JP2006184258A - Ultrasonic method and ultrasonic apparatus for computing concentration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a computing period and carry out a measurement more precisely in an ultrasonic method and an ultrasonic apparatus for computing a concentration. <P>SOLUTION: In the ultrasonic method for computing the concentration, an ultrasonic wave is transmitted into an solution to be measured, and the ultrasonic wave which propagates through the solution to be measured, is received, and a propagation velocity V is computed from a propagation time and a propagation distance, and a temperature T of the solution to be measured is detected, and (n-1) kinds of specific physical quantities (α<SB>1</SB>-α<SB>n-1</SB>) which are, independently of propagation velocities, affected respectively by solute concentrations and temperatures of the solution to be measured, and also which are, independently of each other, affected by the solute concentrations and the temperature of the solution to be measured, are defined, and a function representing relations of the propagation velocity V of the ultrasonic wave, respective solute concentrations (D<SB>1</SB>-D<SB>n</SB>) and the (n-1) kinds of specific physical quantities (α<SB>1</SB>-α<SB>n-1</SB>) is given as following: V=F<SB>11</SB>(T, D<SB>1</SB>, α<SB>1</SB>-α<SB>n-1</SB>) through V=F<SB>1n</SB>(T, D<SB>n</SB>, α<SB>1</SB>-α<SB>n-1</SB>), α<SB>1</SB>=F<SB>21</SB>(T, D<SB>1</SB>, V, α<SB>2</SB>-α<SB>n-1</SB>) through α<SB>1</SB>=F<SB>2n</SB>(T, D<SB>n</SB>, V, α<SB>2</SB>-α<SB>n-1</SB>), α<SB>2</SB>=F<SB>31</SB>(T, D<SB>1</SB>, V, α<SB>1</SB>, α<SB>3</SB>-α<SB>n-1</SB>) through α<SB>2</SB>=F<SB>3n</SB>(T, D<SB>n</SB>, V, α<SB>1</SB>, α<SB>3</SB>-α<SB>n-1</SB>) through α<SB>n-1</SB>=F<SB>n1</SB>(T, D<SB>1</SB>, V, α<SB>1</SB>-α<SB>n-2</SB>) through α<SB>n-1</SB>=F<SB>nn</SB>(T, D<SB>n</SB>, V, α<SB>1</SB>-α<SB>n-2</SB>), and the solute concentrations (D<SB>1</SB>-D<SB>n</SB>) are computed from the temperature T, the specific physical quantities (α<SB>1</SB>-α<SB>n-1</SB>) and the propagation velocity V, based on the function. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an ultrasonic concentration calculation method and an ultrasonic concentration measurement apparatus. More specifically, the present invention relates to an ultrasonic concentration calculation method and an ultrasonic concentration measurement apparatus that measure each concentration (D ₁ ... D _n ) of a plurality of (n) solutes dissolved in a solvent.

As a conventional technique for measuring each concentration (D ₁ ... D _n ) of a plurality of (n) solutes dissolved in a solvent, liquid chromatography is used. Liquid chromatography makes it possible to measure the concentration of each solute by pouring a sampled solution into a column and separating and quantifying each solute.
The liquid chromatography requires complicated equipment and operation, and requires a lot of labor and time to obtain the concentration of each solute. Further, since liquid chromatography is a sampling measurement method, for example, it is not possible to automatically measure the concentration of a chemical solution in a chemical solution production line or the like online.
Japanese Patent Laid-Open No. 58-77656 (Patent Document 1) proposes a concentration measuring device using ultrasonic waves. This concentration measuring device is a solution in which a single solute is dissolved in a solvent. It is useful only in the concentration measurement of
Japanese Patent Laid-Open No. 63-311166 (Patent Document 2) discloses that each concentration (D) of a plurality of (n) solutes in a multi-component solution obtained by dissolving a plurality (n) of solutes in a solvent using ultrasonic waves (D ₁ ... D _n ) has been proposed. The calculation method in this concentration measuring apparatus uses a temporary concentration (D ₁ ... D _n ) and measured temperature (T) as a function D ₁ = F _1. (V, T, α ₁ ... Α _n-1 ) ... D _n = F _n (V, T, α ₁ ... Α _n-1 ), and the concentration (D ₁ ... D _n ), temperature (T ) Repeated substitution calculation of temporary concentration (D ₁ ... D _n ) so that values (ultrasonic propagation velocity (V), specific physical properties (α ₁ ... α _n-1 )) are as close as possible to actual measured values Thus, the concentration (D ₁ ... D _n ) was calculated, and high-precision measurement with few errors was possible.
JP 58-77656 A JP-A-63-311166

  An object of the present invention is to solve the above-described problems of the prior art, and to reduce the calculation time and achieve more accurate measurement in an ultrasonic concentration calculation method and an ultrasonic concentration measurement apparatus.

The present invention is an ultrasonic concentration measurement method for measuring each concentration (D ₁ ... D _n ) of a plurality (n) of solutes in a multi-component solution obtained by dissolving a plurality (n) of solutes in a solvent. (N-1) kinds of specific physical properties (α ₁ ... α _n-1 ), ultrasonic wave propagation velocity (V), and concentration of each solute, which are influenced independently by the concentration of the solution and the temperature of the solution to be measured Function indicating relationship with (D ₁ ... D _n ) (the following function group is defined as (1))
V = F ₁₁ (T, D ₁ , α ₁ ... Α _n-1 )... V = F _1n (T, D _n , α ₁ ... Α _n-1 )
α ₁ = F ₂₁ (T, D ₁ , V, α ₂ ... α _n-1 )... α ₁ = F _2n (T, D _n , V, α ₂ … α _n-1 )
_{α 2 = F 31 (T,} D 1, V, α 1, α 3 ... α n-1) ··· α 2 = F 3n (T, D n, V, α 1, α 3 ... α n-1 )
・
・
・
α _n-1 = F _n1 (T, D ₁ , V, α ₁ ... α _n-2 )... α _n-1 = F _nn (T, D _n , V, α ₁ ... α _n-2 )
And the temperature (T), the specific physical property amount (α ₁ ... Α _n-1 ), and the propagation velocity (V), the concentration (D ₁ ... D _n ) of each solute is directly calculated based on the function. And

The present invention also relates to a concentration measuring apparatus for measuring each concentration (D ₁ ... D _n ) of a plurality of (n) solutes dissolved in a solvent, wherein the ultrasonic transmission for transmitting ultrasonic waves to a solution to be measured is provided. A wave receiver, an ultrasonic wave receiver that receives ultrasonic waves propagated in the solution to be measured, a velocity calculation unit that calculates a propagation velocity (V) from the propagation time and propagation distance of the ultrasonic wave, A temperature detector that detects the temperature (T), and (n-1) kinds of specific physical property quantities (α ₁ ... Α _n ) that are independently affected by the propagation speed depending on the concentration of each solute and the temperature of the solution to be measured. _-1 ) and (n-1) specific physical quantity detections for detecting specific physical quantity (α ₁ ... Α _n-1 ) that are independently influenced by the concentration of each solute and the temperature of the solution to be measured. And the relationship between the concentration of the solution to be measured (T), the specific physical property amount (α ₁ ... Α _n-1 ), the ultrasonic wave propagation velocity (V), and the concentration of each solute (D ₁ ... D _n ). The function (1) is stored in advance, the output of the temperature detector (α ₁ ... Α _n-1 ) and the output of the velocity calculation unit (V). It is characterized by having a density calculator for calculating the density (D ₁ ... D _n ) and an output device for outputting the calculation result of the density calculator.

In the present invention, for each multi-component solution as a solution to be measured, the temperature (T) of the solution and the specific physical property amount (α ₁ ... Α _n− ) such as density (ρ) or conductivity (σ). ₁ ), a function equation (1) indicating a relationship between the ultrasonic wave propagation velocity (V) and the concentration (D ₁ ... D _n ) of each solute is determined in advance and stored in the storage unit. Thus, the temperature detector and the specific physical quantity detector detect the temperature (T) and the specific physical quantity (α ₁ ... Α _n-1 ) of the solution to be measured, and the velocity calculation unit transmits the ultrasonic wave propagation speed. By calculating (V) and substituting these detection results and calculation results into the aforementioned function, the concentration (D ₁ ... D _n ) of each solute can be reliably and easily measured.
The specific physical properties used in the practice of the present invention are not limited to conductivity and density, but include PH, light refractive index, radiation attenuation factor, ultrasonic frequency used, and third solute addition to the solution to be measured. The amount etc. can be widely adopted. For example, in a multi-component solution in which n = 3 types of solutes are dissolved in a solvent, n−1 = 2 types of specific physical properties are used. If the density (ρ) is selected, the concentrations D ₁ , D ₂ , and D ₃ of each solute are calculated by the following function.

FIG. 1 is a block diagram showing an ultrasonic concentration measuring apparatus according to an embodiment of the present invention, FIG. 2A is a front view showing a sensor used for carrying out the present invention, and FIG. 2) is a cross-sectional view taken along line BB in FIG. 2, FIG. 2C is a cross-sectional view taken along line CC in FIG. 2A, and FIG. 3 is a flowchart showing a state of transmitting and receiving ultrasonic waves.
The ultrasonic concentration measuring device 10 measures the concentration of each solute in a multi-component solution obtained by dissolving a plurality of (n) solutes in a solvent, and includes an arithmetic device 11 (see FIG. 1) and a sensor 12 (see FIG. 2). The arithmetic unit 11 is additionally provided with a display 13.

The sensor 12 is used by being put into the solution 1 to be measured. The sensor 12 includes an ultrasonic transmitter / receiver (vibrator) 14 that also serves as an ultrasonic transmitter and an ultrasonic receiver, and a reflector 15. The ultrasonic wave transmitted from the ultrasonic transducer 14 to the solution 1 to be measured propagates through the solution 1 to be measured, is reflected by the reflecting plate 15, and is received by the ultrasonic transducer 14.
The sensor 12 includes a temperature detector 16 made of a thermistor, and detects the temperature (T) of the solution 1 to be measured.
Further, the sensor 12 is affected by the concentration of each solute dissolved in the solution to be measured 1 and the temperature (T) of the solution to be measured. (N-1) kinds of specific physical properties (α ₁ ... α _n− ) which are specific physical properties (α ₁ ... Α _n−1 ) and are independently influenced by the concentration of each solute and the temperature of the solution to be measured. ₁ ) A specific physical property detector for detecting ₁ ) is provided. If the solution 1 to be measured is, for example, one in which two solutes are dissolved (for example, an aqueous solution of NaOH and NaCl), the sensor 12 includes a conductivity detector 17 that detects one kind of specific physical property amount, for example, conductivity σ. Prepare.

The computing device 11 includes a sing-around unit 18, a temperature measurement unit 19, a conductivity measurement unit 20 as an example of a specific physical property measurement unit, an input / output unit 21, a CPU 22, a ROM 23, and a RAM 24.
The detected amount of the ultrasonic transducer 14 is transferred to the CPU 22 via the sing-around unit 18 and the input / output unit 21, and the ultrasonic propagation velocity (V) is calculated and calculated by the CPU 22 as a speed calculation unit. The speed data (V) is stored in the RAM 24. In the sing-around method, ultrasonic waves are transmitted and transmitted again after τ ₀ seconds after receiving the reflected wave, and transmitted after τ ₀ seconds after receiving the reflected wave. This is a method for measuring the propagation velocity (V) of. In FIG. 3, A is a transmission wave and B is a reception wave. If the time from an arbitrary transmission time point until (k + 1) transmissions are performed is t (see C in FIG. 3), and P = t / k obtained by calculation is data P, the propagation speed ( V) is given by:
_{V = 2L 0 / (P-} τ 0)
Here, L ₀ is the distance between the ultrasonic transducer 14 and the reflector 15. τ ₀ and L ₀ are initially set by the τ ₀ setting unit 25 and the L ₀ setting unit 26.

The temperature data (T) of the solution 1 to be measured detected by the temperature detector 16 is stored in the RAM 24 through the temperature measurement unit 19, the A / D conversion unit 27, and the input / output unit 21. The conductivity data (σ) of the solution 1 to be measured detected by the conductivity detector 17 is stored in the RAM 24 via the conductivity measuring unit 20, the A / D conversion unit 28, and the input / output unit 21.
The ROM 23 of the arithmetic unit 11 constitutes a storage unit of the present invention, and includes the temperature (T) of the solution 1 to be measured, the specific physical property amount (α ₁ ... Α _n-1 ) and the ultrasonic wave propagation velocity (V). A function (1) expression indicating the relationship with the concentration (D ₁ ... D _n ) of each solute is stored.
For example, the solution 1 to be measured is obtained by dissolving two solutes NaOH and NaCl as described above, and when the electrical conductivity σ is selected as the specific physical property amount, the NaOH concentration D ₁ and the NaCl concentration D _{2 are selected.} Is as follows.
V = F ₁₁ (T, D ₁ , σ) (2)
V = F ₁₂ (T, D ₂ , σ) (3)
σ = F ₂₁ (T, D ₁ , V) (4)
σ = F ₂₂ (T, D ₂ , V) (5)
The above function can be expressed by a multi-order polynomial, and up to what order the multi-order polynomial is used is determined by the required accuracy of concentration measurement.

Using the equation of the solution, two solutions are obtained from the above equation (2), which are respectively set as D ₁₁ and D _12, and similarly to the equation (2), D ₁ is calculated in the equation (4) as D ₁₁ and D _12. Then, the conductivity σ is calculated by substituting the temperature T and the speed of sound V, and the value used to calculate a value close to the measured conductivity σ value among D ₁₁ and D ₁₂ is defined as D _1A .
In the above equations (3), (4), and (5), D ₁ and D ₂ are similarly obtained, and D ₁ obtained from equation (4) is obtained from D _1B and equation (3). Let D ₂ be D _2A and D ₂ obtained from the equation (5) be D _2B .
Strictly speaking, Equations (2) and (4), and Equations (3) and (5) should draw exactly the same curve, but changes occur due to measurement errors, etc., and the resulting concentration D ₁ also changes. Therefore, in order to measure the concentration with high accuracy, it is necessary to select the values of D ₁ and D ₂ as _one by the following method. For this, in the graph normalized by the maximum value and the minimum value of the sound velocity and the conductivity, the slope of the tangent at the calculated concentration obtained by each formula is used.
Since the sound velocity value and the conductivity value have different units and numerical values, they are standardized as 0-1 or 0-100.
For example, the following variations in the case of concentration D ₁ (2) expression.
V = F ₁₁ (T, D ₁ , σ) = (f ₁ (T, σ)) D ₁ ² + (f ₂ (T, σ)) D ₁ + (f ₃ (T, σ))... (6)
For simplicity, if x _1A = f ₁ (T, σ) y _1A = f ₂ (T, σ) z _1A = f ₃ (T, σ)
V = x _{1 A} D ₁ ² + y _{1 A} D ₁ + z _1A (7)
And this one-time derivative is
V ′ = 2x _1A D ₁ + y _1A (8)
Where D _1A is substituted into equation (8), and the ordinate represents sound velocity (V) and the horizontal axis represents density (D ₁ ), the tangential slope J _1A is obtained, and equation (4) is also obtained. Similarly deformed,
σ = F ₂₁ (T, D ₁ , V) = (f ₁ (T, V)) D ₁ ² + (f ₂ (T, V)) D ₁ + (f ₃ (T, V))... (9)
For simplicity, if x _1B = f ₁ (T, V) y _1B = f ₂ (T, V) z _1B = f ₃ (T, V)
σ = x _1B D ₁ ² + y _1B D ₁ + z _1B (10)
And this one-time derivative is
σ ′ = 2x _1B D ₁ + y _1B (11)
Here, when D _1B is substituted into the equation (11), the tangential slope J _1B is obtained when the conductivity (σ) is plotted on the vertical axis and the concentration (D ₁ ) is plotted on the horizontal axis.

5A shows an example of a tangent line derived from the expression (2), and FIG. 5B shows an example of a tangent line derived from the expression (4).
6A shows the amount of change in density (D ₁ ) when the sound velocity (V) in FIG. 5A changes by a certain amount, and FIG. 6B shows the conductivity ( The amount of change in density (D ₁ ) when σ) changes by a certain amount is shown.
Here, comparing the amount of change in the density (D ₁ ) due to the slope of the tangent, it can be seen that the amount of change in the density (D ₁ ) when the sound speed (V) changes by a certain amount is smaller.

Next, using the equation of the solution, when formulas (7) and (10) are made into the form of “D ₁ =”,
From equation (7)
_{D 1 = (- y 1A ±} (y 1A 2 -4x 1A (z 1A -V)) 1/2) / 2x 1A
= (− F ₂ (T, σ) ± (f ₂ (T, σ) ² −4f ₁ (T, σ) (f ₃ (T, σ) −V)) ^1/2 ) / 2f ₁ (T, σ) (12)
From equation (10)
D ₁ = (− y _1B ± (y _1B ² −4x _1B (z _1B −σ)) ^1/2 ) / 2x _1B
= (-F ₂ (T, V) ± (f ₂ (T, V) ² -4f ₁ (T, V) (f ₃ (T, V) -σ)) ^1/2 ) / 2f ₁ (T, V) ・ ・ ・ (13)
From the equation (12), the equation (7), that is, the equation (2) has a great influence on the concentration (D ₁ ) by the conductivity (σ). From the equation (13), the equation (10), that is, the equation (4) expression, since the sound speed (V) becomes larger influence on the density (D _1), than the comparison of the variation of the concentration (D ₁₎ by the gradient of the tangent of the aforementioned acoustic velocity (V) is the concentration (D ₁₎ The density having the larger influence, that is, D _1B obtained from the equation (4) is defined as the density (D ₁ ). Similarly, the concentration (D ₂ ) can be detected.

The constants of the multi-degree polynomial are determined as follows. For example, in a solution containing two components of NaOH and NaCl as a solute, a combination of NaOH concentration (D ₁ ) 2.00 to 4.00%, NaCl concentration (D ₂ ) 10.00 to 14.00%, and temperature (T) 45 to 60 ° C. As shown in Table 1, the propagation velocity (V) and conductivity (σ) in the solution are measured.
The measurement of the temperature (T), speed (V), and conductivity (σ) can be performed using the measuring apparatus 10 of the present invention, as will be described later. At least 27 combinations of D ₁ , D ₂ , T, V, and σ shown in Table 1 are prepared, and the data of each set is substituted into the equations (2), (3), (4), and (5). Thus, each constant can be determined as shown in Table 2 by solving simultaneous equations with the constants as unknowns.

This constant C (i) is stored in the ROM 23 of the arithmetic unit 11 by the ROM writer. The ROM writer calculates and verifies each constant C (i) from each D ₁ , D ₂ , T, V, σ (D ₁ , D ₂ , T, V not used for calculating C (i) above). , σ), and stored in the ROM 23 only when each C (i) is appropriate.
Therefore, the CPU 22 as the concentration calculation unit of the present invention calculates the concentration of the solution in which a plurality of (n) solutes (for example, NaOH, NaCl) are dissolved as follows. That is, the CPU 22 transmits the ultrasonic wave propagation velocity (V) calculated based on the detection amount of the ultrasonic transducer 14, the temperature (T) detected by the temperature detector 16, the data detected by the specific physical property detector, For example, by substituting each of the conductivity (σ) into the above-described equations (2), (3), (4), (5), the concentration of each solute (D ₁ ... D _n ), for example, the concentration D of NaOH calculating a ₁ and the density D ₂ of NaCl.
The arithmetic device 11 includes a function setting unit 29. The function setting unit 29 sets the operation of the arithmetic unit 11.
(A) a mode in which only the ultrasonic propagation velocity (V) is measured and displayed;
(B) Mode for measuring and displaying only temperature (T),
(C) a specific physical property amount (α ₁ ... Α _n-1 ), for example, a mode for measuring and displaying only the conductivity (σ),
(D) A mode for calculating and displaying the density (D ₁ , D ₂ ) is set.

  The measurement result and calculation result obtained by the setting of the function setting unit 29 are displayed on the display unit 13 or taken out from the output unit 30 as an analog output. The display 13 and the output unit 30 constitute an output device of the present invention, and these outputs can be used as a solution to be measured and other control information.

Hereinafter, a procedure for measuring the concentration of an aqueous solution containing two components of NaOH and NaCl as a solute by the concentration measuring apparatus 10 will be described (see FIG. 4).
The above-described τ ₀ and L ₀ are set by the τ ₀ setting unit 25 and the L ₀ setting unit 26 of the arithmetic unit 11, and the function setting unit 29 is set to any measurement / calculation mode.
(A) In the sound velocity calculation mode, the sound velocity processing subroutine is operated, and the ultrasonic wave propagation velocity (V) in the solution 1 to be measured is calculated and output as described above.
(B) In the temperature measurement mode, the temperature processing subroutine is operated, and the temperature (T) of the solution 1 to be measured is calculated and output as described above.
(C) In the conductivity measurement mode, the conductivity processing subroutine operates, and the conductivity (σ) of the solution 1 to be measured is measured and output as described above.
(D) In the concentration calculation mode, the data obtained in the subroutines (a) to (c) above are used, and the NaOH concentration D ₁ and the NaCl concentration are calculated from the functions stored in the ROM 23 as described above. concentration D ₂ is calculated and output.
(The calculated values are shown in Table 3.)
The above-mentioned concentration measuring apparatus for various concentrations of the solutions having several kinds of concentrations D ₁ and D ₂ already known for the aqueous solution containing the above two components of NaOH and NaCl (analyzed values in Table 3). Table 3 shows D ₁ and D ₂ measured at 10 together with ultrasonic propagation velocity (V) and conductivity (σ). According to Table 3, it can be seen that the present invention can perform a measurement in which the analytical value and the calculated value are very approximate.

Table 4 shows the concentration measurement results of a developing solution containing TMAH / RESIST / CO ₃ as a solute used in the FPD development process as an example of an aqueous solution containing three components as a solute. Here, the temperature (T) of the solution, the propagation velocity (V) of the ultrasonic wave, the conductivity (σ) and the absorbance (Abs) are used, and the concentration D _{1 of} TMAH, the concentration D _{2 of} RESIST, and CO 2 ₃ concentration _{D 3,} are measured.
The specific physical properties used in the practice of the present invention are not limited to conductivity and absorbance, but include density, PH, light refractive index, radiation attenuation rate, ultrasonic frequency used, and third value for the solution to be measured. Wide range of solute additions. For example, in a multi-component solution in which n = 3 types of solutes are dissolved in a solvent, n−1 = 2 types of specific physical properties that are influenced independently of the propagation velocity (V) are used. Therefore, for example, if the electrical conductivity (σ) and the density (ρ) are selected as specific physical property amounts, the concentrations D ₁ , D ₂ , D ₃ of each solute are calculated by the following functions.
V = F ₁₁ (T, D ₁ , σ, ρ) (14)
V = F ₁₂ (T, D ₂ , σ, ρ) (15)
V = F ₁₃ (T, D ₃ , σ, ρ) (16)
σ = F ₂₁ (T, D ₁ , V, ρ) (17)
σ = F ₂₂ (T, D ₂ , V, ρ) (18)
σ = F ₂₃ (T, D ₃ , V, ρ) (19)
ρ = F ₃₁ (T, D ₁ , V, σ) (20)
ρ = F ₃₂ (T, D ₂ , V, σ) (21)
ρ = F ₃₃ (T, D ₃ , V, σ) (22)
That is, according to the present invention, since the concentration of the solution to be measured can be output in real time and high accuracy is obtained, it is useful for measuring the concentration of various multi-component solutions, and widely used in industrial processes such as chemicals and foods. Applicable.

As an example, the concentration was measured for the following 15 types of solutions.
· CMP slurries + additives + H ₂ Simultaneous measurement of additive concentration and CMP slurry of O · SC-1 (ammonia + H ₂ O ₂ + H ₂ O) of ammonia in a concentration of H ₂ O ₂ Simultaneous measurement · SC-2 of (HCl + H ₂ O ₂ + H ₂ O) in HCl and concentration of H ₂ O ₂ simultaneous measurement · TMAH + resist + H ₂ simultaneous measurement of TMAH and resist concentration in O · HF + H ₂ SiF ₆ + H ₂ simultaneous HF and H ₂ SiF ₆ concentration in O of Measurement • Simultaneous measurement of TMAH, resist and carbonate concentrations in TMAH + resist + carbonate + H ₂ O • Simultaneous measurement of HF and H ₂ O ₂ concentrations in FPM (HF + H ₂ O ₂ + H ₂ O) • H ₂ SO ₄ + Cu + H ₂ Simultaneous measurement of H ₂ SO ₄ and Cu concentration in O • Simultaneous measurement of HF and HNO ₃ concentration in HF + HNO ₃ + H ₂ O • H ₂ SO ₄ and H ₂ O ₂ concentration in H ₂ SO ₄ + H ₂ O ₂ + H ₂ O・ Simultaneous measurement of NH ₄ F and HF concentration in BHF (NH ₄ F + HF + H ₂ O) ・ Simultaneous measurement of H ₃ PO ₄ and HNO ₃ concentration in H ₃ PO ₄ + HNO ₃ + H ₂ O ・ KOH + H Simultaneous measurement of KOH and H ₂ O ₂ concentrations in ₂ O ₂ + H ₂ O • Simultaneous measurement of HCl and FeCl ₃ concentrations in HCl + FeCl ₃ + H ₂ O • Simultaneous measurement of HF and HCl concentrations in HF + HCl + H ₂ O

The ultrasonic concentration calculation method and the ultrasonic concentration measuring apparatus of the present invention can be applied to the concentration measurement of the following solutions and the like.
· Stripping solution + resist + simultaneous measurement of NaCl and NaClO concentrations in simultaneous measurement-NaCl + NaClO + H ₂ O of NaOH and NaClO concentrations in simultaneous measurement-NaOH + NaClO + H ₂ O stripper and resist concentration in pure water _{· H 3 PO 4 + HNO 3} + CH 3 Simultaneous measurement of H ₃ PO ₄ , HNO ₃ and CH ₃ COOH ₄ concentrations in COOH ₄ + H ₂ O ・ Simultaneous measurement of HF, HNO ₃ and H ₂ SiF ₆ concentrations in HF + HNO ₃ + H ₂ SiF ₆ + H ₂ O ・ Various plating solutions

1 is a block diagram showing an ultrasonic concentration measuring apparatus according to an embodiment of the present invention. (A) is a front view showing a sensor used in the practice of the present invention, (B) is a sectional view taken along line BB in FIG. 2 (A), and (C) is a line CC in FIG. 2 (A). Sectional view along Waveform diagram showing the state of ultrasonic transmission / reception Flow chart showing operation of ultrasonic concentration measuring device (A) shows an example of a tangent derived from the equation (2), and (B) shows an example of a tangent derived from the equation (4). (A) shows the shift amount of density (D ₁ ) when the sound velocity (V) in FIG. 5 (A) shifts by a certain amount, and (B) shows the constant conductivity (σ) in FIG. 5 (B). The deviation amount of the density (D ₁ ) when the amount is displaced is shown.

Explanation of symbols

10 ... Ultrasonic concentration measuring device
11 ... arithmetic unit
12 ... Sensor
13 ... Display
14 ... Ultrasonic transducer
15 ... Reflector
16 ... Temperature detector
17 ... Conductivity detector
18 ... Sing around part
19 ... Temperature measurement unit
20 ... Conductivity measurement unit
21 ... Input / output section
22 ... CPU (speed calculator, concentration calculator)
23 ... ROM (memory)
24 ... RAM
25… τ ₀ setting part
26 ... L ₀ setting section
27 ... A / D converter
28 ... A / D converter
29 ... Sw
30 ... Output section

Claims (2)

An ultrasonic concentration measurement method for measuring each concentration (D ₁ ... D _n ) of a plurality of (n) solutes dissolved in a solvent, which transmits ultrasonic waves to a solution to be measured and propagates through the solution to be measured. The ultrasonic wave is received, the propagation speed (V) is calculated from the propagation time and propagation distance of the ultrasonic wave, the temperature (T) of the solution to be measured is detected, and the above is determined depending on the concentration of each solute and the temperature of the solution to be measured. (N-1) types of specific physical properties (α ₁ ... α _n-1 ) that are independently affected by the propagation speed, and are affected independently by the concentration of each solute and the temperature of the solution to be measured. A function V = representing the relationship among (n-1) kinds of specific physical properties (α ₁ ... α _n-1 ), ultrasonic wave propagation speed (V), and solute concentrations (D ₁ ... D _n ). F ₁₁ (T, D ₁ , α ₁ ... Α _n-1 )... V = F _1n (T, D _n , α ₁ ... Α _n-1 )
α ₁ = F ₂₁ (T, D ₁ , V, α ₂ ... α _n-1 )... α ₁ = F _2n (T, D _n , V, α ₂ … α _n-1 )
_{α 2 = F 31 (T,} D 1, V, α 1, α 3 ... α n-1) ··· α 2 = F 3n (T, D n, V, α 1, α 3 ... α n-1 )
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α _n-1 = F _n1 (T, D ₁ , V, α ₁ ... α _n-2 )... α _n-1 = F _nn (T, D _n , V, α ₁ ... α _n-2 )
, Concentration of each solute (D ₁ ... D _n ) based on the function from the temperature (T), the specific physical property amount (α ₁ ... Α _n−1 ), and the propagation velocity (V). Method. An ultrasonic concentration measuring device for measuring each concentration (D ₁ ... D _n ) of a plurality of (n) solutes dissolved in a solvent, an ultrasonic transmitter for transmitting ultrasonic waves to a solution to be measured; An ultrasonic receiver for receiving the ultrasonic wave propagated in the liquid to be measured, a velocity calculating unit for calculating the propagation velocity (V) from the propagation time and propagation distance of the ultrasonic wave, and the temperature (T) of the solution to be measured (N-1) types of specific physical properties (α ₁ ... α _n-1 ) that are independently affected by the propagation speed depending on the concentration of each solute and the temperature of the solution to be measured. There are (n-1) kinds of specific physical properties (α ₁ ... Α _n-1 ) that are independently influenced by the concentration of each solute and the temperature of the solution to be measured, and the ultrasonic wave propagation velocity (V) , V = F ₁₁ (T, D ₁ , α ₁ ... α _n-1 )... V = F _1n (T, D _n , α) showing the relationship with the concentration (D ₁ ... D _n ) of each solute. ₁ … α _n-1 )
α ₁ = F ₂₁ (T, D ₁ , V, α ₂ ... α _n-1 )... α ₁ = F _2n (T, D _n , V, α ₂ … α _n-1 )
_{α 2 = F 31 (T,} D 1, V, α 1, α 3 ... α n-1) ··· α 2 = F 3n (T, D n, V, α 1, α 3 ... α n-1 )
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α _n-1 = F _n1 (T, D ₁ , V, α ₁ ... α _n-2 )... α _n-1 = F _nn (T, D _n , V, α ₁ ... α _n-2 )
From the storage unit, the output (T) of the temperature detector, the output (α ₁ ... Α _n-1 ) of the specific physical property detector, and the output (V) of the speed calculation unit, An ultrasonic concentration measurement apparatus comprising: a concentration calculation unit that calculates a concentration (D ₁ ... D _n ) of each solute based on a function; and an output device that outputs a calculation result of the concentration calculation unit.

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