Station and method for measuring suspended molecular contaminants

Abstract

The invention relates to a measurement station (1) for measuring suspended molecular contaminants, comprising:-at least one gas analyzer (3) configured to measure the concentration of at least one contaminant,-a plurality of air inlets (5) configured to be in fluid communication with said gas analyzer (3) and configured to be connected to a respective plurality of sampling lines (7), -a plurality of first controllable isolation valves (11) interposed between the plurality of air inlets (5) and the gas analyzer (3),-a control unit (15) configured to control the opening or closing of the first controllable isolation valves (11) so that the gas analyzer (3) is in fluid communication with at least one sampling line (7), wherein the control unit (15) is further configured to instruct verification of the accuracy of the analyzer (3) when the analyzer (3) detects that the pollutant concentration is greater than a predetermined threshold.

Description

Technical Field

[0001] The present invention relates to a measuring station for measuring suspended molecular contaminants, in particular for monitoring molecular contaminants in the environment of a clean room, such as a clean room in a semiconductor manufacturing plant, and also to a method for detecting suspended molecular contaminants by means of such a measuring station. Background Art

[0002] In the semiconductor manufacturing industry, substrates such as semiconductor wafers or photomasks must be protected from suspended molecular contaminants / airborne molecular contaminants (or AMCs) in order to prevent them from damaging the electronic circuits of the wafers or substrates. To this end, the wafers are placed in shipping and storage boxes, allowing the wafers to be transported from one piece of equipment to the next, or stored between two manufacturing steps. In addition, the shipping boxes and multiple pieces of equipment are arranged in a clean room where the contaminant levels are controlled and the temperature, humidity and pressure are maintained at precise and stable levels.

[0003] In a cleanroom, gaseous species in suspension may have different sources and properties, such as acids, bases, alcohols, condensable elements, doping elements, etc. These molecules may originate from the air inside the semiconductor manufacturing facility or from the outgassing of wafers after manufacturing operations.

[0004] Gas analyzers present in cleanrooms provide real-time assessment of the concentration of suspended gaseous substances, especially humidity. The measured concentrations are sometimes very low, in the ppm level or down to sub-ppb levels.

[0005] Since these gas analyzers measure the surrounding gas atmosphere, they need to be provided in each area of ​​the cleanroom to be tested.

[0006] The number of gaseous substances to be measured and the number of test zones need to be increased to reduce the risk of substrate contamination. However, doubling the number of analyzers per zone and the number of these zones to be tested quickly makes this solution very costly.

[0007] In order to reduce costs, a measuring unit combining different analyzers has been proposed. The unit is provided with a plurality of input ports, each input port being directed to a specific test area of ​​the clean room via a sampling line.

[0008] However, due to the different lengths of the sampling lines and the potentially low concentrations of contaminants, erroneous measurements can occur, especially false positives can be detected. These false positives can cause the manufacturing of semiconductors to stop and require operators to intervene in the area where the contaminant was detected. This can incur high costs.

[0009] Therefore, it is necessary to find a solution that can reduce or avoid false positives and improve the reliability of contaminant detection. Summary of the invention

[0010] One of the objects of the present invention is to propose a measuring station and a measuring method which at least partially overcome one of the above-mentioned disadvantages.

[0011] To this end, a subject of the invention is a measuring station for measuring suspended molecular contaminants, comprising:

[0012] - at least one gas analyzer configured to measure the concentration of at least one pollutant,

[0013] - a plurality of air inlets configured to be in fluid communication with the gas analyzer and configured to be connected to one or more sampling lines,

[0014] - a plurality of first controllable isolation valves interposed between the plurality of air inlets and the gas analyzer,

[0015] a control unit configured to control the opening and closing of the first controllable isolation valve so as to place the gas analyzer in fluid communication with at least one sampling line,

[0016] Wherein, the control unit is further configured to: when the analyzer detects that the pollutant concentration is greater than a predetermined threshold, instruct to verify the accuracy of the analyzer.

[0017] By verifying the accuracy of the analyzer when a contaminant concentration greater than a predetermined threshold is measured, the number of inappropriate contaminant detections can be limited, simplifying the management of cleanroom contaminants.

[0018] According to another aspect of the present invention, the measuring station also includes a reservoir and an additional valve arranged between the reservoir and the gas analyzer, the reservoir containing a reference fluid having a predetermined concentration of one or more pollutants to be monitored, and the control unit is configured to: during the accuracy verification of the analyzer, control the opening of the additional valve and instruct the measurement of the concentration of one or more pollutants in the reservoir.

[0019] The accuracy verification can be achieved by injecting a clean fluid or gas (free of contaminants) or a reference fluid or gas (the reference gas may contain one or more compounds) having a controlled (known) concentration of one or more contaminants. The reference fluid or gas may come from a permeation tube, which may or may not be heated. The measurement station may also include a device for diluting the reference fluid or gas, which is configured to obtain a reference fluid or gas from the reference gas in the reservoir 17, which contains one or more contaminants at different corresponding concentrations.

[0020] According to another aspect of the present invention, the measuring station further comprises:

[0021] a first reservoir containing a fluid having a predetermined concentration of one or more contaminants to be monitored, and a first additional valve associated with a first mass flow meter and used to control the establishment of fluid communication between the first reservoir and the analyzer,

[0022] a second reservoir containing a fluid free of contaminants to be monitored and a second additional valve, the second additional valve being associated with a second mass flow meter and being used to control the establishment of fluid communication between the second reservoir and the analyser,

[0023] The control unit is configured to: during accuracy verification of the analyzer, control opening of one of the first additional valve or the second additional valve, instruct the analyzer to measure the pollutant concentration in one of the first reservoir or the second reservoir, control closing of the first additional valve or the second additional valve, control opening of the other of the first additional valve or the second additional valve, instruct the analyzer to measure the pollutant concentration in the other of the first reservoir or the second reservoir, compare the measured value with a predetermined pollutant concentration, and verify whether the difference between the measured value and the predetermined concentration is lower than a predetermined maximum difference.

[0024] According to another aspect of the invention, the control unit may be configured to instruct the measurement of the concentration in the first reservoir before measuring the concentration in the second reservoir. Other concentrations may also be obtained using two reservoirs by diluting the pollutants in the first reservoir with gas from the second reservoir; the required dilution may be performed using mass flow meters associated with the first and second reservoirs.

[0025] According to another aspect of the invention, the control unit is configured to: issue and / or send an alarm signal if the analyzer whose accuracy has been verified detects a pollutant concentration greater than a predetermined threshold value. The alarm signal is for example sent to a remote server, such as a client server.

[0026] According to another aspect of the present invention, the measuring station may include a plurality of analyzers arranged in parallel, and a plurality of second controllable isolation valves interposed between the plurality of air inlets and the corresponding plurality of analyzers to control the establishment of fluid communication between the analyzers and the air inlets.

[0027] According to another aspect of the invention, the control unit is configured to control opening and closing of the first and second controllable isolation valves to establish fluid communication between the sampling line and the analyzer sequentially and / or simultaneously according to a predetermined sequence.

[0028] According to another aspect of the present invention, the control unit is configured to instruct verification of the accuracy of certain analyzers only when the analyzers detect that the pollutant concentration is greater than a predetermined threshold.

[0029] According to another aspect of the present invention, the control unit is configured to: issue and / or send an alarm signal when detecting that the pollutant concentration is greater than a predetermined threshold, and initiate accuracy verification. The alarm signal is for example sent to a remote server, such as a client server.

[0030] According to another aspect of the invention, the air inlet comprises means for regulating the air flow rate so that the delivery through the different sampling lines connected to the air inlet is the same regardless of the length and / or diameter of the different sampling lines.

[0031] According to another aspect of the invention, the means for regulating the air flow is a valve with a microleakage, that is to say a valve which allows the flow to be regulated in a precise manner.

[0032] According to another aspect of the invention, during verification of the accuracy of the analyzer, if the difference between the determined concentration value and the predetermined concentration is greater than a predetermined maximum difference, the control unit is configured to instruct recalibration of the analyzer.

[0033] The present invention also relates to a method for detecting suspended molecular contaminants using a measuring station, the measuring station comprising a gas analyzer and a plurality of air inlets, the plurality of air inlets being configured to be in fluid communication with the gas analyzer and being configured to be connected to one or more sampling lines, the method comprising the following steps:

[0034] - establishing fluid communication between the sampling lines associated with the air inlet and the analyzer, and then measuring the concentration of one or more pollutants to be monitored in the sampling lines, the sampling lines being sequentially placed in fluid communication with the analyzer in order to measure the concentration of pollutants in different sampling lines,

[0035] - When the measured value of the pollutant concentration exceeds a predetermined threshold, verifying the accuracy of the analyzer.

[0036] According to another aspect of the present invention, when the accuracy of the analyzer is verified, the measuring station issues an alarm signal or sends an alarm signal to a remote server.

[0037] According to another aspect of the invention, the measurement station comprises a plurality of analyzers allowing the measurement of one pollutant or a group of pollutants and the plurality of analyzers are simultaneously in fluid communication with the sampling line.

[0038] According to another aspect of the present invention, the step of verifying the accuracy of the analyzer includes: establishing fluid communication between the analyzer and a first reservoir containing a fluid having a predetermined concentration of a contaminant to be monitored, and measuring the concentration by the analyzer, and then establishing fluid communication between the analyzer and a second reservoir containing a fluid without the contaminant to be monitored, and measuring the concentration by the analyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Other characteristics and advantages of the invention will become more apparent on reading the following description, given by way of illustrative and non-limiting examples, and the accompanying drawings, in which:

[0040] [ Figure 1 ] is a schematic diagram of a measurement station and associated sampling pipelines according to a first embodiment;

[0041] [ Figure 2 ] is a schematic diagram of a measurement station and related sampling pipelines according to a second embodiment;

[0042] [ Figure 3 ] is a schematic diagram of a measurement station and related sampling pipelines according to a third embodiment;

[0043] [ Figure 4a ] is a schematic diagram of a reservoir associated with an analyzer according to a first embodiment;

[0044] [ Figure 4b ] is a schematic diagram of a reservoir associated with an analyzer according to a second embodiment;

[0045] [ Figure 5 ] is a flow chart of the steps of a method for detecting suspended molecular contaminants using a measuring station.

[0046] In the figures, identical elements have the same reference numerals. DETAILED DESCRIPTION

[0047] The following embodiments are examples. Although the specification mentions one or more embodiments, this does not necessarily mean that each mention refers to the same embodiment or that these features apply to a single embodiment. The individual features of different embodiments may also be combined or interchanged to provide other embodiments.

[0048] The invention relates to a station for measuring suspended molecular contaminants. Figure 1 is a schematic diagram of such a measuring station 1. The measuring station 1 comprises a plurality of gas analyzers 3, in this case three. Each analyzer 3 can be configured to measure the concentration of a predetermined pollutant or a group of predetermined pollutants. The measuring station 1 further comprises a plurality of air inlets 5, in this case four, which are configured to be placed in fluid communication with the gas analyzers 3. The fluid communication between the air inlets 5 and the gas analyzers 3 is achieved, for example, by a pipeline. The air inlets 5 are configured to be connected to one or more sampling lines 7, in particular each air inlet 5 corresponds to a sampling line 7, such as Figure 1 (however, one air inlet 5 can be connected to multiple sampling lines 7). The ends of the sampling lines on the opposite sides of the air inlet 5 constitute sampling points 9. The sampling points 9 are distributed in different areas of the clean room, for example.

[0049] In order to limit the influence of the length of the sampling lines 7 on the measurement results of the analyzer 3, the air inlet 5 may include means for regulating the air flow. These means for regulating the air flow are configured so that the delivery volume through the different sampling lines 7 is the same, regardless of their length. These means for regulating the air flow are, for example, valves with a micro-leakage, which make it possible to ensure that the flow rate is the same for all sampling lines, regardless of their length and / or diameter.

[0050] The measuring station 1 further comprises a plurality of first controllable isolation valves 11, which are respectively inserted between the plurality of air inlets 5 and the gas analyzers 3, so as to allow or prevent fluid communication between the air inlets 5 and the gas analyzers 3. The first controllable isolation valves 11 may be implemented by a multiplex valve, which allows or prevents fluid communication between one or more air inlets 5 and one or more gas analyzers 3. The measuring station 1 further comprises a regulating pump 13, which is configured to draw air from the sampling line 7 to the gas analyzers 3. The regulating pump 13 is connected to the air inlet 5, for example, via a pipeline. As an alternative, the regulating pump 13 may be placed downstream of the first controllable isolation valve 11, such as Figure 2 In this embodiment, at least one controllable isolation valve 11 may be opened to ensure the normal operation of the regulating pump 13. As another alternative, multiple second controllable isolation valves 11' may be arranged at the inlet of each analyzer 3, such as Figure 3 , in order to select the analyzer 3 to be connected to the air inlet 5. When the position of the adjustment pump 13 is as shown Figure 1 As shown in the embodiment of FIG. 1 , these second controllable isolation valves 11 ′ can also be used. The analyzer 3 can also include its own suction device, such as an internal sampling pump. In this case, it is not necessary to use the regulating pump 13.

[0051] The measuring station 1 further comprises a control unit 15. The control unit 15 comprises, for example, a microcontroller or a microprocessor. The control unit 15 is configured to control the opening or closing of the first isolation valve 11 and / or the second isolation valve 11' so as to establish or not establish fluid communication between the gas analyzer 3 and the sampling line 7, so as to be able to analyze the air from different sampling points 9. The sampling lines 7 can be in fluid communication state successively in a predetermined order. Some sampling lines 7 can also be in fluid communication with the gas analyzer 3 at the same time, so as to analyze the air from multiple sampling points 9 at the same time.

[0052] The control unit 15 is also connected to the regulating pump 13 and the analyzer 3. The control unit 15 is also configured to instruct verification of the accuracy of the gas analyzer 3 when the gas analyzer 3 detects that the concentration of pollutants is greater than a predetermined threshold value, so as to avoid false detection of pollutants.

[0053] To verify, Figure 4a As shown, the measuring station 1 also includes: a first reservoir 17 associated with the analyzer 3; a first additional valve 21 and a first flow meter 24 arranged between the first reservoir 17 and the analyzer 3 (the first additional valve 21 and the first flow meter 24 can be combined into a single device, corresponding to a mass flow controller); a second reservoir 19 associated with the analyzer 3; a second additional valve 23 and a second flow meter 26 arranged between the second reservoir 19 and the analyzer 3 (the second additional valve 23 and the second flow meter 26 can be combined into a single device, corresponding to a mass flow controller). The first reservoir 17 and the second reservoir 19 are, for example, cylinders containing pressurized gas. According to Figure 4b In the alternative embodiment shown, the reservoirs 17 , 19 are not fluidly connected to a pipeline comprising an isolation valve 11 in order to avoid contamination of the sampling line by contaminants contained in the first reservoir 17 .

[0054] The first reservoir 17 contains a fluid having a first predetermined concentration of one or more pollutants to be monitored, such as benzene, which predetermined concentration may be between 1-100 ppb. The second reservoir 19 contains a fluid having a second predetermined concentration of a pollutant to be monitored, in particular, the second predetermined concentration may be zero, so that the fluid in the second reservoir 19 is free of pollutants and contains, for example, clean air. The contents of the second reservoir 19 can thus be used to dilute the pollutants contained in the first reservoir 17 so that a number greater than two different predetermined concentrations can be obtained using only two reservoirs. Multiple reservoirs containing different predetermined concentrations of pollutants can also be used.

[0055] In practice, a first reservoir 17 and a second reservoir 19 are associated with each analyser 3. A number of reservoirs 17, 19 greater than two may be associated with one analyser 3, wherein different reservoirs 17, 19 have different predetermined concentrations.

[0056] As an alternative, the measuring station 1 may also include a single reservoir 17 and an additional valve 21 disposed between the reservoir 17 and the gas analyzer 3, the reservoir 17 containing a reference fluid having a predetermined concentration of one or more pollutants to be monitored, the control unit 15 being configured to: during verification of the accuracy of the analyzer 3, control the opening of the additional valve 21 and command the concentration of the one or more pollutants in the measuring reservoir 17. The measuring station 1 may also include a device for diluting a reference fluid or gas, the device being configured to obtain a reference fluid or gas from the reference gas in the reservoir 17, which contains one or more pollutants of different respective concentrations.

[0057] Verification of accuracy can be achieved by injecting a clean fluid or gas (free of contaminants) or a reference fluid or gas (the reference gas may contain one or more compounds) with a controlled (known) concentration of one or more contaminants. The reference fluid or gas may also come from a permeation tube, which may or may not be heated.

[0058] Therefore, when the analyzer 3 detects a concentration greater than a predetermined threshold, the control unit 15 instructs to perform an accuracy verification of the analyzer 3. In practice, such an automatic verification may be performed for certain analyzers 3. Furthermore, the concentration measurement may be repeated in order to verify whether the predetermined threshold has been exceeded before initiating the accuracy verification of the analyzer 3.

[0059] This verification includes: a first step, by opening the first additional valve 21 and closing the other valves 11, 23 located on the pipeline connected to the analyzer 3, the concentration of the fluid contained in the first reservoir 17 is measured by means of the analyzer 3; a second step, by opening the second additional valve 23 and closing the other valves 11, 21 located on the pipeline connected to the analyzer 3, the concentration of the fluid contained in the second reservoir 19 is measured by means of the analyzer 3. The control unit 15 is also configured to compare the value measured by the analyzer 3 with the predetermined concentration. If the difference between the measured value and the predetermined concentration is lower than the predetermined maximum difference, the analyzer 3 is considered to be reliable, that is, the accuracy is verified, and the detection of pollutants is confirmed. The predetermined maximum difference can be selected by the user and input, for example, via an interface (such as a touch screen or a control button) linked to the control unit 15. The second reservoir can also be used to dilute the concentration of the first reservoir (for example, when the second reservoir is clean air, the second reservoir is used to dilute the first reservoir). Thus, the two additional valves 21 and 23 can be opened at the same time so that different concentrations can be delivered. The different predetermined concentrations can then be transmitted to the analyzer 3 in sequence to verify its accuracy.

[0060] The control unit 15 is then configured to emit an alarm signal, such as a visual and / or acoustic signal, or to send an alarm signal, such as to a remote server.

[0061] Furthermore, a first alarm signal may be issued prior to the verification of the analyzer 3 to indicate that the analyzer 3 has detected a contaminant concentration greater than a predetermined threshold value and that verification of the analyzer 3 is to be initiated.

[0062] On the contrary, if during the verification of the accuracy of the analyzer 3, the difference between the measured value and the predetermined concentration is greater than a predetermined maximum difference, the analyzer 3 is considered unreliable and therefore the detection of the contaminant cannot be confirmed. The control unit 15 is then configured to initiate a recalibration of the analyzer 3. As an alternative, the control unit 15 can issue an alarm signal to indicate the verification result and allow the operator to decide on the measures to be taken. Furthermore, as a second step, by measuring the fluid free of contaminants located in the second reservoir 19, the subsequent measurements performed by the analyzer 3 are not distorted. In fact, the use of a gas free of contaminants makes it possible to purge the analyzer 3 and even the pipelines in the vicinity of the analyzer 3.

[0063] The invention also relates to a method for detecting suspended molecular contaminants using a measuring station 1 as described above.

[0064] Figure 5 A flow chart showing the steps of the method is shown. The order of the steps or sub-steps may be different from the order presented, and some steps or sub-steps may be performed simultaneously.

[0065] The first step 101 involves establishing fluid communication between one or more sampling lines 7 associated with different air inlets 5 and one or more analyzers 3. The control unit 15 establishes the fluid communication by controlling the opening or closing of different valves 11, 11' of the measuring station 1.

[0066] The second step 102 involves measuring, by one or more analyzers 3, the concentration of one or more pollutants to be monitored in one or more sampling lines 7 in fluid communication with the one or more analyzers 3. If multiple analyzers 3 are used, each analyzer 3 may be configured to measure the concentration of a different pollutant or group of pollutants than the other analyzers 3.

[0067] The third step 103 involves comparing the pollutant concentration value determined by the analyzer 3 with a predetermined threshold value set by the user. Different threshold values ​​associated with different actions or different alarms may be defined in order to better assess the level of pollutants.

[0068] Steps 101 to 103 are repeated according to a predetermined sequence so that different air inlets 5 (and therefore different sampling lines 7) are sequentially fluidly connected to one or more analyzers 3, and a plurality of air inlets 5 may be simultaneously fluidly connected to the one or more analyzers 3. Before passing to the next configuration of the valves 11, 11', for each configuration of the valves 11, 11', the pollutant concentration is measured and compared with a predetermined threshold value.

[0069] When the measured value of the pollutant concentration exceeds a predetermined threshold, the control unit 15 initiates a procedure for verifying the accuracy of the analyzer 3 , corresponding to step 104 .

[0070] This step 104 comprises a first sub-step 1041 which involves closing the valves 11, 11' of the pipes connected to the analyser 3 whose accuracy is being verified and opening the first additional valve 21 associated with this analyser 3. A second sub-step 1042 involves measuring the concentration of pollutants in the first reservoir 17 by the analyser 3. A third sub-step 1043 involves closing the first additional valve 21 and opening the second additional valve 23. A fourth sub-step 1044 involves measuring, by the analyser 3, the concentration of pollutants in the second reservoir 19, or the concentration of pollutants mixed between the first reservoir 17 and the second reservoir 19 at a predetermined dilution ratio. A fifth sub-step 1045 involves comparing the value determined by the analyser 3 with the expected concentration of pollutants in the first reservoir 17 and the second reservoir 19, or with the expected concentration of pollutants of a gas mixture from the two reservoirs 17 and 19 with a predetermined dilution of the concentration of the first reservoir 17 with the second reservoir 19, and comparing these differences with a predetermined maximum permissible difference. If the difference is below the maximum allowed difference, the measurement of the analyser 3 may be considered reliable and confirm that the concentration value of the pollutant measured in step 102 is greater than a predetermined threshold, and the method continues to step 105 where an alarm may be issued indicating the pollutant concentration.

[0071] One or more new measurements may also be made on the sampling lines 7 where concentrations greater than a predetermined threshold have been measured to confirm the first measurement. These new measurements may also be made in areas adjacent to the areas where the contaminants have been detected. If contaminants are detected simultaneously in multiple sampling lines 7 being analyzed, new measurements may be made on one of the sampling lines 7 to improve the determination of the extent of the contaminated area.

[0072] As an alternative, it is also possible to first measure the pollutant concentration in the second reservoir 19 (or a mixture of both reservoirs 17, 19) and then measure the pollutant concentration in the first reservoir 17. It is also possible to use multiple reservoirs 17 containing different pollutants or different concentrations of pollutants.

[0073] If the difference between the measured value and the predetermined concentration is greater than the maximum allowed difference, the measurement of the analyser 3 may be considered unreliable and the method continues to step 106 where a recalibration of the analyser 3 may be requested and an alarm may be issued indicating that the analyser 3 is unreliable.

[0074] By verifying the accuracy of the analyzer 3 when the analyzer 3 measures a contaminant concentration greater than a predetermined threshold, the number of false detections can be reduced without having to verify the accuracy of each measurement by the analyzer 3. Specifically, a measurement takes several minutes, such as five minutes, while the accuracy verification may take tens of minutes, such as 20 minutes. Therefore, the contaminant management of the clean room is less restricted (due to the reduction in the number of false detections) because the detection of contaminants usually results in operator intervention to analyze the source of the contaminant and remedy such contamination.

Claims

1. A measuring station (1) for measuring suspended molecular contaminants, include: - at least one gas analyzer (3) configured to measure the concentration of at least one pollutant, - a plurality of air inlets (5) configured to be in fluid communication with the gas analyzer (3) and to be connected to one or more sampling lines (7), - a plurality of first controllable isolation valves (11), which are interposed between the plurality of air inlets (5) and the gas analyzer (3), a control unit (15) configured to control the opening and closing of the first controllable isolation valve (11) so as to place the gas analyzer (3) in fluid communication with at least one sampling line (7), It is characterized in that the control unit (15) is also configured to: when the analyzer (3) detects that the pollutant concentration is greater than a predetermined threshold, the control unit (15) instructs verification of the accuracy of the analyzer (3).

2. The measuring station according to claim 1 further comprises a reservoir (17) and an additional valve (21) arranged between the reservoir (17) and the gas analyzer (3), wherein the reservoir (17) contains a reference fluid having a predetermined concentration of one or more pollutants to be monitored, and the control unit (15) is configured to: during verification of the accuracy of the analyzer (3), the control unit (15) controls the opening of the additional valve (21) and instructs the measurement of the concentration of one or more pollutants in the reservoir (17).

3. The measuring station (1) according to claim 1 or 2, further comprising: include: a first reservoir (17) containing a fluid having a predetermined concentration of one or more contaminants to be monitored; a first additional valve (21), the first additional valve (21) being associated with a first mass flow meter (24) and being used to control the establishment of fluid communication between the first reservoir (17) and the analyzer (3); a second reservoir (19), the second reservoir (19) containing a fluid free of contaminants to be monitored; a second additional valve (23), the second additional valve (23) being associated with a second mass flow meter (26) and being used to control the establishment of fluid communication between the second reservoir (19) and the analyzer (3), the control unit (15) being configured such that during verification of the accuracy of the analyzer (3), the control unit (15) 5) Controlling to open one of the first additional valve or the second additional valve (21, 23), instructing the analyzer (3) to measure the pollutant concentration in one of the first reservoir or the second reservoir (17, 19), controlling to close the first additional valve or the second additional valve (21, 23), controlling to open the other of the first additional valve or the second additional valve (21, 23), instructing the analyzer (3) to measure the pollutant concentration in the other of the first reservoir or the second reservoir (17, 19), comparing the measured value with a predetermined pollutant concentration, and verifying whether the difference between the measured value and the predetermined concentration is lower than a predetermined maximum difference.

4. The measuring station (1) according to claim 3, in, The control unit (15) is configured to instruct the measurement of the concentration in the first reservoir (17) before measuring the concentration in the second reservoir (19).

5. The measuring station (1) according to any one of the preceding claims, in, The control unit (15) is configured to issue an alarm signal when the analyzer (3) whose accuracy has been verified detects that the concentration of pollutants is greater than a predetermined threshold.

6. A measuring station (1) according to any one of the preceding claims, comprising a plurality of analyzers (3) arranged in parallel, and a plurality of second controllable isolation valves (11'), wherein the plurality of second controllable isolation valves (11') are inserted between the plurality of air inlets (5) and the corresponding plurality of analyzers (3) so as to control the establishment of fluid communication between the analyzers (3) and the air inlets (5).

7. The measuring station (1) according to the preceding claim, in, The control unit (15) is configured to control the opening and closing of the first and second controllable isolation valves (11, 11') so as to establish fluid communication between the sampling line (7) and the analyzer (3) sequentially and / or simultaneously according to a predetermined sequence.

8. The measuring station (1) according to claim 6 or 7, in, The control unit (15) is configured to instruct verification of the accuracy of the analyzer (3) only for certain analyzers (3) when the analyzer (3) detects that the pollutant concentration is greater than a predetermined threshold.

9. The measuring station (1) according to any one of the preceding claims, in, The control unit (15) is configured to send out an alarm signal and initiate accuracy verification when it is detected that the pollutant concentration is greater than a predetermined threshold.

10. The measuring station (1) according to any one of the preceding claims, in, The air inlet (5) comprises means for regulating the air flow rate so that the delivery through the different sampling lines (7) connected to the air inlet (5) is the same, regardless of the length and / or diameter of the sampling lines (7).

11. The measuring station (1) according to the preceding claim, in, The device for regulating the air flow is a valve with a slight leakage.

12. The measuring station (1) according to any one of the preceding claims, in, If the difference between the determined concentration value and the predetermined concentration is greater than a predetermined maximum difference, the control unit (15) is configured to instruct recalibration of the analyzer (3).

13. A method for detecting suspended molecular contaminants using a measuring station (1), the measuring station (1) comprising a gas analyzer (3) and a plurality of air inlets (5), the plurality of air inlets (5) being configured to be in fluid communication with the gas analyzer (3) and to be connected to one or more sampling lines (7), the method The following steps are involved: - establishing fluid communication in sequence between a sampling line (7) associated with the air inlet (5) and the analyzer (3), and measuring the concentration of one or more pollutants to be monitored in the sampling line (7), - Verifying the accuracy of the gas analyzer (3) when the measured value of the pollutant concentration exceeds a predetermined threshold.

14. The detection method according to the preceding claim, in, When the accuracy of the gas analyzer (3) is verified, an alarm signal is issued and / or sent to a remote server.

15. The detection method according to claim 13 or 14, in, The measuring station (1) comprises a plurality of gas analyzers (3) associated with a pollutant or a group of pollutants, and wherein the plurality of gas analyzers (3) are simultaneously in fluid communication with the sampling line (7).

16. The detection method according to any one of claims 13 to 15, in, The step of verifying the accuracy of the gas analyzer (3) comprises establishing fluid communication between the gas analyzer (3) and a first reservoir (17) containing a fluid having a predetermined concentration of a pollutant to be monitored, and measuring the concentration by means of the analyzer (3), and then establishing fluid communication between the analyzer (3) and a second reservoir (19) containing a fluid without the pollutant to be monitored, and measuring the concentration by means of the analyzer (3).

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