System and method for measuring properties of a gas in a vessel - Patents.com

Abstract

A method and system are provided for performing an in-line measurement to determine at least one characteristic of a gas in a closed container by using the intensity profile to determine a position of the closed container relative to a light sensor.

Description

[Technical field]

[0001] The present disclosure relates to determining a property of a gas in a closed container by performing an optical measurement. The property may relate to the pressure and / or the gas composition in the container. In particular, the present disclosure relates to a triggering method for establishing that the closed container is in the beam path of an optical sensor used to measure the property of the gas. [Background technology]

[0002] When performing optical measurements on gases in closed vessels, it is important to use the correct data for property estimation in order to achieve high sensitivity and accuracy.

[0003] For in-line measurements on transport bands and the like, obtaining correct data requires a starting point for when to begin recording and when to stop recording data that is used to determine the properties of the gas.

[0004] A separate triggering device is typically used to detect the location of the container to be measured in order to determine when to start and stop recording, and upon detecting the container at the location where the measurement is to be performed, triggers a measurement device used to perform the optical measurement on the container.

[0005] A method for obtaining the start and end points of the intensity profile for a measurement on a container is described in WO2016 / 051341. In that disclosure, a separate triggering device is used and a positioning sensor is used to determine the position of the container and trigger the laser measurement. In that disclosure, a period for recording the spectrum is first determined based on the position sensor (separate triggering device) and the speed of the container. An intensity profile is then recorded over that period during which the bottle passes through the laser beam used to obtain the intensity profile. After the intensity profile is recorded, minima in the intensity profile due to low transmission through the container walls to and from the detection area are determined and sub-windows of the intensity profile between the minima are determined and used to calculate the gas pressure in the container.

[0006] This method has some drawbacks, for example the entire intensity profile needs to be recorded before the minimum can be found, and furthermore, the method relies on an additional sensor to detect the position of the container.

[0007] Therefore, improved systems and methods for triggering optical measurements of gases in a vessel would be advantageous, preferably if the system could be smaller, faster, and adaptable to vessels of various sizes, all of which are advantages of in-line measurements. Summary of the Invention

[0008] Accordingly, embodiments of the present disclosure seek to mitigate, alleviate or eliminate one or more deficiencies, disadvantages or problems in the art, such as those identified above, singly or in combination, by providing a system or method according to the appended claims for non-destructively determining the characteristics of a gas in a closed container.

[0009] A first aspect of the present disclosure relates to a method of performing an in-line measurement to determine at least one characteristic of at least one gas in a closed vessel, the closed vessel including a measurement region having a predetermined diameter. The method may include emitting a light beam between a light source and a detector, the light beam may be transmitted through the detection region. The light beam may have a wavelength tunable to an absorption wavelength of the gas.

[0010] The method may also include obtaining a transmission signal from a detector associated with the light beam transmitted through the detection region.

[0011] Additionally, the method may also include advancing the closed container toward the detection region at a predetermined speed.

[0012] The method may also include determining when the closed container enters the detection region based on an analysis of the transmitted signal.

[0013] The method may also include estimating at least one characteristic of the at least one gas based on a transmission signal associated with a light beam transmitted through a measurement region of the closed container while the closed container advances through the detection region.

[0014] In some examples, the method may include continuously obtaining the transmission signal.

[0015] In some examples, the method may include using the light beam to both determine when a closed container enters a detection region and to estimate at least one characteristic of a gas within the closed container.

[0016] This means that the same sensor is used to both determine when a closed container enters the detection region and to estimate at least one characteristic of the gas within the closed container.

[0017] In some examples, the method may include, wherein the at least one characteristic of the gas includes at least one of a gas pressure within the closed container and / or a concentration of the gas within the closed container.

[0018] In some examples, the method may include the transmission signal being used to determine a rise (increase) and / or fall (decrease) in intensity of the transmission signal due to the closed container entering and / or leaving the detection region.

[0019] In some examples, the method may include a derivative of the strength being used to determine increases and / or decreases in strength of the transmitted signal.

[0020] In some examples, the method may include the light beam being pulsed, with each pulse having a predetermined amplitude, where the pulse amplitude is used to determine rises and / or falls in intensity of the transmitted signal.

[0021] In some examples, the method may include the detector being a PSD, where the transmitted signal is used to determine a deflection of a light beam to detect when a closed container enters and / or exits a detection region.

[0022] In some examples, the method may include using the deflection to determine a rise (increase) and / or fall (decrease) in the strength of the transmitted signal due to a closed container entering and / or exiting the detection region.

[0023] In some examples, the method may include the velocity being used in conjunction with the transmitted signal to determine a start and / or end point of a time period for obtaining data used to estimate at least one characteristic of the gas in the closed vessel.

[0024] In some examples, the method may include setting a start point and / or an end point of the period to a predetermined period based on the velocity after it is determined that the closed container has entered the detection area based on the transmitted signal.

[0025] In some examples, the method may include using a diameter of a measurement area of ​​the closed container to determine an end point of a time period used to obtain data used to estimate a characteristic of a gas within the closed container.

[0026] In some examples, the method may include using the measured time between two of the descents and / or ascents determined based on the strength of the transmitted signal to estimate the speed and / or diameter of the measurement area of ​​the closed vessel.

[0027] In some examples, the method can include the measurement area of ​​the closed container being a portion of the headspace.

[0028] In some examples, the method can include the transmitted signal being used to determine a background concentration of gas within the detection volume when the closed container is not within the detection volume.

[0029] In some examples, the method may include a background concentration of the gas being used to reduce an offset when performing an estimation of the properties of the gas within the closed vessel.

[0030] Another aspect of the present disclosure relates to a system for performing in-line measurements to determine at least one characteristic of a gas in a closed container, the closed container including a measurement region having a predetermined diameter. The system may include an optical sensor configured to emit a light beam between a light source and a detector of the optical sensor, where the light beam is transmittable through the detection region. The light beam may have a wavelength tunable to an absorption wavelength of the gas in the closed container.

[0031] The sensor may be configured to obtain a transmission signal associated with the light beam.

[0032] The system may also include a means for advancing the closed container toward the detection region at a predetermined speed.

[0033] The system may also include a control unit configured to determine when the closed container enters the detection region based on the transmission signal. The control unit may be further configured to estimate at least one property of the at least one gas based on the transmission signal associated with the light beam transmitted through the measurement region of the closed container while the closed container advances through the detection region.

[0034] The system may also include a control unit configured to determine an integrity of the container based on the transmitted optical signal being detected.

[0035] These and other aspects, features and advantages of possible examples of the present disclosure will become apparent and elucidated from the following description of examples of the disclosure, which refers to the accompanying drawings. [Brief description of the drawings]

[0036] [Figure 1] 1 illustrates a schematic example of a container being measured using the system of the present disclosure. [Diagram 2] 1 illustrates a schematic example of measured intensity while a closed container passes through a light beam. [Diagram 3] 2 illustrates a schematic example of a light pulse; [Figure 4] 1 illustrates a schematic example of a flow chart of a method for measuring according to the present disclosure. [Figure 5A] 1 illustrates a schematic carousel for moving containers. [Figure 5B] 5B illustrates measurements performed on containers placed in the carousel illustrated in FIG. 5A. [Figure 5C]5B illustrates measurements performed on containers placed in the carousel illustrated in FIG. 5A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Specific embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0038] The following disclosure focuses on examples of non-destructive testing of closed containers. The present invention is applicable to determining the characteristics of a gas within a closed container. The closed container is at least partially made of an optically transparent material. The closed container may be a bottle, a bale, a jar, an ampoule, a can, etc. The closed container may also be a package, a bag, a tray, etc. The container may be completely filled with at least one gas. In some examples, the closed container may be at least partially filled with a content, such as a liquid or solid. When the container is partially filled with a content, the container may include a head space filled with a gas.

[0039] Determining the properties of a gas in a closed container can provide useful information, for example, such measurements can be useful for determining the integrity of the container. The integrity of a closed container can provide information about whether the container is properly sealed or whether the container is leaking. The properties can also provide information about the contents within the container.

[0040] The characteristic may relate to obtaining a gas pressure within a closed vessel and / or determining a gas, such as a gas concentration.

[0041] The container can be a sealed bag or a sealed tray containing at least one gas, an example of which can be a gas-exchanged (MAP) container. Gas exchange is commonly used in packaging to improve shelf life, for example in food packaging, pharmaceuticals, etc., the gases commonly used are carbon dioxide (CO2) or nitrogen (N2) to reduce the amount of oxygen (O2). This is made to slow the growth of aerobic organisms and prevent oxidation reactions. It is therefore important to monitor these packages and ensure that there are no leaks, for example during packaging. Besides carbon dioxide (CO2) and oxygen (O2), other gases can also be monitored depending on the container and the product.

[0042] The present disclosure is particularly directed to methods for determining when a closed container is in the beam path and a measurement can be taken.

[0043] The method described herein has the advantage that it can be carried out with a less extensive mechanical set-up.

[0044] Both the pressure and the gas composition inside the vessel can be measured using optical absorption spectroscopy. In particular, tunable diode laser absorption spectroscopy (TDLAS) can be applied.

[0045] 1 illustrates a schematic example of a system 100. The system is designed for optical measurements to estimate properties of a gas 2 in a container 1. The container may include contents 3 and a headspace 2 filled with gas. The container is illustrated as being located in a detection region 4.

[0046] The detection area 4 may be defined by a partial enclosure 5, such as two opposing walls, a tunnel, or a walled space. The walled space may, for example, be arranged in an arch or have an inverted U-shape.

[0047] The detection area 4 may include light sensors 6, 7. The light sensors 6, 7 may be located on opposing walls of the partial enclosure 5. The light sensors are configured to emit a light beam that is transmitted through the detection area 4 between the light source 6 and the detector 7. Alternatively, the light source 6 and the detector 7 are located on the same side and a reflective member is located on the opposite side. The reflective member may diffuse the light.

[0048] The sensors 6, 7 may be configured to measure the headspace 2 of the vessel 1. Preferably, the sensors 6, 7 are designed or adjusted to detect a spectroscopic signal of at least one of the gases present in the vessel 1.

[0049] The light beam transmitted through the detection region 4 may have a wavelength that is tunable to match the absorption peak of the gas within the container.

[0050] The illustrated arrangement can be configured to perform the inspection in-line, for example by intersecting the beam with a conveyor belt along which the containers are moved.

[0051] The containers 1 may be transported on a transport band (not shown) or arranged on a carousel (not shown) for moving the containers through the detection region 4. Transport bands or carousels are known in the art for in-line use during filling and sealing of containers.

[0052] The container 1 has a certain amount of gas and may be subjected to an integrity test. If a leak occurs in the container, the gas in the container may leak into the surroundings and / or the surrounding gas may leak into the container. Thus, the concentration of the gas in the container 1, such as the absolute concentration, may change, as may the pressure in the container 1.

[0053] In the described system, the light source 6 can be, for example, a white light source transmitting a collimated light beam, or at least one laser source, such as a diode laser, a semiconductor laser, etc. The wavelength or wavelength range used for the light source is selected to match the absorption spectrum of at least one gas in the container. The detector 7 can be, for example, a photodiode, a photomultiplier tube, a CCD detector, a CMOS detector, a Si detector, an InGaAs detector, selected to be able to detect the wavelength or wavelength range of the light source. The detector 7 can also be an array, such as a position sensitive device (PSD).

[0054] The detected light may be analyzed in a control unit (not shown) to determine a characteristic of at least one gas in the vessel 1. The control unit may be a computer, microprocessor, or electronic circuitry capable of executing code, or software configured to analyze the light detected by the detector.

[0055] By detecting the at least one gas in the container 1, it is possible to determine, based on the detected transmission signal, the pressure in the container 1 and / or the concentration of the at least one gas in the container 1. The measured pressure in the container 1 and / or the concentration of the at least one gas in the container 1 can be used to determine the integrity of the container 1.

[0056] In some examples, the optical sensors 6, 7 comprise sensors based on Tunable Diode Laser Absorption Spectroscopy (TDLAS).

[0057] In some examples, the optical sensors 6, 7 consist of sensors for gas in scattering media absorption spectroscopy (GASMAS). The GASMAS technique can be used to investigate the sharp gas spectroscopic signatures, typically 10,000 times sharper than the gas spectroscopic signatures of the host material, where the gas is trapped in gaps or cavities, such as the headspace 2 of the vessel 1. GASMAS combines narrowband diode laser spectroscopy, developed for monitoring atmospheric gases, with diffuse media light propagation, well known in biomedical optics. Photons injected into the vessel 1 from a narrowband light source can be detected with a transmission or backscattering device. The technique has also been extended to remote sensing applications (LIDAR GASMAS or Multiple Scattering LIDAR). An example of a GASMAS sensor system and detection principle is described in EP10720151.9 (Svanberg et al.), which is incorporated herein by reference.

[0058] The gas sensing instrument described in EP10720151.9 consists of two diode laser drivers to monitor oxygen and water vapor in the vessel. Depending on the wavelengths used, monitoring of other gases or more than two gases is possible. The light from the multiple diode lasers (DL) is collected and split into two fibers, one used to monitor the background and the other sent to the sample. The two diode lasers can operate at wavelengths that are semi-transparent to the vessel 1, making the GASMAS technology suitable. The laser light is guided into the headspace via an optical fiber and a handheld fiber head. The scattered light emerging from the sample is acquired by a detector and the generated signal is sampled by a computer (not shown). In this example, wavelength modulation techniques are used to increase the sensitivity of the instrument by sinusoidally modulating the wavelength and examining the harmonics generated. In some examples, modulating at different frequencies allows for simultaneous detection of water vapor and oxygen.

[0059] The system 100 can assess the vessel 1 without contacting the vessel 1, and instead detect gas within the vessel from a distance. This is advantageous because the speed of detection can be increased, and is also advantageous for in-line monitoring of the vessel.

[0060] The method described in EP10720151.9 comprises emitting light from a narrowband laser source towards the container from outside the container. Measuring an absorption signal of the light scattered within the container, the absorption being caused by at least one gas within the container as the light is scattered and travels within the container. The measurement is performed outside the container and the evaluation is non-invasive to the container.

[0061] A challenge in evaluating the absorption signal obtained with the GASMAS method is that the path length of the gas interactions undergone by the light is unknown, due to light scattering within the sample.

[0062] Pathlength is important in conventional gas absorption spectroscopy for concentration quantification, as determined by the Beer-Lambert law.

[0063] Other types of GASMAS systems and methods are described in the article "Optical Analysis of Trapped Gas -Gas in Scattering Media Absorption Spectroscopy"; Svanberg, S; Laser Physics, 2010, Vol. 20, No. 1, pp. 68-77; ISSN 1054-660X, which systems and methods described therein are incorporated by reference.

[0064] For example, oxygen and water vapor can be monitored simultaneously in transmission mode. Depending on the wavelengths used, monitoring of other gases or more than two gases is possible. Alternatively, in some examples, the system 400 may be configured for backscattering measurements. A common detector is used and the two signals are separated by phase-sensitive detection of two spectroscopic signals tagged with different modulation frequencies. A partially common optical fiber path may be used. For example, the GASMAS signal recorded in the configuration as just described depends on the gas concentration in the gap or headspace, the gas, and the effective path length through the gas in a complex multiple scattering process. Therefore, the intensity of the recorded gas trace is generally expressed as the equivalent path length Leq.

[0065] Alternatively, the average path length through the scattering medium may be derived from time-resolved measurements.Delayed coincidence single-photon counting techniques may be used to obtain a histogram of photon arrival times.

[0066] In some examples, the optical sensors 6, 7 operate in a transmission mode, i.e., the optical transmitter 6 is located on one side of the detection region 4 and the optical detector 7 is located on the opposite side in the headspace 2 of the container 1, and a light beam is transmitted from the optical transmitter 6 through the container, such as the headspace 2, to the optical detector 7.

[0067] In some examples, the optical sensor is operated in reflective mode, ie, the optical transmitter is located on the same side of the container as the optical detector, and the optical detector 7 records the backscattered light from the container 1 .

[0068] In some examples, the optical transmitter 6 and the optical detector 7 are positioned at any position relative to each other on the container 1 , and the optical detector 7 records the scattered light from the container 1 .

[0069] In some examples, the light is guided to and / or from the container by optical fibers, hi some examples, the light is guided to and / or from the container through optical components including lenses, mirrors, windows, or other means of directing and directing light.

[0070] In some examples of detection area 4, such as partial enclosure 5, the distance between opposing walls on which optical sensors 6, 7 are located may have a fixed distance 9. The fixed distance 9 may be selected to allow most common sizes of containers to pass through the detection area 4. For bottles and vials, the distance 9 may be less than 10 cm, such as less than 9 cm, less than 8 cm, 5 cm, etc.

[0071] It may be advantageous if the container is close to the detector, such as less than 1 cm, as it passes through the detection area 4. This may be achieved by how the container is positioned on the transport band or carousel relative to the detection area 4, such as by a partial enclosure 5. Alternatively, in some examples of the system 100, a guide 8 may be used to position the container 1 closer to the detector 7 by guiding the container towards the detector 7.

[0072] If the properties of the contents in a vial do not match or are not within the range of expected values, the vial may be rejected using a rejection system. The rejection system may be mechanical, using a mechanical pusher to push the vial out of the transport band. Alternatively, the rejection system may use compressed air to push the vial out of the transport band.

[0073] 2 illustrates a schematic example of a measured intensity profile 200 while a closed container passes through a light beam. As the closed container passes through the light beam, a detector may detect a transmitted signal that produces an intensity profile. A portion of this intensity profile may be used to determine a characteristic of the gas within the closed container. The light beam may be pulsed and a characteristic of the gas within the container may be obtained by summing the pulses over a period of time while the laser beam is transmitted through the container.

[0074] It is therefore important to establish when to start and when to stop data collection to estimate the properties of the gas in the container. In the intensity profile 200, this period is 11 and is found between two distinct minima. The minima are obtained in the intensity profile 200 when the wall of the container passes through the light beam.

[0075] A dip (decrease) 12a and / or an increase (increase) 13a in the intensity profile may be detected to establish when to begin collecting data used to estimate the properties of the gas in the vessel. One way to find the dip 12a and / or increase 13a may be to take the derivative of the intensity. This may be done by averaging the transmitted signal from the optical sensor over time and then taking the derivative.

[0076] By knowing certain characteristics of the container, such as the speed at which the closed container advances through the light beam and the width or diameter of the portion of the container being measured, one can establish start and end points for collecting a transmitted signal used to estimate the properties of the gas within the container. For example, if a dip 12a in the intensity profile is detected, by knowing the speed of the transport band or carousel advancing the container, one can establish a start point for data collection at the rise 13a, such as near the start of the intensity period 11. By knowing the speed and width and / or diameter of the container, a stop point for data collection at the fall 12a can be established, such as a stop point near the end of the intensity period 11.

[0077] In some examples, a separate sensor may be used to measure the speed of the transport band. For example, the speed of the transport band may be measured continuously. The measured speed may be used to adjust the speed of the transport band continuously and rapidly without delay, such as to correct for fluctuations in the speed of the transport band to a preset speed. Alternatively and / or additionally, the sensor may be an encoder, and data from the encoder may be used to continuously adjust the speed value used to calculate the properties of the gas in the vial.

[0078] In this way, the same light beam can be used to both trigger and perform the measurement. Furthermore, collection and analysis of the collected data to estimate the properties of the gas in the closed vessel can be performed faster than if the entire intensity profile had to be recorded and then the intensity spectrum analyzed for the right region used for the measurement.

[0079] Alternatively, the same laser is used to both trigger and perform the measurement. A separate positioning sensor may be used to trigger the collection of data. For example, a second laser beam may be used to detect when the container enters and / or leaves the detection area.

[0080] Alternatively and / or additionally, in some examples, the descent 12a and ascent 13a may be detected by using the amplitude of the pulses in the light beam. This may indicate that the container is entering the detection area. If the pulses in the light beam are below a threshold, they are discarded. This may indicate that there is a descent 12a in the intensity profile, and an ascent 13a in the intensity profile may be indicated when the intensity increases again above the threshold. Again, by knowing the speed of the transport band or carousel advancing the container, a starting point for data collection at ascent 13a is established, as well as by knowing the speed and width or diameter of the container, a stopping point at descent 12a may also be established.

[0081] In some examples, instead of having to know the speed at which the closed container moves, both the point at which the container enters and the point at which it leaves the detection region may be determined from the intensity data. In this case, entry is established using any of the techniques previously described. The exit point may be derived by determining the drop 12b or rise 13b that represents the second minimum after the intensity period 11 of the intensity profile illustrated in FIG. 2. The second minimum may be determined using any of the techniques previously described herein.

[0082] Alternatively and / or additionally, in some examples, the dips 12a, 12b and rises 13a, 13b may be detected by using a PSD to measure the position of the light being transmitted through the detection region. This may be done by observing the deflection of the light beam as the light hitting the container wall has a different angle compared to the transmitted signal being transmitted through the container, and a minimum in the intensity profile may be established.

[0083] Additionally, in some examples, a threshold value for the pulse amplitude may be used to obtain data with a certain quality for the estimation of the properties of the gas in the closed container. If the pulse amplitude is low, the absorption characteristics will be small and therefore the information will be less. Therefore, it is preferred that the pulses used for the estimation of the properties of the gas are mainly collected during the intensity period 11. This is the period when the intensity of the transmission signal through the container is the highest.

[0084] For example, the first minimum before intensity period 11 of the intensity profile 200 is determined and the container is deemed to have entered the detection region. This means that data can be collected for the estimation of the properties of the gas in the closed container. The first collected data may not have the amplitude required to get a good estimate of the properties of the gas. Therefore, a threshold can be set and pulses with amplitudes lower than the threshold are discarded. If the container moves through the detection region, the pulse properties change and the amplitude increases. When the amplitude reaches the set threshold, intensity period 11 begins and no more pulses are discarded.

[0085] If the value of the amplitude of the pulse of the light beam falls below the set threshold, the pulse may again be ignored, which may occur when the container moves through the detection region and reaches the end of the intensity period 11. Data collection may continue until a second minimum is determined.

[0086] The threshold may also be used to ignore intensities during intensity periods 11 that are below the threshold. This may be due to, for example, dirt on the vial or irregularities in the glass wall of the vial, such as an inconsistent thickness of the glass wall of the vial.

[0087] By detecting at least two descent points 12a, 12b and / or ascent points 13a, 13b, the speed of the conveying band or carousel advancing the containers can be estimated. For example, the speed can be obtained by establishing one of the minima of the intensity profile of the descent 12a, 12b and the ascent 13a, 13b. Alternatively, the speed may be obtained by establishing a first minimum of the descent 12a or the ascent 13a and a second minimum of the descent 12b or the ascent 13b. Alternatively, the speed may be obtained by analyzing the derivative or second derivative of the intensity profile during the ascent or descent.

[0088] This can be used to monitor speed as calculations are performed and adjust for changes in speed, or to control the speed of a transport band or carousel that advances the containers.

[0089] In some examples, if the monitored speed differs from the set speed of the transport band, this may affect the accuracy of the measurement for the gas in the vial, since the portion of the container being measured may be determined using the speed of the transport band in some examples. The period over which the intensity for the calculation is acquired depends on the movement of the vial in and out of the detection region. The calculation may be corrected using the monitored speed, thus improving the accuracy of the measurement.

[0090] In some examples, if the rate differs from the set rate, the monitored rate can be set in the software so that the next vial can be analyzed based on the pre-measured rate.

[0091] Also, by establishing the first rise 13a and second fall 12b of the intensity profile, the width or diameter of the vessel may be established. This information may be used to adjust for changes in vessel size or to establish if a new type of vessel has been introduced into the system.

[0092] The intensity 10, 14 between the containers can be used to calculate the concentration of the gas in the surroundings or background. This can be, for example, the ambient air or a controlled gas composition in the detection region. This value can be averaged and used to remove or reduce offsets in the estimate of the gas concentration in a closed container if the container has a diameter that is less than the distance between the sensor's light source and detector in the detection region, or the distance between the sensor and a reflective surface opposite the sensor.

[0093] Alternatively, values ​​obtained for the gas in period 10 prior to period 11 are used to remove or reduce offsets due to ambient gas when estimating the properties of the gas in the vessel.

[0094] The intensity 10, 14 between the vessels can also be used to determine if the vessels are in phase, since the intensity 10, 14 between the vessels should be different from the intensity measured through the vessel 11. If the vessels are not in phase, measurements to estimate the properties of the gas in the closed vessel may be performed in the wrong section of the intensity profile, such as between the vessels.

[0095] 3 illustrates a schematic example of light pulses 300. Each light pulse includes an absorption peak 15a, 15b associated with the gas in the container. By weighting the pulses, pulses closer to and / or at the first rise 13a of the intensity profile and the second fall 12b of the intensity profile have less impact on the estimate of the properties of the gas in the container. Alternatively, when summing the pulses over section 11, pulses closer to and / or at the first rise 13a of the intensity profile and the second fall 12b of the intensity profile have less impact on the estimate of the properties of the gas in the container.

[0096] FIG. 4 illustrates a simplified example flow chart of a method 400 for measuring a property of a gas in a container in accordance with the present invention. The method includes: The method may include step 1001 of emitting a light beam between a light source and a detector. The light beam may be transmitted through a detection region. The light beam may have a wavelength that is tunable to match an absorption wavelength of the gas. The method may also include the step 1002 of obtaining a transmission signal from the detector associated with the light beam transmitted through the detection region. The method may also include a step 1003 of advancing the closed container toward a detection region at a predetermined speed. The method may also include a step 1004 of determining when the closed container enters the detection region based on an analysis of the transmitted signal. The method may also include step 1005 of estimating at least one characteristic of the at least one gas based on a transmission signal associated with the light beam transmitted through the closed container while the closed container advances through the detection region.

[0097] 5A illustrates a schematic carousel 500 for moving containers used to test the methods herein. Positions within the container include two vials with 0% oxygen, two vials with 2% oxygen, two vials with 20% oxygen, and two vials with air.

[0098] Figures 5B and 5C illustrate oxygen concentration measurements 600, 700 performed on containers placed in the carousel illustrated in Figure 5A. The measurements illustrate how accurate the measurements are, being able to detect the difference between a vial with 0% oxygen and a vial with 2% oxygen, as well as between a vial with 20% oxygen and a vial with air.

[0099] The present invention has been described above with reference to specific examples. However, other examples than those described above are equally possible within the scope of the present disclosure. Method steps other than those described above, implementing the method by hardware or software, may be provided within the scope of the present invention. The various features and steps of the present invention may be combined in combinations other than those described. The scope of the present disclosure is limited only by the appended claims.

[0100] The indefinite articles "a" and "an," as used herein and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one." The phrase "and / or," as used herein and in the claims, should be understood to mean "either or both" of the conjoint elements, i.e., elements that are conjunctive in some cases and disjunctive in other cases.

Claims

1. 1. A method for performing an in-line measurement to determine at least one property of a gas in a closed vessel, the closed vessel including a measurement region having a predetermined diameter, the method comprising: emitting a light beam between a light source and a detector, the light beam being transmitted through a detection region, the light beam having a wavelength tunable to an absorption wavelength of the gas; obtaining a transmission signal from the detector related to the light beam transmitted through the detection region; advancing the closed container toward the detection area at a predetermined speed; determining when the closed container enters the detection area based on an analysis of the transmitted signal; and estimating at least one property of at least one gas based on the transmission signal associated with the light beam transmitted through the measurement region of the closed container while the closed container is advancing through the detection region.

2. The method of claim 1 , wherein the transmission signal is obtained continuously.

3. 10. The method of claim 1, wherein the light beam is used to both determine when the closed container enters the detection region and to estimate the at least one characteristic of the gas within the closed container.

4. The method of claim 1 , wherein the at least one characteristic of the gas comprises at least one of a gas pressure within the closed container and / or a concentration of the gas within the closed container.

5. The method of claim 1 , wherein the transmission signal is used to determine an increase and / or decrease in the intensity of the transmission signal due to the closed container entering and / or exiting the detection area.

6. The method of claim 5 , wherein a derivative of the intensity is used to determine the rise and / or fall of the intensity of the transmitted signal.

7. 6. The method of claim 5, wherein the light beam is pulsed, each pulse having a predetermined amplitude, and the amplitude of the pulses is used to determine the rise and / or fall of the intensity of the transmitted signal.

8. 2. The method of claim 1, wherein the detector is a PSD and the transmitted signal is used to determine a deflection of the light beam to detect when the closed container enters and / or exits the detection area.

9. 9. The method of claim 8, wherein the deflection is used to determine an increase and / or decrease in the intensity of the transmitted signal due to the closed container entering and / or exiting the detection region.

10. The method of claim 1 , wherein the velocity is used in conjunction with the transmitted signal to determine a start point and / or an end point for estimating the at least one characteristic.

11. The method of claim 10, wherein the start point and / or the end point are set to a predetermined period based on the velocity after it is determined that the closed container has entered the detection area based on the transmission signal.

12. The method of claim 10 , wherein the diameter of the measurement area of ​​the closed container is used to determine the endpoint.

13. 6. The method of claim 5, wherein the time measured between two of the descents and / or ascents determined based on the strength of the transmission signal is used to estimate the velocity and / or the diameter of the measurement area of ​​the closed container.

14. The method of claim 1 , wherein the measurement area of ​​the closed container is a portion of a headspace.

15. The method of claim 1 , wherein the transmitted signal is used to determine a background concentration of the gas when the closed container is not within the detection region.

16. 16. The method of claim 15, wherein the background concentration of the gas is used to remove an offset when performing an estimation of the property of the gas in the closed vessel.

17. 1. A system for performing in-line measurements to determine at least one characteristic of a gas in a closed vessel, the closed vessel including a measurement area having a predetermined diameter, the system comprising: an optical sensor configured to emit a light beam between a light source and a detector, the light beam being transmitted through a detection region, the light beam having a wavelength tunable to an absorption wavelength of the gas; the optical sensor is configured to obtain a transmission signal associated with the light beam, and the system further comprises: means for advancing the closed container toward the detection area at a predetermined velocity; a control unit configured to determine when the closed container enters the detection area based on an analysis of the transmitted signal; the control unit is further configured to estimate at least one property of at least one gas based on the transmission signal associated with the light beam transmitted through the measurement region of the closed container while the closed container advances through the detection region.

18. The system of claim 17, wherein the system is configured to perform the steps of the method of any one of claims 2 to 16.

Images