JP4484674B2 - Glow discharge emission analyzer - Google Patents

Description

The present invention is to produce a high-frequency power so that the average voltage of the RF voltage applied to the sample is constant, about glow discharge emission spectroscopy 析装 location you allow at stable and high-accuracy sample analysis.

  Conventionally, light emission is caused by glow discharge by applying a high-frequency voltage to a sample, the intensity is measured by spectroscopically analyzing the emitted light for each wavelength, and the measured value is taken into an analytical instrument such as a computer. There is a glow discharge emission spectrometer that analyzes components (elements contained in a sample).

  In a conventional glow discharge emission spectrometer, a sample to be analyzed is placed opposite to an electrode of a glow discharge tube, and an inert gas (for example, argon gas) is supplied to the sample surface. Generator generates a glow discharge by applying a high frequency voltage (alternating voltage) of about 13 MHz to the sample. By the generation of glow discharge, ions of inert gas (for example, argon ions) are generated, and the generated ions are accelerated by a high electric field and collide with the sample surface, so that substances (elements) contained in the sample are exposed ( Called Sputtering). The element expressed by sputtering emits light at a specific wavelength, and the element contained in the sample is analyzed by measuring the emitted intensity with a spectroscope. (See Patent Document 1).

During glow discharge, the impedance value of the sample itself changes with sputtering. When the impedance value of the sample changes, stable power supply to the sample is hindered, so the power supply unit of the glow discharge emission spectrometer is a matching box that adjusts the power supply in response to changes in the impedance value of the sample in addition to the generator Equipment. Note that the power supply unit (generator) supplies a constant value of high-frequency power to the sample during sample analysis.
JP 2001-4548 A

  In the conventional glow discharge emission spectrometer, there is a state in which sputtering generated between the electrode of the glow discharge tube and the sample becomes unstable during power feeding to the sample. That is, there is a case where good power supply to the sample is hindered due to a phenomenon that the surface of the sample is worn by receiving a load due to sputtering and the distance between the electrode and the sample surface changes. In such a case, the progress of the current flowing from the power supply unit of the glow discharge emission spectrometer to the sample is hindered, and a situation occurs in which the output voltage of the power supply unit increases due to this state.

  As a result, as shown in FIG. 15, the potential difference (V1 ≠ V2 ≠ V3: average potential difference) between the electrode of the glow discharge tube and the sample is displaced according to the time zone during power feeding. When the potential difference is displaced, sputtering becomes unstable, and the emission intensity changes accordingly. Therefore, there arises a problem that the emission intensity cannot be measured stably and with high accuracy.

The present invention has been made in view of such a problem, and performs control to change the high-frequency power value so that the average voltage value of the AC voltage applied to the sample is constant in order to stabilize the sputtering. and to provide a glow discharge optical emission spectrometer.
It is another object of the present invention to provide a glow discharge optical emission analyzer capable of stably obtaining highly accurate measurement results by reducing the influence of sample wear due to sputtering.

In order to solve the above problems, a glow discharge optical emission spectrometer according to the present invention, the spectrometer the intensity of light emission with an AC voltage of the AC power supply unit is generated glow discharge was generated by applying to the analyte material In the glow discharge optical emission analyzer for measuring in step (1), means for storing a reference voltage value, intermittent application means for intermittently applying an AC voltage to the material to be analyzed at predetermined intervals, and applying to the material to be analyzed A detecting means for detecting an average voltage value related to the AC voltage; a comparing means for comparing the average voltage value detected by the detecting means and a reference voltage value; a judging means for judging a comparison result of the comparing means; Power control means for performing control to change the power value of the AC power generated by the power supply unit according to the determination result of the determination means so that the average voltage value related to the AC voltage applied to the material is constant. With features That.

The glow discharge emission spectrometer according to the present invention is characterized by comprising measurement value acquisition means for acquiring values measured by the spectrometer in synchronization with intermittent application performed by the intermittent application means.

In the present invention, since the power value to be fed is not constant as in the prior art, the power value is changed during the measurement to keep the average voltage value constant. ) And the electrode are constant, and the occurrence of sputtering is uniformly stabilized. As a result, a change in the intensity of light emission accompanying sputtering is suppressed, and a stable measurement result can be obtained.

In the present invention, the power value is changed according to the determination result of comparing the average voltage value related to the AC voltage actually applied to the analyte and the reference voltage value, so that the level matches the actual measurement situation. As a result, the voltage value becomes constant, and an appropriate glow discharge generation condition is ensured to generate stable sputtering, thereby realizing high-accuracy measurement. As the reference voltage value, a value specified in consideration of characteristics of the material to be analyzed, measurement environment, past experience, and the like is appropriately used.

In the present invention, since the AC voltage is intermittently applied to the material to be analyzed by the intermittent application means, sputtering also occurs intermittently, compared to the case where the AC voltage is continuously applied. The degree to which the analyte is worn can be reduced. Therefore, even if a higher voltage value is applied to the measurement than in the past, the influence of the wear of the analyte can be suppressed, so that the emission intensity is increased by the application of the higher voltage value, and the measurement accuracy can be improved.

In the present invention, when performing intermittent application of AC voltage, because the measurement value is acquired from the spectrometer in synchronization with the intermittent application, it is not possible to acquire measurement values including various noise components that occur during non-application, The noise component can be eliminated from the measurement value to be analyzed, and analysis with higher accuracy can be performed.

In the present invention, the average voltage value is made constant by changing the power value during the measurement, so that the potential difference between the sample and the electrode can be made constant, and the stable measurement result by suppressing the fluctuation of sputtering. Can be obtained.
In the present invention, since the power value is changed based on the comparison of the average voltage value and the reference voltage value related to the AC voltage applied to the sample, the value between the sample and the electrode is set to a value that matches the actual measurement. The potential difference can be made constant, sputtering can be stabilized, and highly accurate measurement can be realized.

In the present invention, since the AC voltage is intermittently applied to the material to be analyzed, the degree of wear of the sample can be reduced to enable measurement with a high voltage value applied, and the measurement accuracy can be further improved.
In the present invention, since the measurement value is acquired from the spectrometer in synchronization with intermittent application, various noise components generated during non-application can be eliminated and highly accurate analysis can be performed.

  FIG. 1 shows the overall configuration of a glow discharge emission spectrometer 1 according to an embodiment of the present invention. The glow discharge emission analysis apparatus 1 includes a glow discharge tube 2 that sets a sample S (analyte) and generates glow discharge, a power supply unit 3 that applies a high-frequency voltage to the sample S set in the glow discharge tube 2, and measurement. A gas supply unit 6 for supplying the gas necessary for the glow discharge tube 2, a spectrometer 7 for measuring the light L generated from the glow discharge tube 2 and measuring the intensity of each light, and obtaining measurement values for the sample components An analysis control unit 8 that performs analysis and the like is provided. The power supply unit 3 includes a generator (power generation device) 4 and a matching box 5 that are connected to an AC power supply AC (220 V in this embodiment) and generate high-frequency power.

  As shown in FIG. 2, the glow discharge tube 2 has a structure in which an electrode 12 and a ceramic 13 with an insulating material 11 interposed are attached to a lamp body 10 having a through hole 10a therein by a pressing block 14. A condenser lens 15 is arranged on the side of the spectroscope 7 of the through hole 10a through which the inert gas from the supply unit 6 is guided. The sample 13 is attached to the ceramic 13 in a state where the sample S is pressed by the sample pressing member 9. The sample pressing member 9 also serves as a voltage application electrode, and is connected to the power supply unit 3 by the power supply line D to apply a high frequency voltage to the sample S.

  FIG. 3 shows the internal configuration of the generator 4 constituting the power supply unit 3. The generator 4 of this embodiment includes a high frequency power generation unit 4a, a control unit 4b, and a detection unit 4c. The high frequency power generation unit 4a is connected to the AC power supply AC to generate high frequency power (13.56 MHz in the present embodiment). The high frequency power generation unit 4a is connected to the control unit 4b by the first internal connection line 4d, and starts and ends the generation of the high frequency power and changes the value of the generated high frequency power based on the control of the control unit 4b. .

  The detection unit 4c of the generator 4 is connected to the control unit 4b through the second internal connection line 4e and is connected to the high frequency power generation unit 4a through the third internal connection line 4f, and is generated by the high frequency power generation unit 4a. An average voltage value and a current value relating to a high-frequency voltage (AC voltage) output from the generator 4 toward the sample S according to the high-frequency power are detected. The reason why the voltage value detected by the detection unit 4 is the average voltage value is that the high frequency (alternating current) is alternately switched between positive and negative. In this embodiment, the difference between the amplitude center value and 0 V is used as the average voltage value. Yes. The average voltage value of the sinusoidal alternating current is obtained by “crest value × (2 / π)”. The detection unit 4c also detects the reflected voltage value of the reflected wave reflected from the sample S and transmits the detected average voltage value and reflected voltage value to the control unit 4b.

  The control unit 4 b of the generator 4 is configured by an IC (integrated circuit), and performs control processing related to high-frequency power generation in the generator 4. The reference voltage value is transmitted from the analysis control unit 8 through the first connection cord W1 to the control unit 4b before measurement, and the average voltage value is transmitted from the detection unit 4c through the second internal connection line 4e as needed. The control unit 4b stores the transmitted average voltage value, compares it with the reference voltage value transmitted as needed, and outputs a control instruction to change the power value according to the comparison result to the high frequency power generation unit 4a. is doing. Based on such control of the control unit 4b, the average voltage value related to the AC voltage output from the generator 4 is made constant.

  Further, when the control unit 4b determines that the average voltage value is higher than the reference voltage value as a result of the comparison, the control unit 4b controls the high-frequency power generation unit 4a so that the generated power value is lower than the current value. Further, when it is determined that the average voltage value is lower than the reference voltage value, the control unit 4b controls the high frequency power generation unit 4a so as to increase from the current power value, and further determines that the average voltage value is equal to the reference voltage value. When it does, the high frequency electric power generation part 4a is controlled so that the present electric power value may be maintained.

  Such control of the high-frequency power generation unit 4a by the control unit 4b is continuously performed during power supply to the sample S. Therefore, even when the power supply to the sample S is hindered by the situation during measurement. As shown in FIG. 5, the potential difference Vdc between the sample S and the electrode of the glow discharge tube 2 is kept constant except immediately after the start of power feeding, and the occurrence of sputtering becomes uniform.

  In addition, although the initial value is set in advance for the rate of changing the power value generated by the high-frequency power generation unit 4a by the control unit 4b, the rate of change (0.01% to 30%) or change by the user's operation The numerical value to be set can be set. As described above, when the user sets the ratio numerical value related to the change, the content set through the first connection code W1 is transmitted from the analysis control unit 8 to the control unit 4b. The contents transmitted from the analysis control unit 8 to the control unit 4b include an application start signal and an application stop signal. When the control unit 4b receives the application start signal, the high frequency power generation unit 4a starts generating high frequency power. When the application stop signal is received, the high frequency power generation unit 4a performs control to stop the generation of high frequency power.

  FIG. 5 shows an internal configuration of the matching box 5 constituting the power supply unit 3. The matching box 5 includes a variable capacitor 5a, a motor 5b, and a capacitor control unit 5c. The motor 5b changes the electric capacity of the variable capacitor 5a.

  The variable capacitor 5a adjusts the module and phase of the high-frequency voltage output from the generator 4 by changing its own capacitance according to the driving of the motor 5b. The capacitor control unit 5c is connected to the analysis control unit 8 through the second connection cord W2, and controls the driving of the motor 5b based on a control signal transmitted from the analysis control unit 8 to the matching box 5. Specifically, Controls the drive of the motor 5b so that the reflected voltage value from the sample S is minimized to change the electric capacity of the variable capacitor 5a.

  Further, the gas supply unit 6 shown in FIG. 1 is connected to a cylinder (not shown) filled with an inert gas such as argon gas or a mixed gas of inert gas, etc., and the third connection line W3, and analysis control is performed. An electromagnetic valve (not shown) that opens and closes under the control of the second substrate 17 of the unit 8 and supplies an inert gas from the cylinder is provided. Although not shown in FIG. 1, the glow discharge emission analyzer 1 is also provided with a vacuuming device that sucks the air inside the glow discharge tube 2 and evacuates it before supplying gas from the gas supply unit 6. .

  The spectroscope 7 that measures the light L accompanying sputtering emitted from the glow discharge tube 2 has a first slit 7a that transmits the light L and a diffraction that splits the light L that has passed through the first slit 7a as shown in FIG. A grating 7b, a second slit 7c that transmits light split to a wavelength corresponding to the component to be measured, and a plurality of photomultiplier tubes (photomultiplexers) that continuously measure the intensity of light transmitted through the second slit 7c. 7d. Each photomultiplier tube 7d is connected to the analysis control unit 8 by a connection wire bundle W4 in which a plurality of cords are bundled. In the present invention, the analysis control unit 8 requires a measured value of light intensity through the connection wire bundle W4. It is acquired at the timing.

  On the other hand, a computer is applied to the analysis control unit 8 shown in FIG. The analysis control unit 8 is connected to a connection wire bundle W4 extending from the photomultiplier tube 7d and is attached with a first substrate 16 for obtaining a measurement value in the spectroscope 7, and a first connection extending from the generator 4. The second substrate 17 is mounted for connection with the cord W1, the second connection cord W2 extending from the matching box 5, and the third connection cord W3 extending from the gas supply unit 6. Each of the boards 16 and 17 is connected via an internal bus 8a to a CPU 8b, a hard disk device 8c, and a memory 8d for temporarily storing files and data associated with the processing. The internal bus 8a is connected to the monitor device 8e via the external connection line W5, and a vacuuming device (not shown) is connected to the second substrate 17.

  The second substrate 17 has a processing circuit unit, and performs processing for transmitting content related to power generation to the generator 4 from the content set by the user in the analysis control unit 8, and detects the generator 4. A process of receiving the reflected voltage value detected by the unit 4c, generating a signal notifying the reflected voltage value, and transmitting the signal to the matching box 5 is performed. Note that the second substrate 17 also performs processing for outputting an instruction related to control of the gas supply unit 6 and the vacuuming device. The first substrate 16 corresponds to a measurement value acquisition unit, and has a measurement processing circuit unit, and performs a process of acquiring measurement values from the analyzer 7 at predetermined time intervals.

  The CPU 8b of the analysis control unit 8 performs various processes based on a program stored in the hard disk device 8c. For example, the setting item receiving process for measurement and the operation of each circuit unit of the first substrate 16 and the second substrate 17 are performed. Control and analysis processing for the concentration of elemental components contained in the sample S based on the measurement values acquired by the first substrate 16 are performed. The setting item contents (parameters) related to the measurement are input from the user by an input operation unit (mouse, keyboard, etc.) (not shown) connected to the analysis control unit 8, and set in the monitor device 8e based on the control of the CPU 8b. An item input menu is displayed so that the user can input.

  The setting items include the peak value of the high-frequency voltage, the reference voltage value (usually set to several hundred volts), the ratio (or numerical value) related to the change in the power value, the gas supply pressure of the gas supply unit 6, the measurement time, etc. is there. When the above items are input, the CPU 8b sets the contents and performs control according to the set items. When a measurement start instruction is received from the user, control is performed in the order of evacuation and gas supply. When the gas supply is completed, an application start signal is sent from the second substrate 17 to the generator 4 and the measurement time is determined. Then, control for sending an application stop signal to the generator 4 is performed.

Next, the overall processing flow for the analysis by the glow discharge emission spectrometer 1 having the above-described configuration will be described based on the first flowchart of FIG.
First, in the preparation stage, various parameters are set in the glow discharge emission spectrometer 1 based on user input (S1), and the sample S is a glow discharge tube 2 of the glow discharge emission analyzer 1 as shown in FIGS. (S2).

  Thereafter, the inside of the glow discharge tube 2 is evacuated by a evacuation device, and then an inert gas (argon gas) necessary for measurement is supplied from the gas supply unit 6 (S3). When the supply of the inert gas is completed, an application start signal is sent from the analysis control unit 8 to the generator 4, a high frequency voltage is applied to the sample S, and the sample S is analyzed based on the measurement of the emission intensity (S4).

  In the analysis step (S4), sputtering occurs when argon ions generated from the argon gas supplied to the glow discharge tube 2 collide with the surface of the sample S, and particles containing ions are ejected from the surface of the sample S. When excited in plasma and returned to the ground state, light L specific to the element is emitted. After analyzing the light L with the spectroscope 7 and measuring the intensity of each light, the analysis control unit 8 acquires the measurement value from the spectroscope 7 and analyzes the elements contained in the sample S based on the acquired measurement value. To do. Thereafter, the analysis control unit 8 outputs the analysis result to the monitor device 8e or the like (S5).

The second flowchart of FIG. 7 shows the processing procedure of the glow discharge emission analysis method according to the power value control of the present invention in the analysis stage (S4). Specifically, the sample S is being analyzed (under measurement). ), A series of contents for controlling the change of the power value so that the average voltage value related to the high frequency voltage applied to the sample S is constant, and will be described below along the second flowchart.
First, the detection unit 4c of the generator 4 (see FIG. 3) detects an average voltage value related to the high-frequency voltage of the high-frequency power generated by the high-frequency power generation unit 4a (S10), and then the control unit 4b is detected. The average voltage value is compared with the reference voltage value set by the user (S11).

  When the control unit 4b determines that the average voltage value is lower than the reference voltage value by comparison (S11: low), the initial value or a predetermined value set by the user so that the average voltage value is equal to the reference voltage value. Is given to the high-frequency power generation unit 4a (S12). Further, when the control unit 4b determines that the average voltage value is higher than the reference voltage value by comparison (S11: high), the initial value or the user sets the average voltage value to be equal to the reference voltage value. A control instruction to decrease the power value at a predetermined rate (or a predetermined numerical value) is given to the high-frequency power generation unit 4a (S13). Furthermore, when the control unit 4b determines that the average voltage value is equal to the reference voltage value by comparison (S11: equivalent), no control instruction is given to the high-frequency power generation unit 4a.

  Subsequently, when receiving the control instruction, the high-frequency power generation unit 4a generates the high-frequency power by changing the power value according to the control instruction, and generates the high-frequency power with the current power value when the control instruction is not received. (S14). Finally, the control unit 4b determines whether or not the application stop signal from the analysis control unit 8 has been received (S15). If the application stop signal has not been received (S15: NO), the first average voltage value is detected. Returning to (S10), if an application stop signal is received (S15: YES), the high frequency voltage application process is terminated.

  As described above, the glow discharge emission spectrometer 1 of the present embodiment generates high-frequency power and applies a voltage to the sample S so that the average voltage value is constant, so that the sample S and the electrode 12 shown in FIG. The potential difference Vdc is constant (see FIG. 4), and the load on the sample surface is made uniform to stabilize the generation of sputtering. In addition, the fluctuation of emission intensity is suppressed by stable sputtering, and accordingly, the glow discharge emission analyzer 1 realizes measurement analysis with higher accuracy than the conventional one.

  Next, in order to compare the analysis result of the glow discharge emission spectrometer 1 of the present invention with the conventional apparatus (constant power value), the same test piece is used for the apparatus according to the present invention and the conventional apparatus, respectively. Analysis was carried out. The first sample (sample 1) used for analysis contains 0.337% carbon (Carbon: C), and the second sample (sample 2) contains 0.203% carbon (Carbon: C). Thus, each sample was analyzed five times with the glow discharge emission analyzer 1 and the conventional glow discharge emission analyzer.

  The chart of FIG. 8A shows the analysis result of the glow discharge emission spectrometer 1 of the present invention that changes the power value. The sample 1 is analyzed five times, and the average value for the analysis result is “0.3400 ( %) ”, The standard deviation is“ 0.0003 ”, the coefficient of variation (standard deviation / average value) is“ 0.09 ”, and the average value for the result of analyzing Sample 2 five times is“ 0.2043 (% ) ”, The standard deviation was“ 0.0005 ”, and the coefficient of variation was“ 0.26 ”. Each numerical value is rounded off as appropriate (the same applies hereinafter).

  On the other hand, the chart of FIG. 8B shows the analysis result of the conventional glow discharge emission spectrometer that feeds a constant value of high frequency power to the sample, and the average value for the result of analyzing the sample 1 five times is “0.3415”. (%) ”, The standard deviation is“ 0.0009 ”, the coefficient of variation is“ 0.27 ”, and the average value for the result of analyzing Sample 2 five times is“ 0.2055 (%) ”, and the standard deviation is The coefficient of variation was “0.82”.

  In Sample 1, when the coefficient of variation of the apparatus of the present invention is compared with that of the conventional apparatus, the present invention is “0.09” whereas the conventional coefficient is “0.27”. It was found that the analysis result of the apparatus of the present invention was less varied and stable than the conventional one. Also in Sample 2, when the apparatus of the present invention and the conventional apparatus are compared with respect to the coefficient of variation, the present invention is “0.26”, whereas the conventional apparatus is “0.82”. The numerical value of is less than “one third” of the conventional value, and the present invention also has a stable result with less variation in the analysis result than the conventional value.

  As described above, the glow discharge optical emission analyzer 1 according to the present invention controls the average voltage value of the high-frequency voltage applied to the sample S to be constant, instead of making the power value related to power supply constant. The potential difference applied to S is also constant, and stable and highly accurate analysis can be performed. The glow discharge emission analyzer 1 of the present invention is not limited to the above-described embodiment, and various modifications can be applied.

  For example, as shown in FIG. 9, the application of the high frequency voltage to the sample S may be performed intermittently. In FIG. 9, the time T1 indicates the voltage application state (ON), the time zone obtained by subtracting the time T1 from the time T2 of one cycle indicates the non-application state (OFF), and the average voltage value when each voltage is applied is shown. Keep it constant. By intermittently applying the voltage in this manner, the degree of wear on the sample surface due to sputtering during measurement can be reduced, so that a higher voltage can be applied (because the emission intensity increases with increasing voltage). ), More accurate analysis can be performed.

  In order to perform intermittent application in this way, the analysis control unit 8 selects the intermittent application mode for performing intermittent application and the continuous application mode for performing continuous application to the glow discharge emission spectrometer 1 of FIG. It needs to be configured. Further, when the intermittent application mode is selected by the user, the analysis control unit 8 can set the number of times of application (applied frequency) per unit time (one second), such as the time T1 when turned on and the time T2 of one cycle. Thus, the intermittent notification mode selection notification signal, the set times T1 and T2, the number of times of application, and the like are sent to the generator 4.

  Further, when the control unit 4b of the generator 4 shown in FIG. 3 receives the selection notification signal of the intermittent application mode from the analysis control unit 8, the control unit 4b switches to control according to the intermittent application mode, and sets the time T1, T2, and the application The power generation of the high frequency power generation unit 4a is controlled so that the high frequency voltage is applied according to the number of times. Further, in the intermittent application mode, the impedance adjustment process of the matching box 5 cannot be mechanically followed, so that the control unit 4b performs a process related to the adjustment corresponding to the change in the impedance value in software. Therefore, in the intermittent application mode, the variable capacitor 5a of the matching box 5 is controlled by the analysis control unit 8 and the capacitor control unit 5c so that the electric capacity is fixed to a constant value.

  Further, in the intermittent application mode, in addition to making the intermittent application interval the same during the analysis time, it is possible to set and control the duty ratio (time T1 / time T2) to be variable according to the time zone during the analysis time. . For example, as shown in FIG. 10A, the total analysis time Z is divided into a first analysis time z1 and a second analysis time z2, and the second analysis time z2 is changed from the time T1 of the first analysis time z1. Intermittent application may be performed at time T1 ′, and as shown in FIG. 10B, intermittent application is performed at time T2 ′ changed from time T2 of the first analysis time z1 in the second analysis time z2. Also good.

  Furthermore, the voltage value to be applied may be changed according to the state of the sample S for each analysis time zone. For example, as shown in FIG. 11, the voltage is applied at a constant average voltage value D11 during the first analysis time z1. In the second analysis time z2, the measurement is performed at a constant average voltage value D12. In order to apply such a voltage, the average voltage value D12 and each analysis time z1, z2, etc. are set by the analysis control unit 8, the set contents are sent to the generator 4, and the control unit 4b of the generator 4 sets the set contents. The high frequency power generation unit 4a is controlled according to the above. The average voltage value D12 can be set higher or lower than the average voltage value D11. The voltage values D11 and D12 are set in consideration of the material of the sample S, the analysis time, and the like. In addition, the setting according to the time zone of the average voltage value can be applied to both the intermittent application mode and the continuous application mode.

  In the intermittent application mode, the time when the first substrate 16 acquires the measurement value from the spectrometer 7 may be synchronized with the time T1 shown in FIG. By acquiring such measurement values, the first substrate 16 does not acquire measurement values including various noise components that occur when the voltage is not applied (when the voltage is off). Since the noise component is not included, the analysis control unit 8 can perform analysis with higher accuracy. In order for the first substrate 16 to acquire the measurement value from the spectroscope 7 in synchronization with intermittent application, acquisition is performed in accordance with the time T1 set based on the control of the analysis control unit 8, or the generator 4 The control unit 4b sends a notification signal of the application time in accordance with the time at which the high-frequency power generation unit 4a performs the application to the first substrate 16, and the first substrate 16 measures the measurement value in accordance with the timing of receiving the notification signal. To get.

  Further, when the first substrate 16 acquires the measurement value in synchronization with the intermittent application timing, the measurement value is acquired a plurality of times (15 times C1 to C15 in the figure) every time T1 as shown in FIG. You may do it. When the measurement values are acquired a plurality of times as described above, the measurement can be completed in a short time before the degree of wear of the sample S due to sputtering becomes significant. FIG. 13A is a graph showing the measurement intensity of each measurement value acquired by the first substrate 16 with respect to the time axis t related to power supply, and the measurement intensity acquired in accordance with the time T1 during which intermittent application is performed. Shows the contents of standing in a column. Moreover, FIG.13 (b) is the graph which expanded the part with respect to one time T1 in Fig.13 (a), and is a line segment which connected the value measured by C1-C15 at the time of 15 acquisitions. .

  In the graph of FIG. 13A, the measurement intensity is divided with respect to the time axis t. Therefore, in order to make it easier for the user to grasp the contents of the graph, as shown in the graph of FIG. It is preferable to extract and connect only the corresponding measurement values. Such graph conversion processing is performed by the CPU 8b of the analysis control unit 8 based on a program stored in the hard disk device 8c.

  In the graph of FIG. 14, a time T3 on the time axis t is a time obtained by multiplying each time T1 when the measurement is performed by the number of times of application, and by integrating the measured intensity of each measured value and dividing by the time T3. An average measurement value with respect to the total application time can be calculated, and an average measurement value with respect to the total number of measurements can also be calculated by integrating the measurement intensities of the respective measurement values and dividing by the total number of measurements. By calculating various average measured values in this way, the sample S can be analyzed more easily.

1 is an overall schematic diagram of a glow discharge emission spectrometer according to an embodiment of the present invention. It is a schematic sectional drawing of a glow discharge tube. It is a block diagram which shows the internal structure of a generator. It is a graph which shows the electric potential difference between a sample and an electrode. It is a block diagram which shows the internal structure of a matching box. It is a 1st flowchart which shows the whole process sequence of a glow discharge optical emission analyzer. It is a 2nd flowchart which concerns on the glow discharge luminescence analysis method which concerns on application of a fixed average voltage value. (A) is a graph which shows the analysis result by the glow discharge emission analyzer of embodiment, (b) is a chart which shows the analysis result by the conventional glow discharge emission analyzer. It is a graph which shows the voltage application form in intermittent application mode. (A) (b) is a graph which shows the voltage application form of the modification of an intermittent application mode. It is a graph which shows the voltage application form in the case of changing the voltage value to apply according to a time slot | zone. It is a graph which shows the time of acquisition of the measured value during intermittent application. (A) is a graph which shows the measurement intensity | strength of the measured value in an intermittent application mode, (b) is the graph which expanded the part with respect to time T1 of (a). It is the graph which connected each measured value. It is a graph which shows the electric potential difference between the sample and electrode in the conventional glow discharge emission spectrometer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glow discharge luminescence analyzer 2 Glow discharge tube 3 Power supply part 4 Generator 4a High frequency electric power generation part 4b Control part 4c Detection part 5 Matching box 5a Variable capacitor 5b Motor 5c Capacitor control part 6 Gas supply part 7 Spectrometer 8 Analysis control part 8b CPU
S Sample Vdc Potential difference

Claims (2)

In a glow discharge optical emission spectrometer for measuring the intensity of light emission with an AC voltage of the AC power supply unit is generated glow discharge was generated by applying to the analyte material by a spectrometer,
Means for storing a reference voltage value;
Intermittent application means for intermittently applying an alternating voltage to the material to be analyzed at predetermined intervals;
Detecting means for detecting an average voltage value related to an alternating voltage applied to the material to be analyzed;
Comparison means for comparing the average voltage value and the reference voltage value detected by the detection means;
Judgment means for judging the comparison result of the comparison means;
Power control means for performing control to change the power value of the AC power generated by the power supply unit according to the determination result of the determination means so that the average voltage value related to the AC voltage applied to the analyte is constant ;
Glow discharge optical emission spectrometer, characterized in that it comprises a. The glow discharge emission spectrometer according to claim 1 , further comprising measurement value acquisition means for acquiring a value measured by the spectrometer in synchronization with intermittent application performed by the intermittent application means.

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