袋を透過することができ、包装袋内に残留している酸素等の特定ガスの濃度を測定する際に、包装袋の全数について当該包装袋を一切損傷することなく迅速に測定することができるようになった。 On the other hand, the applicant of the present application has developed a gas concentration measuring device capable of measuring the concentration of a specific gas inside without damaging the packaging bag.
As shown in FIG. 7, the packaging bag gas concentration measuring device 1 disclosed in Japanese Patent Application Laid-Open No. 2010-107197 is connected to a laser generating unit 2 having a transmitter and the laser generating unit 2, and a laser beam is emitted. It is composed of a main head 3 to be generated, a laser light receiving unit 4 having a receiver, and a sub head 5 which is connected to the laser light receiving unit 4 and receives laser light. The main head 3 and the sub-head 5 provided so as to be relatively close to each other and separated from each other sandwich the packaging bag B to be inspected held by the pair of grips 6 and 6, and the sub-head 5 is relative to the main head 3. Are arranged so that they face each other. As a result, the laser beam can pass through the packaging bag from the main head 3 to the sub head 5 at the shortest distance, and when measuring the concentration of a specific gas such as oxygen remaining in the packaging bag, the packaging bag It has become possible to quickly measure all of the packaging bags without damaging the packaging bags.

特開２０１０−１０７１９７号公報JP-A-2010-107197

しかしながら、上記のガス濃度測定装置１は、包装袋Ｂに対してレーザー光を透過させるとき、包装袋Ｂ内に封じられる気体の量が多少変化しても光路長の変化が小さくなるように主ヘッド３と副ヘッド５を正対させて、光路長を一定にしている。これが、測定対象の包装袋Ｂ内の気体の状態を検査するために十分な光路長を確保することの妨げとなり、上記のガス濃度測定装置１は、測定対象である特定ガスのガス濃度について測定誤差が生じやすい状態であった。 However, in the gas concentration measuring device 1 described above, when the laser beam is transmitted through the packaging bag B, the change in the optical path length is mainly reduced even if the amount of gas sealed in the packaging bag B changes slightly. The head 3 and the sub head 5 face each other to keep the optical path length constant. This hinders securing a sufficient optical path length for inspecting the state of the gas in the packaging bag B to be measured, and the gas concentration measuring device 1 described above measures the gas concentration of the specific gas to be measured. It was in a state where errors were likely to occur.

したがって、本発明が解決しようとする課題は、レーザー光の光路長を長く伸ばすと共に当該光路長が一定になるようにして、測定精度を向上させたガス濃度測定方法を提供することである。 Therefore, an object to be solved by the present invention is to provide a gas concentration measuring method in which the optical path length of the laser beam is extended and the optical path length is kept constant to improve the measurement accuracy.

請求項１に記載のガス濃度測定方法は、特定波長のレーザー光を、ガス置換されて密封された包装袋に透過させて、前記包装袋の透過前後で変化する特定波長の吸収スペクトルに基づいて前記包装袋の内部に残留している特定ガスのガス濃度を測定するようにしたレーザー式ガス濃度計を有するガス濃度測定方法であって、
前記レーザー光を射出するレーザー発生部と、
前記レーザー光を受光するレーザー受光部と、
前記レーザー光が反射可能な反射面を有し、
前記レーザー発生部から射出され、前記包装袋を透過するレーザー光が、前記反射面で反射した後に前記レーザー受光部に入射するようにしたことを特徴とする。 The gas concentration measuring method according to claim 1 is based on an absorption spectrum of a specific wavelength that changes before and after transmission of the packaging bag by transmitting a laser beam of a specific wavelength through a package bag that has been gas-substituted and sealed. A gas concentration measuring method having a laser gas densitometer for measuring the gas concentration of a specific gas remaining inside the packaging bag.
The laser generating part that emits the laser light and
A laser receiving unit that receives the laser light and
It has a reflective surface on which the laser beam can be reflected, and has a reflective surface.
The laser light emitted from the laser generating portion and transmitted through the packaging bag is reflected by the reflecting surface and then incident on the laser receiving portion.

請求項２に記載のガス濃度測定方法は、請求項１に記載の発明において、前記反射面が、前記包装袋を挟んで互いに平行に対向した第１反射面と第２反射面からなり、
前記レーザー光が、前記第１反射面と前記第２反射面との間で複数回反射するようにしたことを特徴とする。 The gas concentration measuring method according to claim 2 comprises the invention according to claim 1, wherein the reflective surface comprises a first reflective surface and a second reflective surface that face each other in parallel with the packaging bag in between.
The laser light is reflected a plurality of times between the first reflecting surface and the second reflecting surface.

本発明に係るガス濃度測定方法によれば、レーザー発生部から射出されたレーザー光が包装袋を透過するとき、反射面で反射した後にレーザー受光部に入射するようにした。これによって、レーザー光の光路長を伸ばすことができるので、ガス濃度を測定するときの測定精度を向上させることができる。
また好ましくは、反射面が包装袋を挟んで互いに平行に対向する第１反射面と第２反射面からなるように構成し、第１反射面と第２反射面との間でレーザー光を複数回、すなわち少なくとも２回は反射させるようにした。これによって、レーザー発生部とレーザー受光部とを同一側に配置してレーザー光を奇数回、少なくとも１回反射させるよりも一回多く偶数回反射させることができるので、より一層光路長を延長することができる。 According to the gas concentration measuring method according to the present invention, when the laser light emitted from the laser generating portion passes through the packaging bag, it is reflected by the reflecting surface and then incident on the laser receiving portion. As a result, the optical path length of the laser beam can be extended, so that the measurement accuracy when measuring the gas concentration can be improved.
Further, it is preferable that the reflecting surfaces are composed of a first reflecting surface and a second reflecting surface which face each other in parallel with the packaging bag sandwiched between them, and a plurality of laser beams are emitted between the first reflecting surface and the second reflecting surface. It was made to reflect once, that is, at least twice. As a result, the laser generating unit and the laser receiving unit can be arranged on the same side to reflect the laser light an odd number of times, at least once, and even-numbered times more than once, so that the optical path length can be further extended. be able to.

第１実施例に係るガス濃度測定方法に用いるガス濃度測定装置の構成の概略を示す平面図である。It is a top view which shows the outline of the structure of the gas concentration measuring apparatus used in the gas concentration measuring method which concerns on 1st Example. 第１実施例に係るガス濃度測定方法に用いるガス濃度測定装置の構成の概略を示すブロック図である。It is a block diagram which shows the outline of the structure of the gas concentration measuring apparatus used in the gas concentration measuring method which concerns on 1st Example. 第１実施例に係るガス濃度測定方法の原理を説明する説明図である。It is explanatory drawing explaining the principle of the gas concentration measurement method which concerns on 1st Example. 第１実施例に係るガス濃度測定方法に用いるガス濃度測定装置の第１反射パターンの構成の概略を示す横断面図である。It is a cross-sectional view which shows the outline of the structure of the 1st reflection pattern of the gas concentration measuring apparatus used in the gas concentration measuring method which concerns on 1st Example. 第１実施例に係るガス濃度測定方法に用いるガス濃度測定装置の第２反射パターンの構成の概略を示す縦断面図である。It is a vertical cross-sectional view which shows the outline of the structure of the 2nd reflection pattern of the gas concentration measuring apparatus used in the gas concentration measuring method which concerns on 1st Example. 第１実施例に係るガス濃度測定方法に用いるガス濃度測定装置の第３反射パターンの構成の概略を示す斜視図である。It is a perspective view which shows the outline of the structure of the 3rd reflection pattern of the gas concentration measuring apparatus used in the gas concentration measuring method which concerns on 1st Example. 従来のガス濃度測定装置の構成の概略を示す平面図である。It is a top view which shows the outline of the structure of the conventional gas concentration measuring apparatus.

本発明に係るガス濃度測定方法の実施例を、添付した図面にしたがって説明する。
図１は本実施例に係るガス濃度測定方法に用いるガス濃度測定装置の構成の概略を示す平面図であり、図２は当該ガス濃度測定装置の構成の概略を示すブロック図である。 Examples of the gas concentration measuring method according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a plan view showing an outline of the configuration of a gas concentration measuring device used in the gas concentration measuring method according to the present embodiment, and FIG. 2 is a block diagram showing an outline of the configuration of the gas concentration measuring device.

本実施例に係るガス濃度測定方法は、包装袋の内部に残留している特定ガスのガス濃度を測定する方法である。当該ガス濃度測定方法は、出荷前に包装袋を検査する検査場で行われたり、また、包装に係る各種工程を有するロータリー式或いはピロー式等の包装機の検査工程で行われている。本実施例においては、それらを踏まえて、ガス濃度測定方法に絞って説明する。
残留している特定ガスとは、たとえば、酸素ガス（Ｏ２）である。大気雰囲気下で行われる包装機の包装工程では、被包装物を充填したとき、包装袋内部に大気も充填される。大気に含まれている酸素ガスをはじめとした酸化原因ガスは、被包装物、特に食品類を酸化させて劣化させる原因となる。そのため、包装機には、被包装物を包装袋に充填する包装工程の後に、当該包装袋から大気を抜気して、不活性ガス、たとえば、窒素ガス（Ｎ２）、二酸化炭素ガス（ＣＯ２）へ置き換えるガス置換（ガスパージ）工程が設けられている。
その後、ガス置換された包装袋内部の酸素ガスのガス濃度を測定して、当該酸素ガスのガス濃度が基準値以下に収まっているかどうか検査する方法が、本実施例に係るガス濃度測定方法である。酸素ガスのガス濃度を測定したとき、ガス濃度が基準値以下に収まっている場合は、正常にガス置換が行われ、包装袋内部は不活性ガスが充満しているので、被包装物の酸化を防止することができ、保存期間や賞味期間を延ばすことができる。対して、ガス濃度が基準値を超えている場合は、不良品と判断されて、たとえば、包装機の包装工程から排出されるように構成されている。 The gas concentration measuring method according to this embodiment is a method for measuring the gas concentration of a specific gas remaining inside the packaging bag. The gas concentration measuring method is performed at an inspection site that inspects packaging bags before shipment, or is performed in an inspection process of a rotary type or pillow type packaging machine that has various processes related to packaging. In this embodiment, based on these, the gas concentration measuring method will be focused on.
The residual specific gas is, for example, oxygen gas (O 2 ). In the packaging process of a packaging machine performed in an air atmosphere, when the object to be packaged is filled, the inside of the packaging bag is also filled with air. Oxidation-causing gases such as oxygen gas contained in the atmosphere cause oxidation and deterioration of the packaged material, especially foods. Therefore, in the packaging machine, after the packaging process of filling the packaging bag with the object to be packaged, the air is evacuated from the packaging bag, and an inert gas such as nitrogen gas (N 2 ) or carbon dioxide gas (CO) is used. A gas replacement (gas purge) step for replacing with 2) is provided.
After that, the method of measuring the gas concentration of the oxygen gas inside the gas-replaced packaging bag and inspecting whether the gas concentration of the oxygen gas is within the reference value is the gas concentration measuring method according to the present embodiment. is there. When the gas concentration of oxygen gas is measured, if the gas concentration is below the standard value, gas replacement is performed normally and the inside of the packaging bag is filled with inert gas, so oxidation of the packaged object is performed. Can be prevented, and the storage period and the best-before date can be extended. On the other hand, if the gas concentration exceeds the standard value, it is determined to be a defective product, and for example, it is configured to be discharged from the packaging process of the packaging machine.

本実施例に係るガス濃度測定法に用いられるガス濃度測定装置は、図１に示すように、レーザー光を射出するレーザー発生部１１と、レーザー光を受光するレーザー受光部１２とを備えたレーザー式ガス濃度計と、レーザー光を反射する反射面を有している。さらに、測定対象の包装袋は、袋口両端を一対のグリップ６，６で把持されている。 As shown in FIG. 1, the gas concentration measuring device used in the gas concentration measuring method according to the present embodiment is a laser including a laser generating unit 11 that emits laser light and a laser receiving unit 12 that receives laser light. It has a type gas densitometer and a reflecting surface that reflects laser light. Further, the packaging bag to be measured has both ends of the bag mouth gripped by a pair of grips 6 and 6.

レーザー式ガス濃度計は、波長可変半導体レーザー吸収分光法によって特定ガスを分析可能に形成されている。
ここで、波長可変半導体レーザー吸収分光法（Ｔｕｎａｂｌｅ Ｄｉｏｄｅ Ｌａｓｅｒ Ａｂｓｏｒｐｔｉｏｎ Ｓｐｅｃｔｒｏｓｃｏｐｙ：ＴＤＬＡＳ）とは、半導体レーザー素子から出力されたレーザー光に係る所定の入射光強度と、測定対象となる特定ガス含んだ気体を封じたセルを透過して、当該特定ガスに吸収された透過後のレーザー光に係る透過光強度とから透過率を求めて、透過率に基づくレーザー光の吸光度からガス濃度を測定する方法である。
特定ガスを含めて気体はそれぞれ固有の吸収波長帯を有し、当該吸収波長帯にはより強く光を吸収する波長に係る吸収線が複数本含まれていることが知られている。ＴＤＬＡＳは、出力するレーザー光の近赤外領域の波長を、測定対象となる特定ガスの複数本の吸収線のうち、一本の吸収線に係る特定波長に合致するように変調し、増幅するように構成されている。そして、セルの透過前後で変化する特定波長の吸収スペクトルに基づいてレーザー光の吸光度を求めてガス濃度を測定している。なお、本実施例において測定対象ガスは酸素ガスであって、当該測定対象ガスを封じるセルは包装袋である。 The laser gas densitometer is formed so that a specific gas can be analyzed by tunable semiconductor laser absorption spectroscopy.
Here, the wavelength variable semiconductor laser absorption spectrometry (TDLAS) is a predetermined incident light intensity related to the laser light output from the semiconductor laser element and a gas containing a specific gas to be measured. This is a method in which the transmittance is obtained from the transmitted light intensity of the transmitted laser light absorbed by the specific gas after passing through the sealed cell, and the gas concentration is measured from the absorbance of the laser light based on the transmittance. ..
It is known that each gas including a specific gas has a unique absorption wavelength band, and the absorption wavelength band includes a plurality of absorption lines related to wavelengths that absorb light more strongly. TDLAS modulates and amplifies the wavelength of the output laser light in the near-infrared region so as to match the specific wavelength of one absorption line among the plurality of absorption lines of the specific gas to be measured. It is configured as follows. Then, the gas concentration is measured by obtaining the absorbance of the laser beam based on the absorption spectrum of a specific wavelength that changes before and after the transmission of the cell. In this embodiment, the gas to be measured is oxygen gas, and the cell that seals the gas to be measured is a packaging bag.

レーザー発生部１１は、図２に示すように、レーザー光源１３と、当該光源から射出するレーザー光の波長を特定の波長に設定し、所定の光強度に調整する制御部１４とを有している。
レーザー光源１３は、波長が可変可能なダイオードからなる半導体レーザー素子を備え、近赤外領域のレーザー光を出力可能に形成されている。
制御部１４は、半導体レーザー素子から出力されるレーザー光の波長を測定対象の特定ガス固有の特定波長に調整して、レーザー光が所定の入射光強度で射出されるように増幅する制御を行うように形成されている。
ここで、本実施例に係るレーザー式ガス濃度計が測定する特定ガスは、酸素ガスである。当該酸素ガス固有の吸収波長帯は７６０ｎｍ帯であり、当該吸収波長帯に含まれる複数の吸収線のうち、一の吸収線に係る特定波長がレーザー光の出力波長として選択される。 As shown in FIG. 2, the laser generation unit 11 includes a laser light source 13 and a control unit 14 that sets the wavelength of the laser light emitted from the light source to a specific wavelength and adjusts the wavelength to a predetermined light intensity. There is.
The laser light source 13 includes a semiconductor laser element made of a diode having a variable wavelength, and is formed so as to be capable of outputting laser light in the near infrared region.
The control unit 14 adjusts the wavelength of the laser light output from the semiconductor laser element to a specific wavelength peculiar to the specific gas to be measured, and controls to amplify the laser light so that it is emitted at a predetermined incident light intensity. It is formed like this.
Here, the specific gas measured by the laser gas densitometer according to the present embodiment is oxygen gas. The absorption wavelength band peculiar to the oxygen gas is the 760 nm band, and among the plurality of absorption lines included in the absorption wavelength band, a specific wavelength related to one absorption line is selected as the output wavelength of the laser beam.

レーザー発生部１１は、第１ハウジング１５に内蔵されている。当該第１ハウジング１５は第１窓部１６を有している。第１窓部１６には、近赤外領域の光を通しやすいサファイヤガラスが嵌め込まれている。そして、レーザー発生部１１は、第１窓部１６を通じて第１ハウジング１５からレーザー光を射出するように形成されている。 The laser generator 11 is built in the first housing 15. The first housing 15 has a first window portion 16. A sapphire glass that easily allows light in the near infrared region to pass through is fitted in the first window portion 16. The laser generating portion 11 is formed so as to emit laser light from the first housing 15 through the first window portion 16.

第１ハウジング１５内は特定ガス、本実施例においては酸素ガスを除去するために、真空化またはガス置換（ガスパージ）をすることができるように形成されている。そのため、第１ハウジング１５内を真空で維持したり、或いは窒素ガス、又は二酸化炭素或いはこれらに類する不活性ガス類で満たすことができる。
これによって、レーザー光源１３から第１窓部１６を通じて射出するまでの間に、第１ハウジング１５内でレーザ光が特定ガスに吸収されることを防止することができるので、ガス濃度測定の精度を向上させることができる。 The inside of the first housing 15 is formed so that vacuuming or gas replacement (gas purging) can be performed in order to remove a specific gas, or oxygen gas in this embodiment. Therefore, the inside of the first housing 15 can be maintained in a vacuum, or can be filled with nitrogen gas, carbon dioxide, or an inert gas similar thereto.
As a result, it is possible to prevent the laser beam from being absorbed by the specific gas in the first housing 15 during the period from the laser light source 13 to the emission through the first window portion 16, so that the accuracy of gas concentration measurement can be improved. Can be improved.

レーザー受光部１２は、図２に示すように、包装袋を透過したレーザー光を受光する受光センサ２０と、当該受光センサ２０からの受光信号に基づいて、ガス濃度を測定する測定部２１とを有している。
受光センサ２０は、包装袋を透過したレーザー光の透過光強度を電気的な透過光信号に変換する素子、たとえば、フォトダイオードからなる。これによって、包装袋を透過したレーザー光の透過光強度を電気的に処理することができる。
測定部２１は、透過光強度に係る透過光信号と、レーザー発生部１１から出力されたレーザー光の入射光強度に係る入射光信号に基づいて透過率を計算し、当該透過率に基づいてレーザー光の特定ガスによる吸光度を求め、当該吸光度に基づいて包装袋内の特定ガスの濃度を測定するように形成されている。 As shown in FIG. 2, the laser light receiving unit 12 includes a light receiving sensor 20 that receives the laser light transmitted through the packaging bag and a measuring unit 21 that measures the gas concentration based on the light receiving signal from the light receiving sensor 20. Have.
The light receiving sensor 20 includes an element that converts the transmitted light intensity of the laser light transmitted through the packaging bag into an electrically transmitted light signal, for example, a photodiode. Thereby, the transmitted light intensity of the laser light transmitted through the packaging bag can be electrically processed.
The measuring unit 21 calculates the transmittance based on the transmitted light signal related to the transmitted light intensity and the incident light signal related to the incident light intensity of the laser light output from the laser generating unit 11, and the laser is based on the transmittance. It is formed so as to determine the absorbance of light by a specific gas and measure the concentration of the specific gas in the packaging bag based on the absorbance.

レーザー受光部１２は、第２ハウジング２２に内蔵されている。第２ハウジング２２は第２窓部２３を有している。第２窓部２３には、第１窓部１６と同様に、近赤外領域の光を通しやすいサファイヤガラスが嵌め込まれている。
これによって、レーザー受光部１２は、第２窓部２３を通じて包装袋を透過したレーザー光を受光するように形成されている。
第２ハウジング２２内もまた、第１ハウジングと同様に、真空化又は、ガス置換可能に形成されている。そのため、第２窓部２３を通じて入射されたレーザー光を受光センサ２０が受光するまでの間に、第２ハウジング２２内でレーザ光が特定ガスに吸収されることを防止することができるので、ガス濃度測定の精度を向上させることができる。 The laser light receiving unit 12 is built in the second housing 22. The second housing 22 has a second window portion 23. Similar to the first window portion 16, the second window portion 23 is fitted with sapphire glass that easily allows light in the near infrared region to pass through.
As a result, the laser light receiving portion 12 is formed so as to receive the laser light transmitted through the packaging bag through the second window portion 23.
The inside of the second housing 22 is also formed so as to be evacuated or gas-replaceable like the first housing. Therefore, it is possible to prevent the laser beam from being absorbed by the specific gas in the second housing 22 until the light receiving sensor 20 receives the laser beam incident through the second window portion 23. The accuracy of concentration measurement can be improved.

このように、レーザー式ガス濃度計は、図１及び図２に示すように、レーザー発生部１１から第１窓部１６を通じてレーザー光を射出し、当該レーザー光を測定対象の包装袋Ｂに透過させて、第２窓部２３を通じてレーザー受光部１２で包装袋Ｂを透過したレーザー光を受光するように構成されている。
そして、当該レーザー式ガス濃度計を有するガス濃度測定装置１０は、第１窓部１６から射出されたレーザー光を第２窓部２３へ入射させる間に、反射面で少なくとも一回、好ましくは複数回反射させるように構成されている。 As described above, as shown in FIGS. 1 and 2, the laser gas densitometer emits laser light from the laser generating unit 11 through the first window unit 16 and transmits the laser light to the packaging bag B to be measured. The laser light receiving unit 12 is configured to receive the laser light transmitted through the packaging bag B through the second window unit 23.
Then, the gas concentration measuring device 10 having the laser type gas densitometer has at least once, preferably a plurality of laser beams emitted from the first window portion 16 while incidenting the laser light emitted from the first window portion 16 onto the second window portion 23. It is configured to reflect times.

反射面は、所定の位置に第１窓部１６が設けられた第１反射面３０と、所定の位置に第２窓部２３が設けられた第２反射面３１とからなり、第１反射面３０と第２反射面３１は、互いに平行に対向するように設けられている。反射面３０，３１は、たとえば、鏡面、又は鏡面状に磨き上げられた金属、或いは所定の基材に鏡面状の膜体を貼り付けものからなり、レーザー光を反射可能に形成されている。 The reflecting surface is composed of a first reflecting surface 30 having a first window portion 16 provided at a predetermined position and a second reflecting surface 31 provided with a second window portion 23 at a predetermined position, and is composed of a first reflecting surface. The 30 and the second reflecting surface 31 are provided so as to face each other in parallel. The reflecting surfaces 30 and 31 are made of, for example, a mirror surface, a metal polished to a mirror surface shape, or a mirror surface film body attached to a predetermined base material, and are formed so as to be able to reflect laser light.

第１反射面３０と第２反射面３１は、相対的に接離自在に形成され、図１に示すように、第１反射面３０と第２反射面３１との間に包装袋Ｂを挟持可能に形成されている。そのため、第１反射面３０と第２反射面３１で包装袋Ｂを挟持したとき、包装袋Ｂに第１反射面３０と第２反射面３１を密着させることができる。
さらに、包装袋Ｂに対する第１窓部１６と第２窓部２３の位置を定めることによって、第１反射面３０と第２反射面３１で包装袋Ｂを挟持したとき、包装袋Ｂに第１窓部１６と第２窓部２３も密着させることができる。
これによって、レーザー光を第１窓部１６から射出して、第２反射面３１、第１反射面３０と反射させて、第２窓部２３へ入射させるとき、大気に含まれている特定ガスの影響を最小限に抑えることができ、より高精度に特定ガスの濃度を測定することができる。 The first reflecting surface 30 and the second reflecting surface 31 are formed so as to be relatively detachable, and as shown in FIG. 1, the packaging bag B is sandwiched between the first reflecting surface 30 and the second reflecting surface 31. It is formed as possible. Therefore, when the packaging bag B is sandwiched between the first reflecting surface 30 and the second reflecting surface 31, the first reflecting surface 30 and the second reflecting surface 31 can be brought into close contact with the packaging bag B.
Further, by determining the positions of the first window portion 16 and the second window portion 23 with respect to the packaging bag B, when the packaging bag B is sandwiched between the first reflecting surface 30 and the second reflecting surface 31, the first window portion B becomes the first. The window portion 16 and the second window portion 23 can also be brought into close contact with each other.
As a result, when the laser beam is emitted from the first window portion 16 to be reflected by the second reflecting surface 31 and the first reflecting surface 30 and incident on the second window portion 23, the specific gas contained in the atmosphere The influence of the above can be minimized, and the concentration of a specific gas can be measured with higher accuracy.

第１窓部１６と第２窓部２３の位置は、レーザー光を第１窓部１６から射出して第２窓部２３へ入射させる間に第１反射面３０と第２反射面３１で反射可能となるように配置すれば良く、第１窓部１６と第２窓部２３間の距離と、第１窓部１６から射出されるレーザ光が第２反射面３０へ入射するときの所定の入射角度との関係によって、第１反射面３０と第２反射面３１との間でレーザー光を所定の偶数回反射させて、第２窓部２３へ入射させるように制御することができる。 The positions of the first window portion 16 and the second window portion 23 are reflected by the first reflecting surface 30 and the second reflecting surface 31 while the laser light is emitted from the first window portion 16 and incident on the second window portion 23. It may be arranged so as to be possible, and the distance between the first window portion 16 and the second window portion 23 and a predetermined value when the laser light emitted from the first window portion 16 enters the second reflecting surface 30. Depending on the relationship with the incident angle, it is possible to control the laser light to be reflected a predetermined even number of times between the first reflecting surface 30 and the second reflecting surface 31 so as to be incident on the second window portion 23.

レーザ光を第１窓部１６から射出され第２反射面２４へ入射させるとき、当該レーザー光の入射角度θは、たとえば、図４に示すように、５度から８５度の間で任意に設定することができ、さらに第１反射面３０と第２反射面３１間の距離に基づいて光路長の計算を容易に行うことができる、３０度又は６０度、或いは４５度が好ましい。入射角度が５度以下の場合、第１窓部１６と第２窓部２３が正対している従来の場合と光路長の差が大きくならないうえ、レーザー光が、複数回反射している包装袋Ｂ内の一点でガス濃度を測定することとなるので、包装袋Ｂ内部にガスの偏りがあった場合、誤差が生じやすくなるおそれがある。一方、入射角度が８５度以上の場合、包装袋Ｂを透過するレーザー光が特定ガスに吸収されるよりも散乱される割合が大きくなり、ガス濃度の測定で誤差が生じやすくなるおそれがある。 When the laser light is emitted from the first window portion 16 and incident on the second reflecting surface 24, the incident angle θ of the laser light is arbitrarily set between 5 degrees and 85 degrees, for example, as shown in FIG. 30 degrees, 60 degrees, or 45 degrees is preferable, because the optical path length can be easily calculated based on the distance between the first reflecting surface 30 and the second reflecting surface 31. When the incident angle is 5 degrees or less, the difference in optical path length does not increase from the conventional case where the first window portion 16 and the second window portion 23 face each other, and the laser beam is reflected multiple times in the packaging bag. Since the gas concentration is measured at one point in B, if there is a bias in the gas inside the packaging bag B, an error may easily occur. On the other hand, when the incident angle is 85 degrees or more, the ratio of the laser light transmitted through the packaging bag B being absorbed by the specific gas is larger than that of being absorbed by the specific gas, and there is a possibility that an error may easily occur in the measurement of the gas concentration.

また、第１反射面３０と第２反射面３１との間を反射させる反射回数は、第１窓部１６と第２窓部２３を対向配置していることから、偶数回反射するように構成されている。ここで、反射回数は特定ガスに対するレーザー光の吸収と散乱の関係から２回若しくは４回が好ましい。６回以上反射させると、光路長を長くすることができるが、レーザー光の減衰率が大きくなるため、レーザー受光部に高感度な受光センサを設けなければならない。そのため、コストが増大するおそれがある。 Further, the number of times of reflection reflected between the first reflecting surface 30 and the second reflecting surface 31 is configured to be reflected an even number of times because the first window portion 16 and the second window portion 23 are arranged to face each other. Has been done. Here, the number of reflections is preferably 2 or 4 from the relationship between absorption and scattering of laser light for a specific gas. When the light is reflected 6 times or more, the optical path length can be lengthened, but the attenuation rate of the laser light becomes large, so that a highly sensitive light receiving sensor must be provided in the laser light receiving portion. Therefore, the cost may increase.

ここで、波長可変半導体レーザー吸収分光法（ＴＤＬＡＳ）は、ランバート・ベールの法則に基づいてガス濃度を測定するものである。ランバート・ベールの法則とは、図３に示すように、入射光強度をＩ０、包装袋Ｂを透過した透過光強度をＩｔ、入射光に対する透過光の透過率をＴとして、光路長をＬ、ガス濃度をＣとすると、特定波長の吸収スペクトルで射出されたレーザー光の吸光度Ａとの間に、数式１が成立する関係である。ここでεは測定対象となる所定のガスがレーザー光を吸収する固有の吸収係数である。 Here, the tunable semiconductor laser absorption spectroscopy (TDLAS) measures the gas concentration based on Lambert-Beer's law. As shown in FIG. 3, Lambert-Beer's law is that the incident light intensity is I 0 , the transmitted light intensity transmitted through the packaging bag B is It, the transmittance of the transmitted light with respect to the incident light is T, and the optical path length is L. Assuming that the gas concentration is C, the relationship is such that Equation 1 holds with the absorbance A of the laser light emitted in the absorption spectrum of a specific wavelength. Here, ε is a unique absorption coefficient at which a predetermined gas to be measured absorbs laser light.

Figure 2021067631
Figure 2021067631

第１反射面３０と第２反射面３１との間の距離とレーザー光を反射させる反射回数から光路長Ｌを容易に求めることができることから、入射光に対する透過光の透過率Ｔ、または包装袋内で特定ガスに吸収されたレーザー光の特定波長に係る吸収スペクトルの吸光度Ａを得ることが出来れば、ガス濃度Ｃを求めることができる。
ここで、特定ガスは包装袋Ｂに密封されているから、ガス濃度Ｃを定量測定する場合、入射光に対する透過光の透過率Ｔ又は吸収スペクトルの吸光度Ａが大きく変化するように、すなわち、吸光度Ａに比例する光路長Ｌを長くするとガス濃度の検知感度を向上させることができる。このように検知感度を向上させることによって、たとえば数ｐｐｍレベルのガス濃度まで検知できるように検知可能範囲を広げた場合、数％レベルのガス濃度の測定は容易に行うことができ、その測定精度を大きく向上させることができる。
したがって、以下に例示するように、第１反射面３０上に設ける第１窓部１６と、第２反射面３１上に設ける第２窓部２３の位置を定めて、第１反射面３０と第２反射面３１との間でレーザー光を複数回反射させることによって、光路長を長くすることによって、測定精度を向上させることができる。 Since the optical path length L can be easily obtained from the distance between the first reflecting surface 30 and the second reflecting surface 31 and the number of reflections that reflect the laser light, the transmittance T of the transmitted light with respect to the incident light or the packaging bag. If the absorbance A of the absorption spectrum related to the specific wavelength of the laser light absorbed by the specific gas can be obtained, the gas concentration C can be obtained.
Here, since the specific gas is sealed in the packaging bag B, when the gas concentration C is quantitatively measured, the transmittance T of the transmitted light with respect to the incident light or the absorbance A of the absorption spectrum changes significantly, that is, the absorbance. By increasing the optical path length L proportional to A, the detection sensitivity of the gas concentration can be improved. By improving the detection sensitivity in this way, for example, when the detectable range is expanded so that gas concentration of several ppm level can be detected, measurement of gas concentration of several% level can be easily performed, and the measurement accuracy thereof. Can be greatly improved.
Therefore, as illustrated below, the positions of the first window portion 16 provided on the first reflecting surface 30 and the second window portion 23 provided on the second reflecting surface 31 are determined, and the first reflecting surface 30 and the second window portion 23 are determined. By reflecting the laser beam a plurality of times with the two reflecting surfaces 31, the optical path length can be lengthened, and the measurement accuracy can be improved.

第１窓部１６の位置と第２窓部２３の位置は、たとえば、図４に示した第１反射パターンから図６に示した第３反射パターンのように配置し、それに伴うレーザー光の光跡もまた次のように例示することができる。
なお、本実施例に係るガス濃度測定装置の第１窓部１６と第２窓部２３の配置と反射回数は以下の例示に限定されるものではなく、本実施例に係るガス濃度測定装置が測定する包装袋の大きさ、厚み、レーザー光の透過しやすさ等に応じて最適な透過率、吸光度を得るために任意に設定することができる。 The position of the first window portion 16 and the position of the second window portion 23 are arranged, for example, from the first reflection pattern shown in FIG. 4 to the third reflection pattern shown in FIG. Traces can also be illustrated as follows.
The arrangement and the number of reflections of the first window portion 16 and the second window portion 23 of the gas concentration measuring device according to this embodiment are not limited to the following examples, and the gas concentration measuring device according to this embodiment is used. It can be arbitrarily set in order to obtain the optimum transmittance and absorbance according to the size and thickness of the packaging bag to be measured, the ease of transmitting laser light, and the like.

図４は、ガス濃度測定装置１０の第１反射面３０と第２反射面３１の横断面図である。第１反射パターンは、図４に示すように、第１反射面３０と第２反射面３１とを平面視したとき、第１窓部１６と第２窓部２３が同一平面上で、第１窓部１６に対して第２窓部２３が対角に配置されているパターンである。
第１反射パターンは、第１窓部１６から射出されるレーザー光を第２反射面３１に対して３０度の入射角で反射させている。その後、平行に相対する第１反射面３０と第２反射面３１との間で、図４に示すように４回反射して第２窓部２３へ入射するように形成されている。ここで、図７に示した従来の主ヘッド３と副ヘッド５が正対している場合の光路長を１０ｍｍ、すなわち第１反射面と第２反射面との間の距離を１０ｍｍとすると、図４に示した光路長は従来例に対しておよそ６倍となる約５７．８ｍｍまで伸ばすことができる。 FIG. 4 is a cross-sectional view of the first reflecting surface 30 and the second reflecting surface 31 of the gas concentration measuring device 10. In the first reflection pattern, as shown in FIG. 4, when the first reflection surface 30 and the second reflection surface 31 are viewed in a plane, the first window portion 16 and the second window portion 23 are on the same plane, and the first reflection pattern is obtained. This is a pattern in which the second window portion 23 is arranged diagonally with respect to the window portion 16.
The first reflection pattern reflects the laser light emitted from the first window portion 16 with respect to the second reflection surface 31 at an incident angle of 30 degrees. After that, it is formed so as to be reflected four times and incident on the second window portion 23 between the first reflecting surface 30 and the second reflecting surface 31 which are opposed to each other in parallel as shown in FIG. Here, assuming that the optical path length when the conventional main head 3 and the sub head 5 shown in FIG. 7 face each other is 10 mm, that is, the distance between the first reflecting surface and the second reflecting surface is 10 mm, FIG. The optical path length shown in 4 can be extended to about 57.8 mm, which is about 6 times that of the conventional example.

図５は、ガス濃度測定装置１０の第１反射面３０と第２反射面３１の縦断面図である。第２反射パターンは、図５に示すように、第１反射面３０と第２反射面３１の縦断面を側面視したとき、第１窓部１６に対して第２窓部２３が下方へ対角に配置されているパターンである。
第２反射パターンは、第１窓部１６から射出されるレーザー光を第２反射面３１に対して４５度の入射角で反射させている。その後、平行に相対する第１反射面３０と第２反射面３１との間で、図５に示すように４回反射して第２窓部２３へ入射するように形成されている。ここで、図５に示した従来の主ヘッド３と副ヘッド５が正対している場合の光路長を１０ｍｍ、すなわち第１反射面３０と第２反射面との間の距離を１０ｍｍとすると、図５に示した光路長は従来例に対しておよそ７倍となる７０．７ｍｍまで伸ばすことができる。 FIG. 5 is a vertical cross-sectional view of the first reflecting surface 30 and the second reflecting surface 31 of the gas concentration measuring device 10. In the second reflection pattern, as shown in FIG. 5, when the vertical cross section of the first reflection surface 30 and the second reflection surface 31 is viewed from the side, the second window portion 23 faces downward with respect to the first window portion 16. It is a pattern arranged at the corner.
The second reflection pattern reflects the laser light emitted from the first window portion 16 with respect to the second reflection surface 31 at an incident angle of 45 degrees. After that, it is formed so as to be reflected four times and incident on the second window portion 23 between the first reflecting surface 30 and the second reflecting surface 31 which are opposed to each other in parallel as shown in FIG. Here, assuming that the optical path length when the conventional main head 3 and the sub head 5 shown in FIG. 5 face each other is 10 mm, that is, the distance between the first reflecting surface 30 and the second reflecting surface is 10 mm. The optical path length shown in FIG. 5 can be extended to 70.7 mm, which is about 7 times that of the conventional example.

図６は、ガス濃度測定装置１０の第１反射面３０と第２反射面を俯瞰した斜視図である。図６に示す第３反射パターンは、頂点に第１窓部１６と第２窓部２３を含む直方体を想定したとき、第１窓部１６に対して第２窓部２３が包装袋Ｂを挟んで下方へ対角に配置されているパターンである。
ここで、図６に示すように、レーザー光を４回反射させた場合、たとえば、第３反射パターンについて想定した上記の直方体について、高さと幅が５０ｍｍで、第１反射面と第２反射面との距離、すなわち奥行きが１０ｍｍの直方体としたとき、たとえば、第１窓部と第２窓部の間には、１辺が１０ｍｍの立方体が階段状に５つ連接して配置されていることとなる。このとき、当該立方体の対角線に沿ってレーザー光を射出した場合、当該対角線の長さは１０√３となるから、第１窓部から第１反射面と第２反射面との間で４回反射して第２窓部へ入射されるレーザー光の光路長は、図７に示した従来の主ヘッド３と副ヘッド５が正対している場合の光路長を１０ｍｍ、すなわち、第１反射面３０と第２反射面３１との間の距離を１０ｍｍとすると、図６に示した光路長は従来例に対して５×１０√３となるから、およそ８．６倍の約８６．６ｍｍとなる。 FIG. 6 is a perspective view of the first reflecting surface 30 and the second reflecting surface of the gas concentration measuring device 10 from a bird's-eye view. In the third reflection pattern shown in FIG. 6, assuming a rectangular parallelepiped including the first window portion 16 and the second window portion 23 at the apex, the second window portion 23 sandwiches the packaging bag B with respect to the first window portion 16. It is a pattern that is arranged diagonally downward.
Here, as shown in FIG. 6, when the laser beam is reflected four times, for example, the above-mentioned rectangular parallelepiped assuming the third reflection pattern has a height and a width of 50 mm, and a first reflection surface and a second reflection surface. When a rectangular parallelepiped with a distance of 10 mm, that is, a depth of 10 mm is used, for example, five cubes having a side of 10 mm are arranged in a stepped manner between the first window portion and the second window portion. It becomes. At this time, when the laser light is emitted along the diagonal line of the cube, the length of the diagonal line is 10√3, so that the first window portion between the first reflecting surface and the second reflecting surface four times. The optical path length of the laser beam that is reflected and incident on the second window portion is 10 mm, that is, the optical path length when the conventional main head 3 and the sub head 5 shown in FIG. 7 face each other, that is, the first reflecting surface. Assuming that the distance between 30 and the second reflecting surface 31 is 10 mm, the optical path length shown in FIG. 6 is 5 × 10√3 as compared with the conventional example, so that it is about 86.6 mm, which is about 8.6 times. Become.

本実施例に係るガス濃度測定方法に係るガス濃度測定装置は上記の構成を有する。次に本実施例に係るガス濃度測定方法を添付した図面にしたがって説明する。 The gas concentration measuring device according to the gas concentration measuring method according to this embodiment has the above configuration. Next, the gas concentration measuring method according to this embodiment will be described with reference to the attached drawings.

ガス濃度測定方法は、図１及び図２に示すように、まずガス濃度測定装置１０の第１反射面３０と第２反射面３１の間に、測定対象の包装袋Ｂが配置される。そして、図４から図６に例示したように、ガス濃度測定装置１０の第１反射面３０と第２反射面３１が包装袋Ｂを挟持する。これによって、第１窓部１６と第１反射面３０、及び第２窓部２３と第２反射面３１を包装袋Ｂへ密着させることができる。さらに、この反射面３０，３１が包装袋Ｂを挟持するとき、たとえば、包装機に設けた検査工程であれば、図１に示すように、包装袋Ｂの袋口近傍を左右からクリップ６，６で引張しているので、包装袋Ｂ表面のしわを伸ばして、第１反射面３０と第２反射面３１へより一層密着させることができる。
これによって、第１反射面３０と第２反射面３１との距離を一定にすることができるので、レーザー光の光路長を一定にすることができる。また、包装袋Ｂを挟持するとき、当該包装袋Ｂを第１反射面３０と第２反射面３１が押圧するため、包装袋Ｂに密封した窒素等の不活性ガスが漏れているか否かを検査することができる。さらには、包装袋Ｂを密着させるため、第１窓部１６、第２窓部２３や第１反射面３０、第２反射面３１と包装袋Ｂの境界における大気の影響を除去することができ、測定精度を上げることができる。 In the gas concentration measuring method, as shown in FIGS. 1 and 2, first, the packaging bag B to be measured is arranged between the first reflecting surface 30 and the second reflecting surface 31 of the gas concentration measuring device 10. Then, as illustrated in FIGS. 4 to 6, the first reflecting surface 30 and the second reflecting surface 31 of the gas concentration measuring device 10 sandwich the packaging bag B. As a result, the first window portion 16 and the first reflecting surface 30, and the second window portion 23 and the second reflecting surface 31 can be brought into close contact with the packaging bag B. Further, when the reflective surfaces 30 and 31 sandwich the packaging bag B, for example, in the inspection process provided in the packaging machine, as shown in FIG. 1, the vicinity of the bag mouth of the packaging bag B is clipped from the left and right 6, Since it is pulled by No. 6, the wrinkles on the surface of the packaging bag B can be smoothed so that the first reflective surface 30 and the second reflective surface 31 can be further brought into close contact with each other.
As a result, the distance between the first reflecting surface 30 and the second reflecting surface 31 can be made constant, so that the optical path length of the laser beam can be made constant. Further, when the packaging bag B is sandwiched, the first reflecting surface 30 and the second reflecting surface 31 press the packaging bag B, so whether or not an inert gas such as nitrogen sealed in the packaging bag B is leaking. Can be inspected. Further, since the packaging bag B is brought into close contact with each other, the influence of the atmosphere at the boundary between the first window portion 16, the second window portion 23, the first reflecting surface 30, the second reflecting surface 31, and the packaging bag B can be removed. , The measurement accuracy can be improved.

包装袋Ｂが第１反射面３０と第２反射面３１に挟持された後、続いてレーザー発生部１１から第１窓部１６を通じてレーザー光が射出される。レーザー光は第２反射面３１に対して、たとえば、図４から図６に示したように、所定の入射角度で入射され、第２反射面３１で反射する。その後、レーザー光は、第１反射面３０、続いて第２反射面３１、さらに第１反射面３０と順に反射してから、第２窓部２３を通じてレーザー受光部１２で受光される。 After the packaging bag B is sandwiched between the first reflecting surface 30 and the second reflecting surface 31, laser light is subsequently emitted from the laser generating portion 11 through the first window portion 16. The laser light is incident on the second reflecting surface 31 at a predetermined incident angle, for example, as shown in FIGS. 4 to 6, and is reflected by the second reflecting surface 31. After that, the laser light is reflected in the order of the first reflecting surface 30, the second reflecting surface 31, and the first reflecting surface 30, and then is received by the laser receiving unit 12 through the second window unit 23.

そして、レーザー受光部１２の受光センサ２０は、包装袋Ｂを透過したレーザー光を電子的な透過光信号へ変換する。当該透過光信号は、測定部２１へ出力される。
測定部２１は、上記の透過光信号と、レーザー発生部１１が射出したレーザー光を電子的に変換した入射光信号を取得し、透過光信号と入射光信号を比較して、レーザー光の包装袋に対する透過率Ｔを測定する。そして、当該透過率Ｔに基づいて、包装袋Ｂ内の特定ガスに吸収されたレーザー光の特定波長の吸収スペクトルの吸光度Ａが計算され、当該吸光度Ａに基づいて包装袋内の特定ガスのガス濃度Ｃが測定される。
これによって、ガス濃度測定装置１０は、包装袋Ｂ内部の特定ガスのガス濃度Ｃを測定することができる。 Then, the light receiving sensor 20 of the laser light receiving unit 12 converts the laser light transmitted through the packaging bag B into an electronic transmitted light signal. The transmitted light signal is output to the measuring unit 21.
The measuring unit 21 acquires the above-mentioned transmitted light signal and the incident light signal obtained by electronically converting the laser light emitted by the laser generating unit 11, compares the transmitted light signal with the incident light signal, and packages the laser light. The transmittance T for the bag is measured. Then, based on the transmittance T, the absorbance A of the absorption spectrum of the laser beam absorbed by the specific gas in the packaging bag B at a specific wavelength is calculated, and the gas of the specific gas in the packaging bag is calculated based on the absorbance A. Concentration C is measured.
As a result, the gas concentration measuring device 10 can measure the gas concentration C of the specific gas inside the packaging bag B.

なお、本実施例において、反射面を第１反射面３０と第２反射面３１の二面からなるように構成したがこれに限定されるものではない。たとえば、一枚の反射面に対してレーザー光を反射させることによってもまた光路長を延ばすことができる。この場合には、レーザー発生部１１とレーザー受光部１２を、同一の側に並べて設置することができるので、たとえば、ロータリー式包装機のように包装に係る各種工程を担う装置をスペースが限られた包装機上にレイアウトする場合に効果がある。さらに、本実施例と同様に第１反射面３０と第２反射面３１を設けた場合であっても、たとえば、第１反射面３０に第１窓部１６と第２窓部２３を設けた場合、レーザー発生部１１から第１窓部１６を通じて射出したレーザー光は、奇数回の反射で第２窓部２３を通じてレーザー受光部１２へ入射させることができる。この場合であっても本実施例と同様に光路長を長くすることができるので測定精度を向上させることができる。 In this embodiment, the reflective surface is configured to be composed of two surfaces, a first reflective surface 30 and a second reflective surface 31, but the present invention is not limited to this. For example, the optical path length can also be extended by reflecting the laser beam on one reflecting surface. In this case, since the laser generating unit 11 and the laser receiving unit 12 can be installed side by side on the same side, space is limited for a device that handles various processes related to packaging, such as a rotary packaging machine. It is effective when laying out on a laser packaging machine. Further, even when the first reflecting surface 30 and the second reflecting surface 31 are provided as in the present embodiment, for example, the first window portion 16 and the second window portion 23 are provided on the first reflecting surface 30. In this case, the laser light emitted from the laser generating unit 11 through the first window unit 16 can be incident on the laser receiving unit 12 through the second window unit 23 with an odd number of reflections. Even in this case, the optical path length can be lengthened as in the present embodiment, so that the measurement accuracy can be improved.

また、本実施例において、レーザー光が射出される第１窓部１６と、レーザー光が入射する第２窓部２３を例示したが、これに限定されるものではない。
たとえば、レーザー発生部１１から射出されるレーザー光を光ファイバーで分光して、第１反射面３０に設けた二つ以上の窓部から射出し、射出された複数本のレーザー光が互いに触れて干渉しないように第１反射面３０と第２反射面３１との間で複数回反射させてから、第２反射面３１に設けた二つ以上の窓部に入射させる多点測定を行っても良い。この場合には、包装袋Ｂ内の複数か所を同時に測定することができるので、平均を取って補正等を行うことによって、測定精度を向上させることができる。 Further, in this embodiment, the first window portion 16 from which the laser light is emitted and the second window portion 23 into which the laser light is incident have been illustrated, but the present invention is not limited thereto.
For example, the laser light emitted from the laser generator 11 is separated by an optical fiber and emitted from two or more windows provided on the first reflecting surface 30, and the plurality of emitted laser beams touch each other and interfere with each other. It is also possible to perform multipoint measurement in which the first reflecting surface 30 and the second reflecting surface 31 are reflected a plurality of times so as not to be reflected, and then the light is incident on two or more windows provided on the second reflecting surface 31. .. In this case, since a plurality of locations in the packaging bag B can be measured at the same time, the measurement accuracy can be improved by taking an average and performing correction or the like.

本実施例に係るガス濃度測定方法によれば、第１反射面３０と第２反射面３１で包装袋を挟持して、第１窓部１６と第１反射面３０、並びに第２窓部２３と第２反射面３１が包装袋Ｂに密着するようにした。
これによって、包装袋Ｂの厚みがバラバラであっても、当該包装袋Ｂを挟持する第１反射面３０と第２反射面３１との距離を一定にしたり、また当該距離を測定することで容易に光路長Ｌを決定することができる。光路長Ｌがわかれば、入射光に対する透過光の透過率Ｔを測定することによって、測定対象の特定ガスに固有の吸収波長帯に含まれた複数の吸収線のうち、一の吸収線に係る特定波長に合致するよう変調したレーザー光の吸収スペクトルの吸光度Ａを求めることができ、当該吸光度Ａに基づいて、包装袋内の特定ガスのガス濃度Ｃを容易に求めることができる。
また、第１窓部１６を設けた第１反射面３０、第２窓部２３を設けた第２反射面３１が包装袋Ｂに密着するように構成したことによって、第１窓部１６、及び第２窓部２４と、包装袋Ｂとの間の大気を押し出して測定することができるので、大気中に含まれている特定ガスによる誤差を極めて小さくすることができ、測定精度を向上させることができる。 According to the gas concentration measuring method according to the present embodiment, the packaging bag is sandwiched between the first reflecting surface 30 and the second reflecting surface 31, and the first window portion 16, the first reflecting surface 30, and the second window portion 23 are sandwiched. The second reflective surface 31 is brought into close contact with the packaging bag B.
As a result, even if the thickness of the packaging bag B is different, it is easy to keep the distance between the first reflecting surface 30 and the second reflecting surface 31 that sandwich the packaging bag B constant, or to measure the distance. The optical path length L can be determined. If the optical path length L is known, the transmittance T of the transmitted light with respect to the incident light is measured to relate to one of the plurality of absorption lines included in the absorption wavelength band peculiar to the specific gas to be measured. The absorbance A of the absorption spectrum of the laser light modulated to match a specific wavelength can be obtained, and the gas concentration C of the specific gas in the packaging bag can be easily determined based on the absorbance A.
Further, the first window portion 16 and the first window portion 16 and the first window portion 16 are configured so that the first reflective surface 30 provided with the first window portion 16 and the second reflective surface 31 provided with the second window portion 23 are in close contact with the packaging bag B. Since the air between the second window portion 24 and the packaging bag B can be extruded for measurement, the error due to the specific gas contained in the air can be extremely reduced, and the measurement accuracy can be improved. Can be done.

１０…ガス濃度測定装置、１１…レーザー発生部、１２…レーザー受光部、
１３…レーザー光源、１４…制御部、１５…第１ハウジング、１６…第１窓部、
２０…受光センサ、２１…測定部、２２…第２ハウジング、２３…第２窓部、
３０…第１反射面、３１…第２反射面、
１…従来のガス濃度測定装置、２…従来のレーザー発生部、３…主ヘッド、４…従来のレーザー受光部、５…副ヘッド、６…グリップ、
Ｂ…包装袋。 10 ... Gas concentration measuring device, 11 ... Laser generating unit, 12 ... Laser receiving unit,
13 ... laser light source, 14 ... control unit, 15 ... first housing, 16 ... first window unit,
20 ... light receiving sensor, 21 ... measurement unit, 22 ... second housing, 23 ... second window unit,
30 ... 1st reflective surface, 31 ... 2nd reflective surface,
1 ... Conventional gas concentration measuring device, 2 ... Conventional laser generator, 3 ... Main head, 4 ... Conventional laser receiver, 5 ... Sub head, 6 ... Grip,
B ... Packaging bag.

Claims (2)

特定波長のレーザー光を、ガス置換されて密封された包装袋に透過させて、前記包装袋の透過前後で変化する特定波長の吸収スペクトルに基づいて前記包装袋の内部に残留している特定ガスのガス濃度を測定するようにしたレーザー式ガス濃度計を有するガス濃度測定方法であって、
前記レーザー光を射出するレーザー発生部と、
前記レーザー光を受光するレーザー受光部と、
前記レーザー光が反射可能な反射面を有し、
前記レーザー発生部から射出され、前記包装袋を透過するレーザー光が、前記反射面で反射した後に前記レーザー受光部に入射するようにしたことを特徴とするガス濃度測定方法。 A laser beam of a specific wavelength is transmitted through a sealed packaging bag that has been gas-replaced, and the specific gas remaining inside the packaging bag is based on an absorption spectrum of the specific wavelength that changes before and after transmission of the packaging bag. It is a gas concentration measuring method having a laser type gas densitometer for measuring the gas concentration of the above.
The laser generating part that emits the laser light and
A laser receiving unit that receives the laser light and
It has a reflective surface on which the laser beam can be reflected, and has a reflective surface.
A method for measuring a gas concentration, characterized in that a laser beam emitted from the laser generating portion and transmitted through the packaging bag is reflected by the reflecting surface and then incident on the laser receiving portion. 前記反射面が、前記包装袋を挟んで互いに平行に対向した第１反射面と第２反射面からなり、
前記レーザー光が、前記第１反射面と前記第２反射面との間で複数回反射するようにしたことを特徴とする請求項１に記載のガス濃度測定方法。 The reflective surface comprises a first reflective surface and a second reflective surface that face each other in parallel with the packaging bag in between.
The gas concentration measuring method according to claim 1, wherein the laser beam is reflected a plurality of times between the first reflecting surface and the second reflecting surface.
JP2019195094A 2019-10-28 2019-10-28 Method of measuring gas concentration in packaging bag Pending JP2021067631A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2019195094A JP2021067631A (en) 2019-10-28 2019-10-28 Method of measuring gas concentration in packaging bag

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2019195094A JP2021067631A (en) 2019-10-28 2019-10-28 Method of measuring gas concentration in packaging bag

Publications (1)

Publication Number Publication Date
JP2021067631A true JP2021067631A (en) 2021-04-30

Family

ID=75637105

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2019195094A Pending JP2021067631A (en) 2019-10-28 2019-10-28 Method of measuring gas concentration in packaging bag

Country Status (1)

Country Link
JP (1) JP2021067631A (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009014589A (en) * 2007-07-06 2009-01-22 General Packer Co Ltd Gas concentration measuring method in packaging machine
JP2010521676A (en) * 2007-03-13 2010-06-24 アドヴァンスト リキッド ロジック インコーポレイテッド Droplet actuator apparatus, configuration and method for improved absorbance detection
JP2011220689A (en) * 2010-04-02 2011-11-04 Shimadzu Corp Gas analyzing apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010521676A (en) * 2007-03-13 2010-06-24 アドヴァンスト リキッド ロジック インコーポレイテッド Droplet actuator apparatus, configuration and method for improved absorbance detection
JP2009014589A (en) * 2007-07-06 2009-01-22 General Packer Co Ltd Gas concentration measuring method in packaging machine
JP2011220689A (en) * 2010-04-02 2011-11-04 Shimadzu Corp Gas analyzing apparatus

Similar Documents

Publication Publication Date Title
JP2021067634A (en) Device for measuring gas concentration in packaging bag
US7948626B2 (en) Method for the automated measurement of gas pressure and concentration inside sealed containers
JP7210442B2 (en) Method and apparatus for measuring gas concentration
WO2021085331A1 (en) Laser gas concentration meter
US6639678B1 (en) Apparatus and method for nondestructive monitoring of gases in sealed containers
CN104903704B (en) Carry out the tunable diode laser absorption spectroscopy of steam measure
US11378483B2 (en) System and method for determining the integrity of containers by optical measurement
JP7357918B2 (en) Gas concentration measuring device inside packaging bag
US8994948B2 (en) Apparatus for the non-destructive testing of the integrity and/or suitability of sealed packagings
JP2018510346A (en) System and method for determining container integrity by optical measurement
JP4948145B2 (en) Gas detector
JP2021067631A (en) Method of measuring gas concentration in packaging bag
JP5337953B2 (en) Gas concentration measuring method and gas concentration measuring device
US10088416B2 (en) Method and device for determining gas component inside a transparent container
JP2021067633A (en) Method of measuring gas concentration in packaging bag
JP7343169B2 (en) Gas concentration measurement method and gas concentration measurement device for sealed packaging containers
JP7355381B2 (en) sealed packaging containers
Cocola et al. Design and evaluation of an in-line system for gas sensing in flow-packed products
KR20150085488A (en) Method and device for determing gas component inside a transparent container
WO2021124711A1 (en) Method for measuring gas concentration in packaging container
JP7339663B2 (en) Gas concentration measuring method for sealed packaging container and gas concentration measuring device used therefor
JP7339662B2 (en) Gas concentration measuring method for sealed packaging container and gas concentration measuring device used therefor
JP2021096133A (en) Gas concentration measuring device for packaging bags
US20230221249A1 (en) System and method for determining at least one property of a porous medium
WO2023057471A1 (en) System and method for measuring a property of a gas in a container

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20220906

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20230426

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20230502

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20230630

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20230718

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20240123