JP2023088420A - Analyzer, Hazardous Material Detector, and Selection Screen Interface - Google Patents

Abstract

To solve a problem in which stable discharge is not achieved when an electrode used for ionization has been deteriorated.SOLUTION: An analyzer includes an ionization unit 10 that ionizes a sample using discharge between electrodes 12a and 12b, a detection unit 13 that detects and analyzes the ionized sample, and a control unit 14 that monitors a current flowing through the electrode 12a or 12b or a voltage applied to the electrode 12a or 12b, or the discharge state by the mass spectrum obtained by the detection unit 13 at the start of the discharge when the discharge is started from the state where the discharge is stopped, and that adjusts a discharge voltage required to generate discharge by the electrodes 12a and 12b on the basis of the results of monitoring the discharge state.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an analyzer for analyzing substances adhering to an object to be inspected, a dangerous substance detection device, and a selection screen interface.

The threat of terrorism is increasing worldwide, and the demand for terrorism countermeasures using dangerous materials such as explosives is expanding in important facilities such as power plants. Along with this, the demand for dangerous substance detection devices is increasing. Many trace-type dangerous substance detection devices have an analyzer for analyzing substances inside, and it is necessary to periodically replace consumables in order to maintain the soundness of the dangerous substance detection device. Therefore, it is desired to reduce running costs by prolonging the life of consumables.

For example, in the case of a trace-type hazardous substance detection device equipped with an analyzer that uses mass spectrometry technology, fine particles collected from an object to be inspected are ionized, and the molecular weight of the ionized fine particles is used to determine whether the substance is a hazardous substance or not. there is Ionization is performed by corona discharge or the like.

In Patent Document 1, ``The gas and/or fine particles of the substance to be detected adhering to the test object are separated by an air flow from the air supply unit, the separated sample is sucked from the suction port, and concentrated in the fine particle collection unit. A hazardous material detector is disclosed in which ions are collected, sample ions are generated in an ion source, and mass analyzed in a mass spectrometer.

JP 2017-223482 A

By the way, an insulating oxide film is formed on the surface of an electrode for discharging with the lapse of time. Oxide films formed on the electrodes may cause the discharge to become unstable. The formation speed of the oxide film varies depending on the installation environment of the electrode, and in the worst case, discharge cannot be performed and analysis cannot be performed. In order to prevent this phenomenon, it is important not to form an oxide film. Therefore, even when an oxide film is formed, a technique for stabilizing the discharge is required.

In Patent Document 1, it is considered that ions are generated by using electric discharge, but there is no mention of the phenomenon and countermeasures when an oxide film is formed. Therefore, it is thought that the dangerous substance detection device disclosed in Patent Document 1 also has a shortened electrode life due to the formation of an oxide film on the electrode that causes discharge during ionization, as in a general dangerous substance detection device. In addition, since an oxide film is formed on the surface of the electrode and the discharge becomes unstable, maintenance of the electrode is required. As a result, running costs increase.

In view of the above situation, there has been a demand for a method of realizing stable discharge even when the electrodes used for ionization have deteriorated.

In order to solve the above problems, an analyzer of one embodiment of the present invention includes an ionization section that ionizes a sample using discharge between electrodes, a detection section that detects and analyzes the ionized sample, and a discharge stop. When the discharge is started from the discharged state, the discharge state is monitored by the current flowing in the electrode or the voltage applied to the electrode, or the mass spectrum obtained by the detection unit at the start of the discharge, and based on the monitoring result of the discharge state, the electrode and a control unit that adjusts the discharge voltage required to generate the discharge by.

In addition, the dangerous substance detection device of one embodiment of the present invention includes a mechanism for collecting a sample from an object to be inspected, an ionization unit for ionizing the sample using discharge between electrodes, and a detection unit for detecting and analyzing the ionized sample. When the discharge is started from the state where the discharge is stopped, the discharge state is monitored by the current flowing through the electrode or the voltage applied to the electrode, or the mass spectrum obtained by the detection unit at the start of the discharge. a controller for adjusting the discharge voltage required to generate a discharge by the electrodes based on the results.

Further, a selection screen interface according to one aspect of the present invention is a selection screen interface used in a dangerous substance detection device that detects a dangerous substance by detecting an ionized sample using discharge between electrodes, and selects an electrode. and an area displaying the replacement status and the next replacement time of the electrode corresponding to the selected button.

According to at least one aspect of the present invention, since the electrode used for ionization is monitored in the analysis section and the discharge voltage is adjusted, stable discharge can be achieved even when the electrode is deteriorated.
Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a diagram showing a configuration example of a control system of a dangerous substance detection device having an ionization section that performs corona discharge according to a first embodiment of the present invention; FIG. It is a figure which shows the structural example of the hardware of the control system with which the analysis part of the dangerous substance detection apparatus is provided. 4 is a flow chart showing an outline of processing by a control unit during a voltage adjustment mode according to the first embodiment of the present invention; 4 is a flow chart showing an example of a procedure of processing when a control unit according to the first embodiment of the present invention executes a voltage adjustment function; FIG. 9 is a flow chart showing an example of a procedure of processing when a control unit according to a second embodiment of the present invention executes a needle current monitoring function; FIG. 9 is a graph showing that the needle current (discharge current) is controlled by adjusting the needle electrode voltage (discharge voltage) based on needle current monitoring results according to the second embodiment of the present invention. FIG. 11 is a flow chart showing an example of a procedure of processing when a control unit according to a third embodiment of the present invention executes a spectrum monitoring function; FIG. 9 is a graph showing that the ion intensity of target ions is controlled by adjusting the needle electrode voltage (discharge voltage) based on the spectrum monitoring results according to the third embodiment of the present invention. FIG. 11 is a diagram showing an example of a replacement information screen displaying replacement timing and estimated cost, which can be calculated using the needle current monitoring function or the spectrum monitoring function according to the fourth embodiment of the present invention;

Hereinafter, examples of embodiments for carrying out the present invention will be described with reference to the accompanying drawings. As an example of a mode for carrying out the present invention, an example of a schematic configuration of a dangerous substance detection device, an example of a comprehensive relationship between a needle current monitoring function, a spectrum monitoring function, and a voltage adjustment function will be described. It should be noted that the contents of the device configuration and processing operations described here are examples of the embodiment of the present invention, and modifications by combining or replacing them with known techniques are also included in the scope of the present invention. In this specification and the accompanying drawings, constituent elements having substantially the same function or configuration are denoted by the same reference numerals, and overlapping descriptions are omitted.

<First Embodiment>
[Control system of dangerous goods detection device]
FIG. 1 is a diagram showing a configuration example of a control system of a dangerous substance detection device provided with an ionization section that performs corona discharge according to a first embodiment of the present invention. A dangerous substance detection device 1 shown in FIG. . The dangerous substance detection device 1 shown in FIG. 1 is a schematic representation of its overall configuration, and individual configurations including the analysis unit 7 are not limited to the disclosed example.

The card insertion part 2 is a part for inserting an inspection object such as a smart card (hereinafter referred to as "card C") used when a user passes through a gate (not shown) installed in a building or facility. . In the present invention, fine particles and/or gases adhering to the surface of the card C inserted from the card insertion portion 2 are used as substances to be inspected. In the following, particulates and/or gases are simply referred to as "particles". In this embodiment, these microparticles are analyzed as samples. The authentication unit 3 authenticates the card C placed on or above the reading surface, opens the gate if the authentication succeeds, and closes the gate if the authentication fails.

In the present embodiment, the card C (smart card, etc.) is the object to be inspected, but the object to be inspected may be a card holder, bag, clothes, fingers, or the like.

The air supply unit 4 blows compressed air onto the card C inserted from the card insertion unit 2 to remove fine particles adhering to the card C surface. The separated fine particles are sucked into the suction port 5 . The suction port 5 is a member having a shape surrounding the fine particle passage. The collecting part 6 collects the particles separated from the card C and sucked into the suction port 5 . A cyclone-type concentrating section, for example, is used for the collecting section 6 . The collecting part 6 is a part that separates the collected fine particles according to their weight, concentrates the fine particles with a filter provided in the lower part of the collecting part 6, and increases the detection sensitivity. The collection unit 6 , for example, vaporizes the concentrated microparticles by heating cloth (or paper), and introduces the vaporized microparticles (gas) into the ionization chamber 11 of the analysis unit 7 . An impactor may be used for the collection unit 6 .

The analysis unit 7 includes an ionization unit 10 , a detection unit 13 , a control unit 14 , a determination unit 15 and a mass DB 16 . The ionization section 10 is composed of an ionization chamber 11 and a high voltage section 12 . The analysis unit 7 analyzes the components of the collected fine particles and transmits the analysis results to the output unit 8 .

Here, the configuration of the analysis unit 7 will be described in detail. An ionization chamber 11 of the analysis unit 7 is provided with a needle electrode 11a and a counter electrode 11b. In the ionization chamber 11, corona discharge is generated between the needle electrode 11a and the counter electrode 11b to ionize fine particles present near the needle electrode 11a. The high voltage section 12 applies a DC voltage to both the needle electrode 11a and the counter electrode 11b to generate a high voltage between the needle electrode 11a and the counter electrode 11b, thereby generating corona discharge. By applying a DC voltage different from that of the needle electrode 11a to the counter electrode 11b, ions having a polarity opposite to that of the counter electrode 11b can be drawn into the detection unit 13 through pores formed deeper than the counter electrode 11b. .

The detector 13 detects the ions generated in the ionization chamber 11 using, for example, a mass spectrometry technique, and analyzes the mass (component) of the collected particles from information on the detected ions. The determination unit 15 compares the results (for example, mass spectrum) analyzed by the detection unit 13 with a library in which the molecular weights of various substances in the mass database (mass DB 16) are registered, and the detection target substance (in this embodiment, to determine the presence or absence of mass spectra derived from hazardous substances).

The control unit 14 is notified of the determination result of the determination unit 15 regarding the presence or absence of a dangerous substance. The control unit 14 transmits the determination result of the determination unit 15 to the output unit 8 , and the determination result is output to the output unit 8 . For example, the output unit 8 is the display device 24 shown in FIG. 2, which will be described later, or a speaker (not shown) that emits a warning sound or voice.

The control section 14 controls the operation of the analysis section 7 . Alternatively, the control unit 14 may control the entire dangerous object detection device 1 in an integrated manner. As will be described later, in the present invention, the controller 14 adjusts the discharge voltage applied to the needle electrode 11a according to the result of a needle current monitoring function (see FIG. 5) or a spectrum monitoring function (see FIG. 7), which will be described later. Use the adjust function. By controlling the voltage applied to the needle electrode 11a by the high voltage unit 12 under the control of the control unit 14, it is possible to output a discharge voltage suitable for the degree of deterioration of the needle electrode 11a that generates corona discharge. .

The control unit 14 adjusts the voltage applied from the high voltage unit 12 to the needle electrode 11a and the counter electrode 11b based on the value of the current flowing through the needle electrode 11a (hereinafter abbreviated as "needle current").

The measurement unit 17 is configured to measure a current (needle current) flowing through the needle electrode 11a when a voltage is applied to the needle electrode 11a, and transmit the measured current value to the control unit 14. For example, the measurement unit 17 is an ammeter. The measurement unit 17 may also be configured to measure a current that flows when a voltage is applied to the counter electrode 11 b (hereinafter referred to as “counter current”) and transmit the measured current value to the control unit 14 . In this embodiment, the measurement unit 17 is configured to measure the needle current, but the measurement unit 17 may be configured to measure the voltage applied to the needle electrode 11a. Values can be converted from current and voltage to each other.

In this embodiment, the ionization method has been described using corona discharge as an example, but the ionization method is not limited to corona discharge, and glow discharge, barrier discharge, and the like can also be applied.

In addition, in this embodiment, the analysis unit 7 is used to detect dangerous substances in the dangerous substance detection device 1, but the analysis unit 7 can of course be used to detect target substances other than dangerous substances. be. That is, a configuration in which the analysis unit 7 is mounted on a device other than the dangerous substance detection device 1 is also conceivable.

[Hardware configuration of analysis unit]
Next, the hardware configuration of the control system provided in the analysis unit 7 of the dangerous substance detection device 1 will be described with reference to FIG.

FIG. 2 is a diagram showing a configuration example of hardware of a control system provided in the analysis unit 7 of the dangerous substance detection device 1. As shown in FIG. The illustrated computer 20 is hardware used as a so-called computer. A personal computer, a microcomputer, or the like can be used as the computer 20 . The computer 20 includes a CPU (Central Processing Unit) 21 , a ROM (Read Only Memory) 22 , a RAM (Random Access Memory) 23 , a display device 24 , an input device 25 , a nonvolatile storage 26 and an input/output interface 27 . Each unit in the computer 20 is connected via a system bus so as to be able to transmit and receive data to and from each other.

The CPU 21 reads from the ROM 22 a software program that implements each function of the analysis unit 7 according to this embodiment, develops the program in the RAM 23, and executes it. The control unit 14 and the determination unit 15 are implemented by the CPU 21 executing the program.

The ROM 22 is used as an example of a nonvolatile memory (recording medium). The ROM 22 stores an OS (Operating System), various parameters, a program for causing the analysis unit 7 to function, and the like. The RAM 23 is temporarily written with variables, parameters, and the like generated in the process of arithmetic processing of the CPU 21 . Another processor such as an MPU (Micro Processing Unit) may be used as an arithmetic processing device instead of the CPU 21 .

The display device 24 is a monitor such as a liquid crystal display, and displays a GUI screen, results of processing performed by the CPU 21, and the like. The input device 25 generates an input signal according to the user's operation and outputs it to the CPU 21 . For example, a mouse, a keyboard, or the like is used as the input device 25, and the user can operate the input device 25 to input information and instructions. The display device 24 and the input device 25 may be integrated as a touch panel.

The non-volatile storage 26 is an example of a recording medium, and can store data used by programs, data obtained by executing programs, and the like. For example, non-volatile storage 26 stores information of mass database 16 . Also, an OS (Operating System) and a program executed by the CPU 21 may be recorded in the nonvolatile storage 26 . As the nonvolatile storage 26, a HDD (Hard Disk Drive), an SSD (Solid State Drive), a disk device using magnetism or light, a semiconductor memory card, or the like is used.

The input/output interface 27 transmits and receives various data and control signals to and from a control system (not shown) included in the dangerous object detection device 1 (for example, a control system that executes processing according to the authentication result of the authentication unit 3). is configured to allow

[Voltage adjustment mode]
FIG. 3 is a flow chart showing an outline of processing by the control unit 14 in the voltage adjustment mode according to the first embodiment of the present invention. The CPU 21 executes the program recorded in the ROM 22 to perform the processing of this flowchart. When an abnormality is detected in the needle current monitoring function (see FIG. 5) or the spectrum monitoring function (see FIG. 7), which will be described later, the mode is changed to the voltage adjustment mode.

When the voltage adjustment mode is started (S1), the control unit 14 determines whether or not there is a discharge abnormality notification from the needle current monitoring function (see FIG. 5) or the spectrum monitoring function (see FIG. 7) (S2). If there is no notice of discharge abnormality (NO in S2), the process proceeds to step S4. On the other hand, when there is a notice of discharge abnormality (YES in S2), the control unit 14 executes the voltage adjustment function (see FIG. 4) (S3). Next, after executing the voltage adjustment function, the control unit 14 determines and updates the discharge voltage set value based on the result (S4), and ends the process in the voltage adjustment mode (S5). The determined discharge voltage setting value is stored in the RAM 23 or the nonvolatile storage 26 . After returning to the normal mode for performing analysis, the control unit 14 outputs a discharge voltage from the high voltage unit 12 based on the updated discharge voltage set value to stabilize corona discharge, that is, ionization.

However, when the dangerous substance detection device 1 is in a standby mode (not shown) by satisfying a preset condition, the needle current monitoring function (see FIG. 5) or the spectrum monitoring function (see FIG. 7) detects an abnormality as a result of monitoring. has occurred, the configuration may be such that the mode is shifted to the voltage adjustment mode and the voltage adjustment is performed. In the standby mode, for example, it is assumed that some functions, such as a card acceptance function and an authentication function when a user enters and leaves a room, are restricted. However, these functional restrictions are not eliminated in the voltage regulation mode.

[Voltage adjustment function]
Next, the details of the voltage adjustment function of the analysis unit 7 will be described with reference to FIG.
FIG. 4 is a flowchart showing an example of the procedure of processing when the control unit 14 according to the first embodiment of the present invention executes the voltage adjustment function. The CPU 21 executes the program recorded in the ROM 22 to perform the processing of this flowchart.

The voltage regulation function shown in FIG. 4 is activated during the voltage regulation mode shown in FIG. Based on the result of the needle current monitoring function (see FIG. 5) or the spectrum monitoring function (see FIG. 7), the control unit 14 determines whether to execute the voltage adjustment function, generates a voltage adjustment command, and uses the voltage adjustment command as a trigger. Execution of the voltage adjustment function is started (S11).

Next, the control unit 14 estimates the resistance value of the needle electrode 11a from the result of the needle current monitoring function, and uses the voltage immediately before the transition to the voltage adjustment mode to determine the current generated in the needle electrode 11a when the voltage is applied. (lower limit and upper limit) is determined (S12). At the first time, the voltage of the initial set value is applied to the needle electrode 11a. For the second and subsequent times, for example, the value determined last time is used as the applied voltage. For example, the resistance value of the needle electrode 11a is calculated from the voltage applied from the high voltage unit 12 to the needle electrode 11a and the current value (needle electrode current value) flowing through the needle electrode 11a measured by the measuring unit 17 at this time. can.

Next, the control section 14 applies a specified voltage to the needle electrode 11a by the high voltage section 12 (S13). The control unit 14 applies a voltage to the needle electrode 11a for several seconds, and the measurement unit 17 measures the current flowing through the needle electrode 11a at predetermined time intervals (for example, several ms) to calculate an average value (needle electrode current average value). .

Next, the control unit 14 determines whether or not the needle electrode current average value calculated in step S13 is within the normal range (above the lower limit and below the upper limit) determined in step S12 (S14). If the needle electrode current average value is within the normal range (YES in S14), the controller 14 determines the voltage applied in step S13 as the voltage (discharge voltage) to be applied to the needle electrode 11a during corona discharge (S19). , the voltage regulation ends (S20). After the process of step S20, the process proceeds to step S4 of FIG.

On the other hand, when the electrode current average value is not within the normal range (NO in S14), the controller 14 determines whether the needle electrode current average value is smaller than the lower limit (S15). Then, if the needle electrode current average value is smaller than the lower limit value (YES in S15), the controller 14 increases the applied voltage by a predetermined step value and updates it (S16) so that the needle electrode current average value is equal to or higher than the lower limit value. (NO in S15), the applied voltage is decreased by a predetermined step value and updated (S17). Then, the control unit 14 recalculates (updates) the average value of the needle electrode current.

Next, the control unit 14 determines again whether or not the recalculated needle electrode current average value is within the normal range (above the lower limit and below the upper limit) determined in step S12 (S18). If the recalculated needle electrode current average value is within the normal range (YES in S18), the controller 14 proceeds to the process of step S19.

On the other hand, if the recalculated needle electrode current average value is not within the normal range (NO in S18), the control unit 14 returns to step S12 and changes the applied voltage to adjust the current range (upper limit and lower limit). Decide again. Then, the processes of steps S13 and S14 are executed, and further the processes of steps S15 to S18 are appropriately executed as necessary.

In this embodiment, in order to prevent an infinite loop, if the needle electrode current average value does not reach the normal range even after performing the voltage adjustment several times (for example, four times) in steps S16 and S17 (NO in S18), , the control unit 14 forcibly transitions to the end of voltage adjustment (S20). Then, the control section 14 outputs a needle electrode replacement message to the output section 8 . Here, the narrower the width of the normal range of the needle electrode current average value, the more optimal the discharge voltage can be set. It is desirable to

As described above, the mechanism for collecting the sample from the test object (for example, the air supply unit 4, the intake port 20, the collection unit 6) and the discharge between the electrodes (needle electrode 11a, counter electrode 11b) are used to collect the sample. An ionization part that ionizes, a detection part that detects and analyzes the ionized sample, and a detection part that detects the current flowing through the electrode or the voltage applied to the electrode when starting the discharge from the stopped state of the discharge, or the start of the discharge. and a control unit that monitors the discharge state based on the mass spectrum obtained in , and adjusts the discharge voltage required to generate discharge by the electrodes based on the monitoring result of the discharge state.

In addition, in the dangerous substance detection device 1 (analysis unit 7) according to the present embodiment, the control unit monitors the discharge state between the electrodes, and adjusts the discharge voltage when it is determined that the ionization has become unstable. is configured to do

The dangerous substance detection device 1 (analysis unit 7) according to the first embodiment configured as described above monitors the electrode (needle electrode 11a or counter electrode 11b) used for ionization in the analysis unit 7 to detect the discharge voltage. is adjusted, stable discharge can be realized even when the electrodes are deteriorated. As a result, for example, even when an oxide film is formed on the electrode, it is possible to continue discharging and extend the usable time of the consumable electrode.

<Second embodiment>
As a second embodiment, details of the needle current monitoring function of the analysis unit 7 will be described with reference to FIG. The needle current monitoring function and the spectrum monitoring function, which will be described later, monitor the discharge state with the needle current (or needle voltage) and the mass spectrum when the discharge by the ionization unit 10 is started from the stopped state.

FIG. 5 is a flow chart showing an example of the procedure of processing when the control unit 14 according to the second embodiment of the present invention executes the needle current monitoring function. The CPU 21 executes the program recorded in the ROM 22 to perform the processing of this flowchart.

First, when the dangerous substance detection device 1 is in the analysis-enabled state, the controller 14 issues a needle current monitoring command to start execution of the needle current monitoring function (S31). Next, the controller 14 causes the high voltage unit 12 to apply a predetermined voltage to the needle electrode 11a, the measurement unit 17 obtains the needle current at predetermined intervals, and the number of times of acquisition recorded in the RAM 23 (see FIG. 2). is incremented (S32). That is, the value of the acquisition count is incremented by one. The voltage value applied to the needle electrode 11a is determined in advance.

Next, the control unit 14 determines whether or not the obtained needle current exceeds the current maximum value (S33). If the obtained needle current exceeds the current maximum value (YES in S33), the needle current The value is updated and stored in RAM 23 (S34). If the acquired needle current is equal to or less than the current maximum value (NO in S33), the process proceeds to determination processing in step S35.

Next, after the process of step S34 or in the case of a NO determination in step S33, the control unit 14 repeats acquisition of the needle current up to the set number of times. That is, the control unit 14 determines whether or not the number of acquisitions of the needle current has reached the set number (S35). move on. On the other hand, if the number of times of acquisition has not reached the set number of times (NO in S35), the processing of steps S32 to S35 is repeated.

Next, if the determination in step S33 is YES, the control unit 14 determines whether or not the needle current maximum value is outside the normal range. That is, the control unit 14 determines whether the maximum needle current value is smaller than a preset lower limit current value or larger than a preset upper limit current value (S36). Here, if the needle current maximum value is not outside the normal range, that is, if the needle current maximum value is within the normal range (NO in S36), the control unit 14 resets the needle current acquisition count (S38 ), and transitions to end of needle current monitoring (S39).

On the other hand, if the needle current maximum value is outside the normal range (YES in S36), the control section 14 notifies the output section 8 that the needle electrode 11a is abnormal (warning). Further, the control unit 14 shifts to the voltage adjustment mode and executes the voltage adjustment function (see FIG. 4) (S37). A standby mode may be used instead of the voltage adjustment mode. The normal range (upper limit, lower limit) of the needle current maximum value depends on the needle electrode 11a used. After the process of step S37, the control unit 14 resets the needle current acquisition count (S38), and transitions to end of needle current monitoring (S39).

With such a needle current monitoring function, deterioration of the needle electrode 11a, that is, abnormality of the needle electrode 11a can be detected, and a voltage adjustment function can be performed so that corona discharge is appropriately performed. Further, since the needle electrode 11a can be replaced immediately after confirming the abnormality notification to the output unit 8 (for example, when there is no card inspection request), the availability of the dangerous substance detection device 1 is improved. For example, it is possible to avoid a situation in which the dangerous substance detection device 1 cannot be used due to an abnormality in the needle electrode 11a when there is a card inspection request and the user wishes to use the dangerous substance detection device 1.

Furthermore, since the needle electrode 11a can be immediately replaced upon receipt of an abnormality notification (for example, when there is no card inspection request), it is possible to avoid continuing use of the dangerous substance detector 1 in a state where ionization is unstable. and the reliability of the dangerous object detection device 1 is improved. Even when the counter electrode 11b is monitored, the same effect as the needle electrode 11a can be obtained.

Here, an example in which the needle electrode voltage (discharge voltage) is adjusted based on the needle current monitoring result and the needle current (discharge current) is controlled will be described with reference to FIG. By adjusting the needle electrode voltage, the voltage between the needle electrode 11a and the counter electrode 11b, that is, the discharge voltage can be adjusted.

FIG. 6 is a graph showing that the needle electrode voltage (discharge voltage) is adjusted and the needle current (discharge current) is controlled based on the needle current monitoring result according to the second embodiment of the present invention. In FIG. 6, the horizontal axis indicates the elapsed time [sec] from the start of the discharge, the left vertical axis indicates the needle current [μA], and the right vertical axis indicates the voltage applied to the needle electrode 11a (needle electrode voltage). represents [V].

A thin solid line (region) in the graph indicates the needle current, a thick solid line indicates the maximum value of the needle current, and a broken line indicates the voltage applied to the needle electrode 11a. FIG. 6 shows an example in which a negative voltage is applied as the needle electrode voltage. When a negative voltage is applied to the needle electrode 11a and a positive voltage is applied to the counter electrode 11b, the needle electrode 11a functions as an electrode for generating negative ions.

As shown in FIG. 6, the maximum value of the needle current is controlled by adjusting the voltage (needle electrode voltage) applied to the needle electrode 11a by the voltage adjustment function according to changes in the maximum value of the needle current. I understand. For example, in FIG. 6, a needle electrode voltage of −3400 V was applied from time 0 to 400 sec, but the maximum value of the needle current decreased from 30 μA to 15 μA. As described above, an electrode for discharging has an insulating oxide film formed on its surface as time elapses, resulting in a decrease in discharge capability.

Therefore, by increasing the needle electrode voltage to −3700 V after 400 seconds, the maximum value of the needle current is increased to about 38 μA. Similarly, by increasing the magnitude of the needle electrode voltage at times of 1250 sec and 2000 sec, respectively, the maximum value of the needle current increases. Conversely, since the needle current becomes too large (approximately 51 μA) from 2900 sec, the needle electrode voltage is lowered from -3900 V to -3600 V at 3000 sec, thereby lowering the needle current to -3460 V. there is

In addition, even when the discharge voltage is switched between positive and negative, the control unit 14 measures the values of the positive current and the negative current flowing through the needle electrode 11a and outputs the optimum value of the needle current (discharge current). By switching the discharge voltage between positive and negative, it is possible to measure both a substance that tends to be negatively ionized and a substance that is likely to be positively ionized. Further, when the discharge current becomes an abnormal value, the control unit 14 can control the current value of the needle electrode 11a to correct the discharge current so that it falls within the normal range.

As described above, in the dangerous substance detection device 1 (analysis unit 7) according to the second embodiment, the ionization unit includes a needle electrode that is arranged in the ionization chamber that generates ions and generates discharge, and a counter electrode. Prepare. When the maximum value of the current flowing through the needle electrode deviates from a preset normal range, the control unit judges that the ionization has become unstable, outputs an error, and adjusts the discharge voltage. is configured to

<Third Embodiment>
As a third embodiment, the details of the spectrum monitoring function of the analysis unit 7 will be described with reference to FIG.

FIG. 7 is a flow chart showing an example of the procedure of processing when the control unit 14 according to the third embodiment of the present invention executes the spectrum monitoring function. The CPU 21 executes the program recorded in the ROM 22 to perform the processing of this flowchart.

First, when the dangerous substance detection device 1 is in the analysis enabled state, the control unit 14 issues a spectrum monitoring command to start execution of the spectrum monitoring function (S41). Next, the control unit 14 causes the ionization unit 10 to perform corona discharge while the card C is not accepted, and the mass (specifically, the mass-to-charge ratio ( m/z values)) are added together. The voltage value applied to the needle electrode 11a is determined in advance. Then, the control unit 14 calculates the time average value (hereinafter referred to as "count value average value") of the sum of the ion intensities of the masses within the monitoring target range (count value), and puts it into an argument (S42 ). That is, the control unit 14 substitutes the average count value for “C_AVG” in the determination formula “C_AVG≦threshold?” used in the next step S43.

Next, the control unit 14 determines whether or not the average count value C_AVG is equal to or less than a preset threshold (S43). Here, if the average count value C_AVG is equal to or less than the threshold value (YES in S43), the control unit 14 determines the number of times the average count value C_AVG is equal to or less than the threshold value (number of times equal to or less than the threshold value) and the count value The number of times that the average value C_AVG is continuously determined to be equal to or less than the threshold value (number of consecutive times equal to or less than the threshold value) is incremented (S44). That is, each value of the number of times below the threshold value and the number of consecutive times below the threshold value is increased by one. If the average count value is less than or equal to the threshold, it is assumed that the amount of ions generated is small.

On the other hand, when the count value average value C_AVG is larger than the threshold value (NO in S43), the control unit 14 resets the number of consecutive values equal to or less than the threshold value (S45).

After the process of step S44 or S45, the control unit 14 determines whether or not the number of times the average count value C_AVG has become equal to or less than the threshold (the number of times equal to or less than the threshold) is equal to or greater than the set number of times (S46). If the number of times below the threshold is greater than or equal to the set number of times (YES in S46), the control unit 14 determines that the ionization in the ionization unit 10 is unstable (S47), and proceeds to step S50.

On the other hand, when the number of times below the threshold is less than the set number of times (NO in S46), the control unit 14 determines whether the number of times below the threshold in succession is equal to or greater than the set number of consecutive times (S48). Here, the control unit 14 also determines that the ionization in the ionization unit 10 is unstable when the number of consecutive times below the threshold is equal to or more than the set consecutive number of times (YES in S48) (S49). If the number of consecutive times equal to or less than the threshold is less than the set consecutive number of times (NO in S48), the control unit 14 proceeds to the determination process of step S51.

After the process of step S47 or S49, the control unit 14 increments the number of times of monitoring instability, which indicates the number of times the ionization is determined to be unstable (S50). That is, the number of instability monitoring times is increased by one.

Next, the control unit 14 determines whether or not the number of instability monitoring times is equal to or greater than the set number of times (S51), and if the number of times of instability monitoring is less than the set number of times (NO in S51), spectrum monitoring ends (S53). transition to

On the other hand, if the number of times of instability monitoring is equal to or greater than the set number of times (YES in S51), the control section 14 notifies the output section 8 that the needle electrode 11a is abnormal (warning). Further, the control unit 14 shifts to the voltage adjustment mode and executes the voltage adjustment function (see FIG. 4) (S52). A standby mode may be used instead of the voltage adjustment mode. After the process of step S52, the control unit 14 transitions to end of spectrum monitoring (S53).

The lower the threshold number of times (set number of times, set consecutive number of times) used for abnormality determination, the more accurate the discharge voltage can be output from the high-voltage section 12, leading to suppression of deterioration of the needle electrode 11a. However, the lower the number of times threshold used for abnormality determination, the more easily the dangerous substance detection device 1 transitions to the voltage adjustment mode (or the standby mode), and thus the availability decreases. Therefore, it is necessary to appropriately set the number of times threshold used for the abnormality determination in consideration of the operational status.

Such a spectrum monitoring function provides the same effect as the needle current monitoring function in the second embodiment. Furthermore, the spectrum monitoring function does not require the measurement unit 17 for measuring the current of the electrodes, and the configuration of the analysis unit 7 can be simplified. Further, even when the counter electrode 11b is used as a monitoring target, the same effects as in the case of the needle electrode 11a can be obtained.

Here, an example in which the ion intensity (discharge) is controlled by adjusting the needle electrode voltage (discharge voltage) based on the spectrum monitoring result will be described with reference to FIG.

FIG. 8 is a graph showing that the ion intensity of target ions is controlled by adjusting the needle electrode voltage (discharge voltage) based on the spectrum monitoring results according to the third embodiment of the present invention. In this embodiment, examples of adjusting the needle electrode voltage for two ions having different m/z values are shown in FIGS. 8A and 8B. FIG. 8A is a graph for ions with an m/z value of "91", and FIG. 8B is a graph for ions with an m/z value of "288".

8A and 8B, the horizontal axis indicates time [sec], and the left vertical axis indicates normalized ion intensity [a. u. ], and the vertical axis on the right side represents the voltage applied to the needle electrode 11a (needle electrode voltage) [V]. In the graph, a thin solid line (region) indicates ionic strength, a thick solid line indicates average ionic strength, and a dashed line indicates needle electrode voltage. FIG. 8A shows an example in which a positive voltage is applied as the needle electrode voltage, and FIG. 8B shows an example in which a negative voltage is applied as the needle electrode voltage.

As shown in FIGS. 8A and 8B, the voltage (needle electrode voltage) applied to the needle electrode 11a is adjusted by the voltage adjustment function in accordance with the change in the ion intensity (the average value of the ion intensity). value) is controlled.

For example, in FIG. 8A, a needle electrode voltage of 3700 V was applied from time 0 to 1250 sec, but the average ion intensity decreased from 41000 to 28000 after time 700 sec. Therefore, by raising the needle electrode voltage to 4100 V at the point of 1250 sec, the average value of the ion intensity rises to the same level.

In FIG. 8B, the needle electrode voltage is increased stepwise three times from time 0 sec to time 3000 sec. The needle electrode voltage was initially -3400 V, changed to -3700 at time 400 sec, then -3800 V at time 1250 sec, and then changed to -3900 at time 2000 sec. As a result, it is possible to control the average value of the ion intensity to be kept almost constant between the time 0 and 3000 sec.

As described above, in the dangerous substance detection device 1 (the analysis unit 7) according to the third embodiment, when monitoring the discharge state by the mass spectrum, the control unit sums the ion intensities of the masses within the monitoring target range. Based on the fact that the count value is determined to be below the threshold, it is determined that the ionization has become unstable, and if the number of times the ionization has become unstable is greater than or equal to the threshold, an error is output. and is configured to adjust the discharge voltage.

Further, in the dangerous substance detection device 1 (the analysis unit 7) according to the present embodiment, the control unit sets the threshold value, which is the number of times the count value obtained by adding the ion intensities of the masses within the monitoring target range is determined to be equal to or less than the threshold value. When the number of times below is equal to or greater than the set number of times, or when the number of times the count value is continuously determined to be equal to or less than the threshold is equal to or greater than the set number of consecutive times, ionization is in an unstable state. It is configured to determine that it has become

<Fourth Embodiment>
Next, as a fourth embodiment, a replacement information screen displaying the replacement timing and estimated cost that can be calculated using the needle current monitoring function or the spectrum monitoring function will be described with reference to FIG.

FIG. 9 is a diagram showing an example of a replacement information screen displaying replacement timing and expected cost, which can be calculated using the needle current monitoring function or the spectrum monitoring function according to the fourth embodiment of the present invention. A replacement information screen 90 shown in FIG. 9 has an area for displaying a next recommended replacement date 91, an area for displaying an average replacement interval 92, and an area for displaying an expected cost 93 for the next year. Further, the replacement information screen 90 displays a needle electrode selection button 94 and a counter electrode selection button 95 .

The recommended next replacement date 91 is calculated from the past replacement history of each electrode (needle electrode 11a, counter electrode 11b) and the execution frequency of the voltage adjustment function using the needle current monitoring function or the spectrum monitoring function. It is the next exchange time (for example, year:month:day). As described above, by setting the counter electrode 11b to be monitored, the needle current monitoring function can also be used to monitor deterioration of the counter electrode 11b.

The average replacement interval 92 is an average value of replacement intervals (for example, replacement is performed Y times every Y months) calculated from the past replacement history of each electrode.
The next year's expected cost 93 is the cost of next year's replacement maintenance expected from the next year's electrode replacement plan based on the current year's (and previous year's) replacement history of each electrode and the actual replacement cost.

The needle electrode selection button 94 is a button (icon) for displaying information about the needle electrode 11a, such as the replacement history, future replacement timing, expected cost, and the like. When the user presses the needle electrode selection button 94 with the input device 25, the replacement information of the needle electrode 11a is displayed on the replacement information screen 90. FIG.
The counter electrode selection button 95 is a button (icon) for displaying information about the counter electrode 11b, such as the replacement history, future replacement timing, estimated cost, and the like. When the user presses the counter electrode selection button 95 with the input device 25, the exchange information of the counter electrode 11b is displayed on the exchange information screen 90. FIG.

By referring to this replacement information screen 90, the user can know the proper replacement time for the needle electrode 11a (and the counter electrode 11b) and can make efforts for preventive maintenance. Knowing the replacement time in advance makes it possible to smoothly prepare a new electrode, arrange maintenance personnel, and replace the electrode, thereby improving the availability of the dangerous substance detection device 1 .

As described above, the dangerous substance detection device 1 (analysis unit 7) according to the fourth embodiment has an area displaying buttons for selecting electrodes (needle electrode 11a, counter electrode 11b) and A selection screen interface (replacement information screen 90) having areas displaying the replacement status (average replacement interval 92) and the next replacement time (recommended next replacement date 91) of the corresponding electrode is provided.

<Modification>
Furthermore, the present invention is not limited to the first to fourth embodiments described above, and various other applications and modifications can be made without departing from the gist of the present invention described in the claims. Of course. For example, each of the above-described embodiments is a detailed and specific description of the configuration of the dangerous substance detection device (analyzer) in order to explain the present invention in an easy-to-understand manner, and does not necessarily include all the components described. Not limited. Also, it is possible to replace part of the configuration of one embodiment with the constituent elements of another embodiment. It is also possible to add components of other embodiments to the configuration of one embodiment. Moreover, it is also possible to add, replace, or delete other components for a part of the configuration of each embodiment.

Further, each of the configurations, functions, processing units, etc. described above may be realized by hardware, for example, by designing a part or all of them using an integrated circuit. As hardware, a broadly defined processor device such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit) may be used.

In addition, in the flowcharts describing the time-series processing shown in FIGS. 4, 5, and 7, multiple processes may be executed in parallel or the processing order may be changed within a range that does not affect the processing results. You can

In addition, in the dangerous substance detection device 1 shown in FIG. 1, control lines and information lines are considered to be necessary for explanation, and not all control lines and information lines are necessarily shown on the product. . In practice, it may be considered that almost all components are interconnected.

DESCRIPTION OF SYMBOLS 1... Hazardous substance detector, 2... Card insertion part, 3... Authentication part, 4... Scavenging part, 5... Suction port, 6... Collection part, 7... Analysis part, 8... Output part, 10... Ionization part, 11 Ionization chamber 11a Needle electrode 11b Counter electrode 12 High voltage unit 13 Detection unit (mass analysis unit) 14 Control unit 15 Judgment unit 16 Mass DB 17 Measurement unit 20... calculator, 90... replacement information screen, 91... recommended next replacement date, 92... average replacement interval, 93... estimated cost for next year, 94... needle electrode selection button, 95... counter electrode selection button, C... card (inspection object )

Claims (7)

an ionization unit that ionizes a sample using discharge between electrodes;
a detection unit that detects and analyzes the ionized sample;
When the discharge is started from a state in which the discharge is stopped, the discharge state is monitored by the current flowing in the electrode or the voltage applied to the electrode, or the mass spectrum obtained by the detection unit at the start of the discharge, and the discharge is performed. a controller that adjusts the discharge voltage required to generate the discharge by the electrodes based on the monitoring of conditions. The analyzer according to claim 1, wherein the controller monitors the discharge state, and adjusts the discharge voltage when determining that the ionization has become unstable. The ionization unit includes a needle electrode that is arranged in an ionization chamber that generates ions and generates a discharge, and a counter electrode,
When the maximum value of the current flowing through the needle electrode deviates from a preset normal range, the control unit determines that the ionization is in an unstable state, outputs an abnormality, and adjusts the discharge voltage. The spectrometer of claim 2. When the discharge state is monitored by the mass spectrum, the control unit determines that the ionization is unstable based on the determination that the count value obtained by adding the ion intensities of the masses within the monitoring target range is equal to or less than a threshold. 3. The analyzer according to claim 2, wherein it determines that a state has been established, and outputs an abnormality and adjusts the discharge voltage when the number of times the ionization becomes unstable is equal to or greater than a threshold value. When the number of times the count value obtained by adding the ion intensities of the masses within the monitoring target range is determined to be equal to or less than the threshold is equal to or greater than a set number of times, or the count value is equal to or less than the threshold 5. The spectrometer according to claim 4, wherein it is determined that the ionization is in an unstable state when the number of times of consecutive determinations equal to or less than the threshold is equal to or greater than a set number of consecutive times. a mechanism for collecting a sample from a test subject;
an ionization unit that ionizes the sample using discharge between electrodes;
a detection unit that detects and analyzes the ionized sample;
When the discharge is started from a state in which the discharge is stopped, the discharge state is monitored by the current flowing in the electrode or the voltage applied to the electrode, or the mass spectrum obtained by the detection unit at the start of the discharge, and the discharge is performed. a control unit that adjusts a discharge voltage required for generating the discharge by the electrode based on a state monitoring result. A selection screen interface used in a dangerous substance detection device that detects a dangerous substance by detecting an ionized sample using discharge between electrodes,
an area displaying buttons for selecting the electrode;
A selection screen interface having an area for displaying the replacement status and the next replacement time of the electrode corresponding to the selected button.

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