JP3291253B2 - X-ray fluorescence analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the intensity of fluorescent X-rays generated by irradiating a sample with primary X-rays and obtaining the concentration of an element in the sample based on the measured intensity.
The present invention relates to a line analyzer.

[0002]

2. Description of the Related Art Conventionally, a sample is irradiated with primary X-rays,
There is so-called fluorescent X-ray analysis in which the intensity of fluorescent X-rays generated from an element in a sample is measured, and the concentration (content) of the element in the sample is determined based on the measured intensity. This fluorescent X
In the case of performing so-called background removal by linear analysis, when the sample is high in concentration and the peak intensity is large for the element to be analyzed, the ratio with the background intensity is large, and the measurement time of the background intensity is also high in accuracy. May be shorter than the measurement time of the peak intensity. on the other hand,
When the element to be analyzed is a trace element, the peak position (spectral angle corresponding to the wavelength) and the background position are usually almost the same, and the background intensity measurement time is set to be the same as the peak intensity measurement time. Is appropriate. That is, each measurement time of the peak intensity and the background intensity should be optimally determined in consideration of the element concentration in the sample and the analysis accuracy.

[0003]

However, the conventional fluorescent X
In the line analysis, for example, a method of uniformly measuring the peak intensity and the background intensity at a predetermined measurement time without taking into account, for example, the element concentration in the sample, is employed. In this case, sufficient analysis accuracy may not be obtained or useless measurement time may be consumed. Also <br/> was also need to measurement time is considered so not unrealistically long.

The present invention has been made in view of the above-mentioned conventional problems. In so-called X-ray fluorescence analysis, an appropriate time and analysis accuracy are specified in accordance with a designated total measurement time and analysis accuracy, and further, depending on an element concentration in a sample. It is an object of the present invention to provide an apparatus for automatically performing measurement in a computer.

[0005]

[0006]

[0007]

[0008]

[0009]

[0010]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
In the fluorescent X-ray analyzer according to the first aspect, first, the sample is fixed.
A sample stage, an X-ray source for irradiating the sample with primary X-rays,
Detecting means for measuring the intensity of secondary X-rays generated from the sample;
Is provided. Further, the apparatus includes the following fourth measuring means, third calculating means, and fifth measuring means. The fourth measuring means irradiates the sample with primary X-rays from the X-ray source, and determines a background intensity at a designated peak measurement time for a fluorescent X-ray generated from an element in the sample. The measurement is performed by the detection means in the provisional measurement time. The third calculating means includes a peak measurement intensity and a background provisional measurement intensity measured by the fourth measuring means, and the designated
The best total measurement time based on the peak measurement time
Peak measurement time and background for high accuracy
The background measurement time is calculated from the relational expression when distributing to the background measurement time. The fifth measuring means irradiates the sample with primary X-rays from the X-ray source, and calculates the background intensity of the fluorescent X-rays based on the background measurement time calculated by the third calculating means. To measure.

According to the first aspect of the present invention, the peak intensity is measured at a designated peak measurement time, and the background intensity is measured with respect to the peak measured intensity and the background temporary measured intensity and the designated peak measured intensity .
Based on the peak measurement time, adjust the total measurement time to the best
Peak measurement time and background measurement
The background measurement time is calculated from the relational expression when distributing to a fixed time, and the measurement is performed using the background measurement time.Therefore, an appropriate time and analysis can be performed according to the specified peak measurement time and the element concentration in the sample. Measurement with precision can be performed automatically.

[0012]

[0013]

According to a second aspect of the present invention, there is provided an X-ray fluorescence spectrometer which comprises a sample stage, an X-ray source, and a detecting means.
And Further, the following first measuring means and first calculating means
A step, a second calculating means and an eighth measuring means. The said
1 The measuring means irradiates the sample with primary X-rays from the X-ray source.
The peak intensity of the fluorescent X-rays generated from the elements in the sample.
Degree and background intensity at a given preliminary measurement time
The measurement is performed by the detecting means. The first calculation unit is configured to calculate the first
1) The provisional measured intensity and the peak
The specified total based on the background preliminary measurement intensity
Peak at which the best analysis accuracy is obtained during the measurement time
Calculate the measurement time and background measurement time.
The second calculating means is measured by the first measuring means.
Peak measured intensity and background measured intensity
The relative accuracy of the specified net strength based on
The peak measurement time and the total measurement time
Calculate the background measurement time. The eighth measuring means irradiates the sample with primary X-rays from the X-ray source when the total measuring time calculated by the second calculating means is equal to or less than a specified total measuring time. The detection unit measures the peak intensity and the background intensity of the X-ray with the peak measurement time and the background measurement time calculated by the second calculation unit, while the total measurement time calculated by the second calculation unit is set. If the time is longer than the designated total measurement time, the sample is irradiated with primary X-rays from the X-ray source, and the peak measurement time and the background measurement time calculated by the first calculation means are used as the detection means. To measure.

According to the second aspect of the present invention, the relative accuracy of the specified net intensity is obtained based on the peak temporary measurement intensity and the background temporary measurement intensity, and the peak measurement time at which the total measurement time is the shortest. Then, the background measurement time is calculated, and when the total measurement time is equal to or less than the specified total measurement time, the measurement is performed at each calculated measurement time. On the other hand, if the total measurement time is longer than the designated total measurement time, the peak at which the best analysis accuracy is obtained in the designated total measurement time is determined based on the peak provisional measurement intensity and the background provisional measurement intensity. The measurement time and the background measurement time are calculated, and the measurement is performed at each of those measurement times. Therefore, it is possible to automatically perform measurement with appropriate time and analysis accuracy according to the specified relative accuracy of the net strength and the total measurement time, and the element concentration in the sample.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to an embodiment of the present invention will be described below. First, the configuration of this device will be described with reference to FIG. The apparatus first includes a sample stage 8 on which a sample 3 is fixed, an X-ray source 1 for irradiating the sample 3 with primary X-rays 2, and a detection device for measuring the intensity of a secondary X-ray 6 generated from the sample 3. Means 10. The detection means 10
A spectroscope 5 for separating the secondary X-rays 4 generated from the sample 3,
It comprises a detector 7 for measuring the intensity of the secondary X-ray 6 for each wavelength separated by the spectroscope 5. This device is a so-called scan type device in which the spectroscope 5 and the detector 7 are linked by a goniometer. In addition, the apparatus includes the following first measuring means 12, fourth measuring means 14, sixth measuring means 15,
Calculating means 16, second calculating means 17, third calculating means 18,
Fourth calculating means 19, second measuring means 20, third measuring means 2
A control unit 25 including a first, a fifth measuring unit 22, a seventh measuring unit 23, and an eighth measuring unit 24 is provided.

The first measuring means 12 and the fourth measuring means 1
Fourth, the sixth measuring means 15 applies the primary X-ray to the sample 3 from the X-ray source 1.
The X-rays 2 are irradiated and the peak intensity of the fluorescent X-rays 4 generated from the elements in the sample 3 are detected as follows.
Measure to zero. The first measuring means 12 measures the peak intensity and the background intensity at a predetermined temporary measurement time. The fourth measuring means 14 causes the peak intensity to be measured at a designated peak measurement time and the background intensity to be measured at a predetermined temporary measurement time. The sixth measuring means 15 measures the peak intensity at a predetermined temporary measurement time.

The first calculating means 16 and the second calculating means 1
7. The third calculating unit 18 and the fourth calculating unit 19 calculate the peak measurement time and the like based on the intensity measured by the first measuring unit 12 and the like, respectively, as described below. The first calculation means 16 calculates a peak measurement time at which the best analysis accuracy is obtained in a designated total measurement time based on the peak provisional measurement intensity and the background provisional measurement intensity measured by the first measurement means 12. And the background measurement time is calculated. The second calculating means 17
Is based on the peak temporary measurement intensity and the background temporary measurement intensity measured by the first measurement unit 12,
The peak measurement time and the background measurement time at which the relative accuracy of the specified net strength is obtained and the total measurement time is the shortest are calculated.

The third calculating means 18 calculates the peak measured intensity and the background temporary measured intensity measured by the fourth measuring means 14 and the designated peak measured intensity.
Based on the time, the total measurement time is obtained with the best accuracy
Minutes for peak and background measurements
The background measurement time is calculated from the relational expression at the time of arrangement . The fourth calculator 19 calculates a peak measurement time at which the relative accuracy of the designated peak intensity is obtained, based on the peak temporary measurement intensity measured by the sixth measuring unit 15.

The second measuring means 20 and the third measuring means 2
The first, fifth, seventh and eighth measuring means 22, 23, and 24 irradiate the sample 3 with primary X-rays 2 from the X-ray source 1, respectively, from the elements in the sample 3 as follows. The detecting means 10 measures the peak intensity of the generated fluorescent X-rays 4 and the like. The second measuring means 20 measures the peak intensity and the background intensity based on the peak measuring time and the background measuring time calculated by the first calculating means 12. The third measurement unit 21 measures the peak intensity and the background intensity based on the peak measurement time and the background measurement time calculated by the second calculation unit 17. The fifth measuring unit 22 measures the background intensity based on the background measurement time calculated by the third calculating unit 18.

When the peak measuring time calculated by the fourth calculating means 19 is shorter than the specified peak measuring time, the seventh measuring means 23 measures the peak intensity at the calculated peak measuring time. On the other hand, if the calculated peak measurement time is longer than the specified peak measurement time, the peak intensity is measured at the specified peak measurement time. The eighth measuring means 24 calculates the peak intensity and the background intensity by the second calculating means 17 when the total measuring time calculated by the second calculating means 17 is shorter than the specified total measuring time. When the total measurement time calculated by the second calculation means 17 is longer than the designated total measurement time, the first calculation means 12 is used. The measurement is performed using the peak measurement time and the background measurement time calculated by the above.

Next, the operation of this device will be described.
First, a case of measuring the peak intensity I _P and background intensity I _B for Sample 3, peak measurement time T _P (sec) and the background measurement time T _B (sec)
It will be described to specify the total measuring time T (sec) (T = T P + T B) and. By the operator, that for measuring the peak intensity I _P and background intensity I _B for Sample 3, the total measurement time T specified is inputted to the control unit 25, the first measuring unit 12, the sample 3 X is irradiated with the radiation source 1 from the primary X-rays 2, the peak intensity of the fluorescent X-rays 4 emitted from the element in the sample 3 ^T I _P (cps) and background intensity ^T I _B a (cps), a predetermined short The measurement is performed at a provisional measurement time, for example, 1 (sec) (the subscript ^T indicates provisional measurement).

[0023] Subsequently, the first calculating unit 16, based on the first peak provisional measured intensity measured by the measuring means 12 ^T I _P and background temporarily measurement intensity ^T I _B, designated total measurement time T in calculates the best peak analysis accuracy can be obtained measurement time T _P and background measurement time T _B.

Here, in general, when the number of background measurement points is two or less, the net strength _IN is expressed by the following equation (1). k _B1 and k _B2 are determined from the relationship between the peak position and each background measurement position.

[0025]

(Equation 1)

The total measurement time T (T = _TP + T) of the given peak measurement time and background measurement time
_B1 + T _B2 ), when the best analysis accuracy is obtained, from a statistical point of view, the relationship between each measurement intensity I _P , I _B1 , I _B2 and each measurement time T _P , T _B1 , T _B2 is It is represented by the following equation (2).

[0027]

(Equation 2)

As described above, the following equation (3) holds.

[0029]

(Equation 3)

The accuracy σ _N (cps) of the net strength is represented by the following equation (4).

[0031]

(Equation 4)

[0032] That is, in a predetermined short temporarily measurement time, the peak intensity ^T I _P and background intensity ^T I _B1, ^T I
_{When B2} is measured, the ratio between the respective measurement times T _P , T _B1 , and T _B2 when the best analysis accuracy (net strength accuracy σ _N ) is obtained can be calculated by the equations (2) and (3). By distributing the given total measurement time T, the peak measurement time _TP and the background measurement times T _B1 and T _{B2 at} which the best analysis accuracy σ _N is obtained can be calculated. When the number of background measurement points is one, the third term on the right side of equation (1), the equation on the right side of equation (2), the third term on the right side of equation (3), and equation (4)
May be ignored, in this case, k _B1 =
It is often set to 1. That is, the following equations (5) to (8) are used.

[0033]

(Equation 5)

[0034]

(Equation 6)

[0035]

(Equation 7)

[0036]

(Equation 8)

In the first calculating means 16 of the apparatus of this embodiment, the peak provisional measurement intensity ^T _IP and the background provisional measurement intensity ^T measured by the first measuring means 12 are also used.
Based on the I _B, equation (6), (7), calculates the specified total dispensed the measurement time T, the best analytical precision sigma _N peak measurement time obtained T _P and background measurement time T _B I do. Then, the second measuring means 20 irradiates the sample 3 with primary X-rays 2 from the X-ray source 1, and the peak intensity _IP and the background intensity IP of the fluorescent X-rays 4.
_B is measured by the detection means 10 using the peak measurement time T _P and the background measurement time T _B calculated by the first calculation means 16.

[0038] For example, the total measurement time T = 100 (sec) is designated, a peak temporarily measurement intensity ^T I _P = 40000 (cps)
And background temporarily measurement intensity ^T I _B = 100 (cp
s) is obtained, the first calculating means 16 calculates
From the equations (6) and (7), the peak measurement time T _P = 95 (s)
The ec) and rounded background measurement time T _B = 5 (sec) is calculated (decimal), the second measuring unit 20, the peak intensity I _P and background intensity I _B is measured at each measurement time thereof . At this time, the accuracy σ _N of the net strength is 21.0 (cps) from Expression (8).

This is simply calculated by comparing the peak measurement time T _P and the background measurement time T _B with 50 (sec).
, The net strength accuracy σ _N is 28.3 (cp
become a bad value of s), also, the peak measurement time T _P and the background measurement time T _B in the same time,
In order to obtain the accuracy of 21.0 (cps) equivalent to the apparatus of the present embodiment, a long measurement time of 182 (sec) is required, and 182-100 = 82 (sec) is wasted.

[0040] That is, the apparatus according to the present embodiment, based on a peak temporarily measurement intensity ^T I _P and background temporarily measurement intensity ^T I _B, in the specified total measurement time T was, the best analytical accuracy sigma _N Obtained peak measurement time T
_P and the background measurement time T _B are calculated, and the measurement is performed at each of the measurement times T _P and T _B , so that the specified total measurement time T and the element concentration in the sample 3 (the peak temporary measurement intensity ^T _IP and Background preliminary measurement intensity ^TI
Depending on the magnitude relationship with _B ), it is possible to automatically perform measurement with appropriate time and analysis accuracy.

Next, a case of measuring the peak intensity I _P and background intensity I _B for Sample 3,
The case where the relative accuracy σ _R of the net strength is specified will be described. By the operator, that for measuring the peak intensity I _P and background intensity I _B, if the relative accuracy sigma _R net intensity of specified is inputted to the control unit 25, the total measurement time T described above is designated Like the first measurement means 12, it is measured in the detection means 10 the peak provisional measured intensity ^T I _P and background temporarily measurement intensity ^T I _B.

[0042] Then, the second calculation means 17, based on the measured peak temporarily measurement intensity ^T I _P and background temporarily measurement intensity ^T I _B by the first measuring means 12, the relative accuracy of the given net intensity The peak measurement time T _P and the background measurement time T _{B at} which σ _R is obtained and the total measurement time T is the shortest are calculated as follows.

First, the net strength _IN is obtained from the previous equation (5), and is substituted into the following equation (9) to calculate the net strength precision σ _N corresponding to the specified net strength relative precision σ _R. .

[0044]

(Equation 9)

Using the accuracy σ _{N of the} net strength, the following expressions (6) and (8), and the following expression (1)
The 0), obtained relative precision sigma _R of the specified net intensity, and total measurement time T peak measurement time becomes shortest T _P and background measurement time T _B is calculated. Then, the third measuring means 21 outputs the second
Similar to the measuring means 20, the X-ray source 1 to the sample 3 is irradiated with the primary X-rays 2, the peak intensity of the fluorescent X-ray 4 I _P and background intensity I _B, calculated peak measurement time T _P and the background measurement time T _B, is measured to the detection means 10.

[0046]

(Equation 10)

As described above, according to the apparatus of this embodiment,
Peak provisional measurement intensity ^T _IP , background provisional measurement intensity
Based on ^T I _B, relative accuracy of the given net strength σ
_The peak measurement time T _P and the background measurement time T _{B at} which _R is obtained and the total measurement time T is the shortest are calculated, and the measurement is performed at each of these measurement times T _P and T _B. Relative accuracy of net strength σ _R and sample 3
The measurement can be automatically performed with appropriate time and analytical accuracy according to the element concentration in the sample.

Next, a case of measuring the peak intensity I _P and background intensity I _B for Sample 3,
The case where the peak measurement time _TP is designated will be described.
By the operator, that for measuring the peak intensity I _P and background intensity I _B, peak measurement time T _P of the specification,
When input to the control means 25, the fourth measuring means 14 irradiates the sample 3 with the primary X-rays 2 from the X-ray source 1, and the sample 3
A fluorescent X-ray peak measurement time T _P to the specified peak intensity I _P of generated from elements in the background intensity ^T
The I _B is measured in the detection unit 10 at a predetermined provisional measurement time.

Subsequently, based on the peak measured intensity IP measured by the fourth measuring unit and the background provisional measured intensity TIB, the third calculating unit 18 calculates the peak measuring time TP specified by the above equation (6). Is calculated for the background measurement time TB at which the best accuracy .sigma.N is obtained with respect to the total measurement time T. That is,
4 The peak measurement intensities IP and
And background preliminary measurement intensity TIB and the above
Total measurement based on the specified peak measurement time TP
Time T is the peak measurement time at which the best accuracy σN is obtained
Distribute to TP and background measurement time TB
(6), the background measurement time
Calculate TB. Then, the fifth measuring unit 22 irradiates the sample 3 with the primary X-ray 2 from the X-ray source 1 and calculates the background intensity IB of the fluorescent X-ray 4 by the third calculating unit 18.
With the background measurement time TB calculated by
The detection means 10 is caused to measure.

For example, for sample 3 with a high concentration,
Measurement time T_P= 40 (sec) is specified and the peak measurement intensity
I_P= 40000 (cps) and provisional background measurement
Strength ^TI_B= 100 (cps), the third calculation
In the delivery means 18, according to equation (6), the background
Measurement time T_B= 2.0 (sec) is calculated and the fifth measurement
The measurement time T_BWith strong background
Degree I_BIs measured. The accuracy σ of the net strength at this time_N
Is 32.4 (cps) according to equation (8). this,
Simply, the background measurement time T_BAlso during peak measurement
Interval T_PWhen measured at 40 (sec), the same as
Degree σ_NIs almost unchanged at 31.7 (cps),
(40 + 40) − (40 + 2) = 38 in total measurement time T
(sec) is unnecessarily long.

For the low concentration sample 3, a peak measurement time T _P = 50 (sec) is designated and the peak measurement intensity I _P
= 120 (cps) and background provisional measured intensity ^T I
Assuming that _B = 100 (cps) is obtained, the third calculating means 1
In 8, a background measurement time T _B = 46 (se
c) is calculated, by the fifth measuring means 22, in the background measurement time T _B is the background intensity I _B is measured. The accuracy σ _N of the net strength at this time is:
1 (cps). Even if this is simply measured at the same 50 (sec) as the background measurement time T _B and the peak measurement time T _P , the accuracy σ _{N of the} net strength is still 2.1 (cp
s), the total measurement time T is (50 + 5)
0)-(50 + 46) = 4 (sec).

As described above, according to the apparatus of the present embodiment,
The peak intensity IP is measured at the designated peak measurement time TP, and the background intensity IB is measured at the peak measured intensity IP, the background temporary measured intensity TIB, and the designated peak measurement time TP.
Based on the fixed time TP, the total measurement time T is
Peak measurement time TP and back to obtain degree σN
Relational expression when distributing to ground measurement time TB
From (6), the background measurement time TB is calculated, and the measurement is performed with the background measurement time TB. Therefore, the specified peak measurement time TP and the element concentration in the sample 3 (the peak measurement intensity IP and the background temporary measurement intensity Depending on the magnitude relationship with TIB), measurement with appropriate time and analysis accuracy can be performed automatically. In addition, since the provisional measurement is performed only for the background intensity, there is an advantage that the goniometer needs to be driven less in the entire measurement.

Next, the case where only the peak intensity I _P is measured for the sample 3 is shown, and the relative accuracy σ _R of the net intensity and the upper limit ^L T _P of the peak measurement time (the subscript ^L indicates the upper limit value). ) Will be described. First, the operator, that the measure only peak intensity I _P,
The upper limit ^L T _P of relative precision sigma _R and peak measurement time specified net intensity is input to the control unit 25.

Here, the upper limit of the peak measurement time to be specified
^L T _P can be determined as follows. First, in this measurement, assuming that there is a linear relationship between the concentration and the peak intensity, the concentrations are 0.01 mass% and 5.0 ma, respectively.
The peak intensities I _0.01 and I _5.0 in the ss% sample are expressed by the following equations (11) and (12).

[0055]

[Equation 11]

[0056]

(Equation 12)

[0057] Ryoshikichu, R _1.0 is a net intensity per concentration 1 mass% (cps), the background intensity when R _B is that irrelevant to the concentration (cps), using a standard sample, for example, R _1.0 = 10000 and R _B = 100.

Now, the relative accuracy σ _R of the net intensity when the background is not removed is equal to the accuracy σ _{P of the} peak intensity.
Is expressed by the following equation (13), and the accuracy σ _{P of the} peak intensity is
Is further expressed by the following equation (14).

[0059]

(Equation 13)

[0060]

[Equation 14]

Further, using the above equation (5), the following equation (1)
5) is obtained.

[0062]

(Equation 15)

Now, the desired relative accuracy σ _R to be designated
Is 0.002, for example, a concentration of 5.0 mass
%, The peak measurement time T _P (in this case, ie, the entire measurement time) is obtained from Expressions (15) and (12) as shown in Expression (16), and the measurement is performed in a sufficiently short time. It can be confirmed that it is enough.

[0064]

(Equation 16)

On the other hand, for example, for a sample having a concentration of 0.01 mass%, when the desired relative accuracy σ _R is reduced to 0.01, the following equation (17) is obtained from equations (15) and (11). ), The peak measurement time _TP is obtained.

[0066]

[Equation 17]

On the other hand, even if there is a sample having a concentration of less than 0.01 mass%, the desired relative accuracy σ
When it is considered that it is not meaningful to measure with the peak measurement time T _P exceeding 200 (sec), sticking to _R = 0.01, 200 (sec) is set to the upper limit of the peak measurement time.
It may be designated as the ^L T _P.

[0068] In this way, by the operator, that the measure only peak intensity I _P, the upper limit ^L T _P of relative precision sigma _R and peak measurement time of the net intensity of the specified, the control means 2
Is input to the fifth and sixth measuring device 15, the X-ray source 1 to the sample 3 is irradiated with the primary X-rays 2, the peak intensity ^T I _P of the fluorescent X-ray generated from the elements of the sample 3 The detection means 10 is caused to measure at a predetermined temporary measurement time. Subsequently, the fourth calculating means 19, the sixth on the basis of the measured peak temporarily measurement intensity ^T I _P by the measuring means 15, a peak measurement time T _P in which relative accuracy sigma _R of the specified net strength can be obtained, The previous equation (1
It is calculated by 5). It should be noted that the background intensity I _B
For, it is possible to use the aforementioned R _B obtained using the standard sample.

[0069] Then, the seventh measurement unit 23, if the fourth peak measurement time peak calculated measurement time T _P is specified by the calculation unit 19 is ^L T _P below, X-rays source 1 to the sample 3 Irradiates the primary X-ray 2 from the detector, and causes the detecting means 10 to measure the peak intensity I _P of the fluorescent X-ray 4 at the calculated peak measurement time T _P , while the calculated peak measurement time T _P is designated. and it is longer than the peak measured time ^L T _P causes similarly measured at the time specified peak measurement ^L T _P.

For example, as described above, R _1.0 = 100
00, R at _B = 100, the relative accuracy sigma _R net intensity 0.01, if the upper limit ^L T _P of the peak measurement time is designated 200, accuracy and peak measurement time concentration on the sample 3 of each concentration Is as shown in Table 1 below. Note that the density accuracy (mass%) is obtained by multiplying the net accuracy relative accuracy σ _R (also the density accuracy) by the density.

[0071]

[Table 1]

[0072] As described above, the apparatus according to the present embodiment, based on a peak temporarily measurement intensity ^T I _P, to calculate the peak measurement time T _P for the given relative accuracy sigma _R is obtained, it is designated It has been when the peak measurement time is less than ^L T _P is calculated peak measured time measured by T _P, is longer than the specified peak measurement time ^L T _P is the designated peak measurement time since the measurement by ^L T _P, the specified relative precision sigma _R and peak measurement time ^L T _P, and in response to the element concentration in the sample 3, it is performed automatically measured at appropriate time and analysis accuracy it can. That is,
As shown in Table 1, at low concentrations, the specified peak measurement time ^L _TP is prioritized and the realistic and practical measurement time
^L T _P , at high concentrations, the specified relative accuracy σ _R
With no wasted measurement time and its relative accuracy σ _R
Can be automatically measured in the shortest measurement time _TP at which is obtained.

The relative accuracy of the peak intensity (gross intensity) can be considered instead of the relative accuracy of the net intensity. In this case, the following equations (18) and (19) are used instead of the previous equations (13) and (15).

[0074]

(Equation 18)

[0075]

[Equation 19]

As a matter of fact, even if the one corresponding to Table 1 is created by using the equation (19), the one having almost no difference can be obtained. In this case, the equation (18) is replaced by the equation (14).
And the following equation (20) is obtained, and the reciprocal of the square root of the integrated intensity (total count) N can be used as the relative accuracy σ _R. That is, the integrated intensity N
Has the same meaning as the designation of the relative accuracy σ _R, and the “designated relative accuracy” described in claim 4 of the present application includes the “designated integrated intensity”.

[0077]

(Equation 20)

Next, a case of measuring the peak intensity I _P and background intensity I _B for Sample 3,
The upper limit of the relative accuracy sigma _R and peak measurement time of the net intensity T _P and background measurement time total measurement time of T _B
^The case where LT is specified will be described. By the operator,
That for measuring the peak intensity I _P and background intensity I _B, relative precision sigma _R and an upper limit ^L T total measurement time of the net intensity of the specification is inputted to the control unit 25, only the total measurement time T described above Is specified,
Said first measuring means 12, is measured in the detection means 10 the peak provisional measured intensity ^T I _P and background temporarily measurement intensity ^T I _B.

Subsequently, the relative accuracy σ of the net strength described above
_RAs in the case where only the second calculating means 17 is designated,
Is a tentative measurement of the peak measured by the first measuring means 12.
Constant strength ^TI_PAnd background preliminary measurement intensity^TI_B
Based on the relative accuracy σ of the specified net strength_RGet
And total measurement time^TwoT (^TwoT =^TwoT_P+
^TwoT_B) Is the shortest peak measurement time^TwoT_PAnd battery
Background measurement time^TwoT_BIs calculated.

The first calculating means 16 also calculates the peak temporary measurement intensity ^T _IP and the background temporary measurement intensity measured by the first measuring means 12 in the same manner as when only the total measurement time T is specified. based on ^T I _B, it distributes the specified total measurement time ^L T was the best analytical accuracy sigma _N
Is calculated, and the peak measurement time ¹ T _P and the background measurement time ¹ T _B are calculated. Note that the suffixes ¹ and ² indicate values calculated by the first calculating means 16 and the second calculating means 17, respectively.

[0081] Then, the eighth measuring means 24, when the total measuring time ² T calculated by the second calculating means 17 is less than the specified total measured time ^L T from X-ray source 1 to the sample 3 is irradiated with primary X-rays 2, it is measured in the detection unit 10 by the peak intensity I _P and background intensity I _B of peak measurement time calculated by the second calculating means 17 ² T _P and background measurement time ² T _B On the other hand, if the total measurement time ² T calculated by the second calculation means 17 is longer than the specified total measurement time ^LT , the peak measurement time ¹ T _P calculated by the first calculation means 16 and the back ground measurement time is measured at ¹ T _B.

The relative accuracy σ _R of the net strength and the upper limit ^{LT of the} total measurement time are specified, for example, as in the case of using the above-mentioned seventh measuring means 23, where R _1.0 = 1.
Assuming that the desired relative accuracy σ _R is 0.002 for a sample having a concentration of 5.0 mass% and 0000, R _B = 100,
From the equations (10) and (6), the peak measurement time T _P and the background measurement time T _{B are} calculated as in the following equation (21).
Is required, and it can be confirmed that a sufficiently short total measurement time is sufficient.

[0083]

(Equation 21)

On the other hand, for a sample having a concentration of 0.01 mass%, when the desired relative accuracy σ _R is reduced to 0.02, from the equations (10) and (6), the following equation (22) is obtained. like,
Peak measurement time T _P and background measurement time T
_B is calculated and rounded to the nearest decimal point.
The total measurement time T is 145 (sec).

[0085]

(Equation 22)

On the other hand, even if there is a sample having a concentration of less than 0.01 mass%, the desired relative accuracy σ
To stick to the _R = 0.02, when considered much sense not to be measured by the total measurement time T exceeding 145 (sec) is, by specifying 145 (sec) as the upper limit ^L T Total measurement time Good.

As for the actual measurement,
_1.0 = 10000, with R _B = 100, the relative accuracy sigma _R net strength 0.01, the upper limit ^L T total measurement time is 14
When designated as 5, the concentration accuracy, peak measurement time and background measurement time for each concentration of the sample are
Table 2 below.

[0088]

[Table 2]

As described above, according to the device of the present embodiment,
Peak provisional measurement intensity ^T _IP , background provisional measurement intensity
Based on ^T I _B, relative accuracy of the given net strength σ
_R is obtained and the peak measurement time ² total measuring time ² T is the shortest T _P and background measurement time ² T
_B is calculated, and if the total measurement time ² T is less than or equal to the specified total measurement time ^LT , each calculated measurement time
Make measurements at ² T _P, ² T _B. On the other hand, the total measurement time ² T
Is longer than the specified total measurement time ^LT , the peak provisional measurement intensity ^T _IP and the background provisional measurement intensity ^T
Based on the I _B, in the specified total measurement time ^L T has a peak measurement time best analytical precision sigma _N is obtained ¹
Calculating the T _P and background measurement time ¹ T _B,
They perform measurements at each measurement time ¹ T _P, ¹ T _B of. Therefore, the relative accuracy sigma _R and total measurement time ^L T of the specified net strength, and depending on the element concentration in the sample 3, it is possible to automatically perform measurements at appropriate time and analysis accuracy.

That is, as shown in Table 2, at a low concentration, a specified realistic and practical total measurement time ^LT
, The peak measurement time ¹ T _P and the background measurement time ¹ T at which the best analysis accuracy σ _N is obtained.
_{In B,} at a high concentration, the specified relative accuracy σ _R is prioritized, and the shortest peak measurement time ² T _P and background measurement time ² T at which the relative accuracy σ _R can be obtained without wasting measurement time. _{At B} , measurements can be taken automatically.

[0091]

As described above in detail, according to the present invention, in X-ray fluorescence analysis, an appropriate time and analysis accuracy can be set in accordance with a designated total measurement time and analysis accuracy, and further, depending on the element concentration in a sample. Measurement can be performed automatically.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an X-ray fluorescence analyzer according to one embodiment of the present invention.

[Explanation of symbols]

1: X-ray source, 2: primary X-ray, 3: sample, 4, 6: secondary X
X-ray (fluorescent X-ray), 8: sample stage, 10: detecting means, 12:
1st measuring means, 14 ... 4th measuring means, 15 ... 6th measuring means, 16 ... 1st calculating means, 17 ... 2nd calculating means, 18 ...
Third calculating means, 19: fourth calculating means, 20: second measuring means, 21: third measuring means, 22: fifth measuring means, 23 ...
Seventh measuring means, 24 ... eighth measuring means.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-133910 (JP, A) JP-A-7-63711 (JP, A) Glen F. Noll (translated by Itsuo Kimura and Ei Sakai), Radiation Measurement Handbook, Japan, Nikkan Kogyo Shimbun, 113 (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 23/00-23/227

Claims (2)

(57) [Claims] A sample stage on which a sample is fixed; an X-ray source for irradiating the sample with primary X-rays; detecting means for measuring the intensity of secondary X-rays generated from the sample; Irradiating primary X-rays from a source and causing the detection means to measure the peak intensity of fluorescent X-rays generated from the elements in the sample at a designated peak measurement time and the background intensity at a predetermined temporary measurement time. A fourth measurement means, a peak measurement intensity and a background provisional measurement intensity measured by the fourth measurement means, and the designated
Based on the peak measurement time, adjust the total measurement time to the best
Peak measurement time and background measurement
A third calculating means for calculating a background measurement time from a relational expression at the time of distribution to a fixed time; and irradiating the sample with primary X-rays from the X-ray source,
An X-ray fluorescence analyzer comprising: a fifth measurement unit that causes the detection unit to measure the background intensity of the line at the background measurement time calculated by the third calculation unit. 2. A sample stage on which a sample is fixed; an X-ray source for irradiating the sample with primary X-rays; a detecting means for measuring the intensity of secondary X-rays generated from the sample; A first measuring means for irradiating a primary X-ray from a source and causing the detecting means to measure a peak intensity and a background intensity of a fluorescent X-ray generated from an element in the sample at a predetermined temporary measuring time; Based on the peak temporary measurement intensity and the background temporary measurement intensity measured by the measurement means, the relative accuracy of the specified net intensity is obtained, and the peak measurement time and the background measurement time at which the total measurement time is the shortest are determined. A second calculating unit for calculating, based on the peak provisional measurement intensity and the background provisional measurement intensity measured by the first measurement unit, best in a designated total measurement time. A first calculating means for calculating a peak measuring time and a background measuring time at which an analysis accuracy is obtained; and, if the total measuring time calculated by the second calculating means is equal to or less than a specified total measuring time, the sample The X
Irradiating primary X-rays from a radiation source, and causing the detection means to measure the peak intensity and the background intensity of the fluorescent X-rays at the peak measurement time and the background measurement time calculated by the second calculation means, When the total measurement time calculated by the second calculation means is longer than the specified total measurement time, the sample is irradiated with primary X-rays from the X-ray source, and the sample is calculated by the first calculation means. And an eighth measuring means for causing the detecting means to measure the peak measuring time and the background measuring time.
Line analyzer.