JP2000258362A - Microwave type densitometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure the concentration change in such mixed substance as the solid content of target liquid containing bubbles by measuring the concentration of the liquid to be measured in a plurality of different pressure states and correcting the influence of bubbles using the plurality of measurement values. SOLUTION: An automatic gate valve 22 is opened by the control signal of a controller 33, a pressure-reducing mechanism 31 is operated, a switching valve 32 is set to the side of the pressure-reducing mechanism 31, a piston 24 is withdrawn from a delivery position, liquid to be measured flowing to detector piping 21 is sampled into a measurement chamber cylinder 23, and the automatic gate valve 22 is closed. A pressurization pressure source 30 is operated, the switching valve 32 is switched to the side of the pressurization pressure source 30, a piston 24 is pressed down, the inside of the measurement chamber cylinder 23 is gradually pressurized and at the same time pressure is measured by a pressure detector 26, and the signal is inputted to the controller 33. On the other hand, a phase measurement system according to microwaves is operated, pressurization is made and at the same time a phase is measured, concentration is obtained using a calibration curve by a concentration computing element 34, the influence of bubbles is corrected by a bubble influence correction computing element 35, and the concentration of the solid content of liquid to be measured is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, sewage sludge,
The present invention relates to a microwave type densitometer for measuring the concentration of a mixed substance such as a solid content in a liquid to be measured including a mixed substance such as various suspended substances and soluble substances such as pulp and paint. It relates to a microwave-type densitometer that corrects the influence of air bubbles even when a large amount of air bubbles are contained in it, thereby realizing accurate concentration measurement of mixed substances such as solids in the liquid to be measured. is there.

[0002]

2. Description of the Related Art Conventionally, as an instrument for measuring the concentration of a suspended substance or the like in a liquid, an ultrasonic densitometer that measures the attenuation rate of an ultrasonic wave to obtain a concentration, a transmission light attenuation rate using light, Optical densitometers that measure the scattered light increase rate to determine the concentration have been widely used.

[0003] However, in the former ultrasonic type densitometer, when air bubbles are mixed in the fluid, it is greatly affected by the air bubbles and the measurement error increases.

In the latter optical densitometer, if dirt adheres to an optical window through which light enters or receives light, the dirt is greatly affected by the contamination and measurement errors increase.

Therefore, recently, a microwave densitometer has been developed as a densitometer which is hardly affected by bubbles and dirt.
It is being put to practical use.

FIG. 5 is a schematic diagram showing an example of a basic configuration of this type of conventional microwave densitometer.

[0007] As shown in FIG.
In addition, a microwave transmitting antenna 11 and a microwave receiving antenna 12 are arranged to face each other, and a microwave is supplied from a microwave oscillator 13.

As a microwave passage, a first path introduced into the phase measuring circuit 15 through the power splitter 14 to the microwave transmitting antenna 11 to the liquid in the tube to the microwave receiving antenna 12 is the same as the microwave. Is formed through the power splitter 14 and into the phase measurement circuit 15.

Then, the phase difference measuring circuit 15 determines the phase difference from the phase delay of the microwave from the first path with respect to the microwave from the second path.

In this densitometer, the phase delay θ2 of the microwave propagating in the liquid to be measured in the pipe with respect to the microwave directly received from the microwave oscillator 13 via the power splitter 14 and the reference Fluid (for example,
A comparison is made between the phase delay θ1 of the microwave when the sample is filled with tap water (which can be regarded as having a concentration of zero) and measured under the same conditions as the liquid to be measured, and the phase difference Δθ = (θ2−θ1), as shown in FIG. The concentration of the liquid to be measured is determined using a simple calibration curve.

That is, specifically, the density X = aΔθ +
The density is obtained by performing the calculation of b.

Note that a is the slope of the calibration curve, b is the intercept of the calibration curve, and b = 0 normally.

The above-mentioned microwave densitometer is not a method for measuring the attenuation rate of microwaves, but a method for measuring a phase difference, and a window for receiving or receiving microwaves is transparent. Since it is not necessary, it is hardly affected by bubbles and dirt, and the concentration can be continuously measured.

[0014]

As described above, the microwave densitometer is a measurement method which is less susceptible to bubbles as compared with an ultrasonic densitometer or the like. If a large amount of air bubbles are contained, the effect cannot be ignored.

Here, a large amount of bubbles is a vague expression, but as a guide, the bubble content is such that even if the temperature is 20 ° C. and the pressure is increased to about 0.5 MPa, the bubble content is 20%.
It is defined that about 9% or more in terms of volume% at ° C is a large amount of bubbles. As an example of the liquid to be measured having a large content of bubbles, there is a coating liquid of about 30% by volume.

When a large amount of air bubbles are contained, the value measured by the microwave densitometer shows a higher value than when no air bubbles are contained, and the measured value is substantially proportional to the bubble content. Going higher.

Therefore, when the measured value changes, it is not known whether the concentration of the mixed substance, such as solid content, which should be measured, has changed, or the measured value has changed due to a change in the content of bubbles. Needs to be corrected.

However, conventionally, there is no good method for detecting a change in the amount of air bubbles, and a concentration capable of accurately measuring the change in the concentration of a mixed substance such as a solid content by correcting the influence of air bubbles. A measure is strongly desired.

An object of the present invention is to correct the influence of air bubbles on a measured value even when a large amount of air bubbles is contained in a liquid to be measured, and to adjust the concentration of a mixed substance such as a solid content in the liquid to be measured. It is an object of the present invention to provide a microwave densitometer capable of performing accurate measurement.

[0020]

In order to achieve the above object, according to the first aspect of the present invention, a microwave transmitting antenna and a microwave receiving antenna are arranged opposite to each other so as to sandwich a liquid to be measured. , A microwave is incident on a reference liquid, propagates through the reference fluid, and is received by a microwave receiving antenna.
1 is measured and stored in a memory, and a microwave is incident on a liquid to be measured from a microwave transmitting antenna, propagates through the liquid to be measured, and receives a phase delay of the microwave received by the microwave receiving antenna. By measuring θ2, the phase difference of each phase delay Δθ = (θ2−θ1) is calculated, and the concentration X of the liquid to be measured is measured based on the calibration curve X = aΔθ + b corresponding to each type of the liquid to be measured. In a microwave type densitometer, the concentration of the liquid to be measured is measured at a plurality of pressure states different from each other, and the influence of air bubbles is corrected using a plurality of measured values obtained by the measurement, so that the concentration in the liquid to be measured is The concentration of a mixed substance such as solid content is determined.

Therefore, in the microwave type densitometer according to the first aspect of the present invention, the concentration of the liquid to be measured is measured at a plurality of different pressure states, and a plurality of measured values obtained by the measurement are used to measure the bubble. When applying to a measurement target liquid containing a large amount of air bubbles by correcting the effect, it is necessary to correct the effect of air bubbles on the measurement value and accurately measure the change in the concentration of a mixed substance such as solid content. it can.

According to the second aspect of the present invention, the first aspect is provided.
In the microwave type densitometer of the invention, the concentration of the liquid to be measured is measured by setting a plurality of different pressure states to three or more kinds of pressures, and the measured value in the lowest pressure state and the measurement in another pressure state are measured. The correction values for the influence of bubbles calculated from the values are averaged to obtain the concentration of a mixed substance such as a solid content in the liquid to be measured.

Therefore, in the microwave type densitometer according to the second aspect of the present invention, the liquid to be measured is measured by setting a plurality of different pressure states to three or more kinds of pressures, and the measured value in the lowest pressure state by this measurement is measured. By averaging the correction values for the influence of the air bubbles calculated from the measured values in the other pressure states, it is possible to perform the correction with higher accuracy than in the case of the first aspect of the present invention. .

According to a third aspect of the present invention, in the microwave concentration meter according to the first aspect of the present invention, the concentration of the liquid to be measured is continuously measured while increasing the pressurizing pressure with the passage of time. When the differential value of the measured value falls below a predetermined value, a means for outputting the measured value at that time as a concentration measured value of a mixed substance such as a solid content not affected by bubbles is added. ing.

Therefore, in the microwave densitometer according to the third aspect of the present invention, the concentration of the liquid to be measured is continuously measured while increasing the pressurizing pressure with the passage of time, and the derivative of the measured value is differentiated. The method according to claim 1, wherein when the value becomes equal to or less than a predetermined value, the measured value at that time is adopted as a concentration measured value of a mixed substance such as a solid content not affected by bubbles. The invention of the second aspect is applied to a case where a large amount of air bubbles is contained so as not to cause a large error even if the amount of air bubbles newly melted by pressurization is omitted in the calculation, whereas the air bubbles are newly melted by pressurization. This can be applied to the case where the bubble content is such that the bubble amount cannot be omitted.

In the above description, for example,
As described in above, it is preferable that one of a plurality of different pressure states be atmospheric pressure (about 0.1 MPa).

Also, for example, as described in claim 5,
It is preferable that a measurement chamber is provided on the side of the pipe through which the liquid to be measured flows, and a part of the liquid to be measured is collected in the measurement chamber, sealed, and then pressurized.

Further, it is preferable that the measuring chamber is formed in a cylindrical shape and the measuring chamber is pressurized by a piston sliding inside the measuring chamber.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method for measuring the concentration of a mixed substance such as a solid content in a liquid to be measured containing a mixed substance such as various suspended substances and soluble substances such as sewage sludge, pulp and paint. In a microwave type densitometer for measuring, in particular, in the conventional measurement liquid containing a large amount of bubbles, accurate concentration measurement could not be performed due to the influence of the bubbles, but a plurality of pressure states different from each other (for example, atmospheric pressure). State and the state where the pressure is higher than that), by correcting the effect of the bubble on the concentration measurement value based on the measured value, even if a large amount of bubble is contained in the liquid to be measured, Is corrected so that the change in the concentration of a mixed substance such as a solid content in the liquid to be measured can be accurately measured.

First, a method of correcting the influence of bubbles which is a premise of the present invention will be described with reference to FIG.

As shown in FIG.
1 MPa (atmospheric pressure), 0.5 MPa as a high pressure state,
The method of measuring under each pressure state will be described as an example.

The bubble content (volume%) at t ° C. and 0.1 MPa is defined as (V1 / (1 + V1)).

That is, it is assumed that there is a bubble portion V1 (L) with respect to the portion 1 (L) of the liquid to be measured which does not contain bubbles.

Here, L means liter. Also,
The lowercase "l" is easy to mistake as 1, so the uppercase "L"
Is used.

V10 = (273 / (273 + t)) · V1 The value of V1 converted to 0 ° C. and 0.1 MPa is V10 = (273 / (273 + t)) · V1 Bubbles contained when the liquid to be measured containing these bubbles is pressurized to 0.5 MPa. Let the rate be (V5 / (1 + V5)).

That is, there is a bubble portion V5 (L) with respect to the portion 1 (L) of the liquid to be measured which does not contain bubbles.

[Physical Law] The volume of gas dissolved in water at t ° C. is determined for each gas.
The volume at (L) converted to a state of 0.1 ° C. and 0.1 MPa is referred to as an absorption coefficient. For example, air is 0.018 in 20 ° C. water.
Dissolve 2 (L). That is, at = 0.0182. Further, the dissolved amount of the gas is proportional to the pressure. Further, the volume of the gas is inversely proportional to the pressure. According to the above-mentioned laws of physics, the above-mentioned V5 at 0 ° C. and 0.1 MPa equivalent volume V50
V50 = (V10 + at) -5at = V10-4at = (273 / (273 + t)) · V1-4at where + at is a bubble dissolved in the liquid in a state of 0.1 MPa. The amount, 1 at, is the amount of bubbles dissolved in the liquid at 0.5 MPa.

Therefore, when V5 is represented using V1, V5 = (V50 / 5). ((273 + t) / 273) = {((273 / (273 + t)). V1-4at) /
5｝ · ((273 + t) / 273) = (V1 / 5) one (4at / 5) · ((273 + t) /
273) Assuming that the measured value of the microwave densitometer at the pressure of 0.1 MPa is Y1 and the measured value of the microwave densitometer at the pressure of 0.5 MPa is Y5, Y1 = CX + kV1 (1) Y5 = CX + kV5 (2) Here, CX is a value proportional to the concentration X of the solid content in the liquid to be measured, kV1 and kV5 are values originally intended to be measured, and kV1 and kV5 are values appearing as the influence of bubbles, and are proportional to the bubble content. .

From the above equations (1) and (2), Y1−Y5 = kV1−kV5 = kV1−k ｛(V1 / 5) (4at / 5) · ((2
73 + t) / 273)｝ = 0.8 kV1 + k (4 at / 5) · ((273 + t)
/ 273) The second term on the right-hand side of the above equation is the influence of bubbles dissolved in the liquid by pressurizing to 0.5 MPa.
When 1 is large, since it is small compared to the first term, even if it is omitted, no large error occurs.

For example, when air bubbles are air at 20 ° C.,
Since at = 0.0182, Y1−Y5 = 0.8 kV1 + k ((4 × 0.0182)
/5)·((273+20)/273)=0.8 kV1 + 0.0156k If V1 is large and the second term is omitted, then Y1-Y5 = 0.8 kV1 kV1 = (Y1-Y5) /0.8. Substituting into the above equation (1), Y1 = CX + (Y1-Y5) /0.8 CX = (Y5-0.2Y1) /0.8 The value CX proportional to the concentration X of the solid content to be measured is calculated as the measured value Y1
And Y5.

In the above example, the high pressure state is set to 0.5
However, in the case of 0.4 MPa, kV1 = (Y1-Y4) / (3/4), and in the case of 0.3 MPa, kV1 = (Y1-Y3) / (2/3). In the same manner as in the case of 0.5 MPa, the influence of air bubbles can be corrected.

Hereinafter, embodiments of the present invention based on the above concept will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a schematic diagram showing a configuration example of a microwave type densitometer according to the present embodiment, and the same elements as those in FIG. I have.

In FIG. 1, the liquid to be measured flows through the detector pipe 21.

A measuring chamber cylinder 23 formed in a cylindrical shape is attached to a side surface of the detector pipe 21.

An automatic gate valve 22 is provided between the detector pipe 21 and the measuring chamber cylinder 23.

On the other hand, the piston 24 presses the measurement chamber cylinder 23 by sliding in the measurement chamber cylinder 23 while maintaining airtightness through the sealing material 25.

The pressure detector 26 measures the pressure in the measurement chamber cylinder 23.

The piston position detectors 27, 28, 29
The sampling end position, pressurization position, and discharge position of the piston 24 are detected, respectively.

The pressurizing pressure source (compressor or the like) 30 presses down the piston 24 in the measuring chamber cylinder 23 to pressurize it, and is connected to the measuring chamber cylinder 23 via a switching valve 32 by air piping.

Decompression mechanism (vacuum pump, aspirator, etc.)
Reference numeral 31 denotes a device for depressurizing the inside of the measurement chamber cylinder 23 at the time of sampling and drawing in the piston 24, and is connected to the measurement chamber cylinder 23 via a switching valve 32.

On the other hand, 11, 12, 13, 14, 15
Similar to the microwave type densitometer of FIG. 5, a microwave transmitting antenna, a microwave receiving antenna, a microwave oscillator, a power splitter, and a phase difference measuring circuit are mounted on the measuring chamber cylinder 23, respectively.

The controller 33 controls the operation sequence of the densitometer, and receives output signals from the pressure detector 26 and the piston position detectors 27, 28 and 29,
Control signals are supplied to the automatic gate valve 22, the pressurizing pressure source 30, the pressure reducing mechanism 31, the switching valve 32, the phase measuring circuit 15, and the bubble influence correction calculator 35.

The density calculator 34 receives the output signal from the phase measuring circuit 15 and performs a density calculation based on the above-mentioned calibration curve.

The bubble effect correction calculator 35 is a density calculator 3
4 and receiving the output signal from the controller 33,
The concentration of the mixed substance such as the solid content of the liquid to be measured is calculated by correcting the influence of the bubbles, and is output.

Next, the operation of the microwave type densitometer of the present embodiment configured as described above will be described with reference to the state diagram shown in FIG.

(A) Sampling step (FIG. 2A,
(Refer to (b).) Based on a control signal from the controller 33, the automatic gate valve 22 is opened, the pressure reducing mechanism 31 is operated, and the switching valve 32 is operated.
The pressure is also switched to the pressure reducing mechanism 31 side, the piston 24 is retracted from the discharge position, the liquid to be measured flowing through the detector pipe 21 is collected in the measuring chamber cylinder 23, and then the automatic gate valve 22 is closed.

(B) Pressurizing / measuring step (see FIG. 2C) The pressurizing pressure source 30 is operated based on a control signal from the controller 33, and the switching valve 32 is also moved to the pressurizing pressure source 30 side. Switch and push down the piston 24 to move the measurement chamber cylinder 2
The liquid to be measured containing bubbles collected in 3 is gradually pressurized. Then, while applying pressure, the pressure P in the measurement chamber cylinder 23 measured by the pressure detector 26 is measured, and the signal is input to the controller 33.

On the other hand, the phase measurement system using microwaves is also operated, and the phase is measured while applying pressure to obtain the measured value Y shown in FIG.

That is, the microwave is supplied from the microwave oscillator 13 to the microwave transmitting antenna 11 attached to the measuring chamber cylinder 23 via the power splitter 14, and the microwave receiving antenna arranged opposite to the microwave transmitting antenna 11 is supplied. There is a first path through which the antenna 12 receives the microwave signal transmitted through the liquid to be measured in the measurement chamber cylinder 23 and sends the signal to the phase difference measurement circuit 15.

The microwave from the microwave oscillator 13 has a second path which is directly sent to the phase difference measuring circuit 15 via the power splitter 14.

Then, the phase difference measuring circuit 15 determines the phase delay of the microwave from the first path with respect to the microwave from the second path.

In the concentration calculator 34, the measuring chamber cylinder 23
The phase delay θ2 of the microwave propagating in the liquid to be measured and the reference fluid (for example, tap water which can be regarded as having a concentration of zero) are previously filled in the measuring chamber cylinder 23 and measured under the same conditions as the liquid to be measured. Compared with the phase delay θ1 of the microwave at this time, the density difference is calculated using the calibration curve as shown in FIG. 6 from the phase difference Δθ = (θ2−θ1) to obtain the measured value Y shown in FIG.

The bubble effect correction calculator 35 corrects the influence of bubbles based on the measured values Y from the concentration calculator 34 at a plurality of predetermined pressures, and calculates the concentration of the solid content of the liquid to be measured. Is output.

For example, pressures of 0.1 MPa and 0.3 MPa
Assuming that the measurement is performed at three pressure states of 0.5 MPa and 0.5 MPa, the influence amount kV1 of the bubble is obtained from the following equation from the measured values Y1, Y3, and Y5 at the respective pressures.

KV1 = (Y1-Y3) / (2/3) kV1 = (Y1-Y5) /0.8 Furthermore, the average value of these values kV1 = ｛((Y1-Y3) / (2/3) ) + ((Y1
−Y5) /0.8)｝ / 2, and this value is subtracted from the value of Y1 as the influence of air bubbles, and the CX corresponding to the concentration of the mixed substance such as the solid content of the liquid to be measured is calculated. Output as the concentration of the mixed substance such as minute.

(C) Sample discharging step (see FIG. 2D) After the pressurizing / measuring step, the automatic gate valve 22 is opened based on the control signal from the controller 33, and the pressurizing pressure source 3
0, the switching valve 32 is also switched to the pressurizing pressure source 30 side, and the piston 24 in the measuring chamber cylinder 23 is pushed down to the discharge position, and the liquid to be measured in the measuring chamber cylinder 23 is Is discharged into the flow of the liquid to be measured. In that state, it waits until the next sampling step.

As described above, in the microwave type densitometer of the present embodiment, the concentration of the liquid to be measured is measured under a plurality of different pressure states, and the bubble is measured using the plurality of measured values obtained by the measurement. When applying to a measurement target liquid containing a large amount of air bubbles, the effect of air bubbles on the measured value is corrected, and the change in the concentration of a mixed substance such as solid content can be accurately corrected. It becomes possible to measure.

The liquid to be measured is measured by setting a plurality of different pressure states to three or more kinds of pressures, and the bubble calculated from the measured value in the lowest pressure state and the measured value in another pressure state by this measurement. Since the correction values for the influence of are averaged, it is possible to perform even more accurate correction.

(Second Embodiment) The microwave densitometer according to the present embodiment differs from the microwave densitometer of the first embodiment described above with the passage of time, as shown in FIG. While increasing the pressurized pressure, continuously measure the concentration of the liquid to be measured by the microwave densitometer,
When the differential value of the measured value falls below a predetermined value (for example, a predetermined value close to zero), the measured value at that time is measured for the concentration of a mixed substance such as a solid content which is not affected by bubbles. It is configured to add the function of outputting as a value.

Next, in the microwave type densitometer of the present embodiment configured as described above, the pressurizing pressure is increased with time in the pressurizing / measuring step described in the first embodiment. As shown in FIG. 4, a differential value (ΔY / ΔP) of the measured value Y at the time of pressure increase is determined in the bubble influence correction computing unit 35, and the value is determined in advance. When the measured value becomes equal to or less than the predetermined value close to zero, the measured value at that time is output as a measured value of the concentration of a mixed substance such as a solid content which is not affected by bubbles.

That is, the first embodiment is applied to a case where a large amount of air bubbles is contained such that a large error does not occur even if the amount of air bubbles newly dissolved by pressurization is omitted in the calculation. On the other hand, the present embodiment can be applied to a case where the bubble content is such that the amount of bubbles dissolved by pressurization cannot be omitted.

[0073]

As described above, according to the microwave type densitometer of the present invention, even when the liquid to be measured contains a large amount of bubbles, the influence of the bubbles on the measured value is corrected. In addition, it is possible to accurately measure the concentration of a mixed substance such as a solid content in a liquid to be measured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment of a microwave densitometer according to the present invention.

FIG. 2 is a state diagram for explaining operation steps in the microwave densitometer of the first embodiment.

FIG. 3 is a conceptual diagram showing an example for explaining a pressurizing method applied to the present invention.

FIG. 4 is a characteristic diagram showing an example of a relationship between a pressurized pressure in a pressurization method applied to the present invention and a measurement value of a micro-wave densitometer.

FIG. 5 is a schematic diagram showing a basic configuration example of a conventional microwave densitometer.

FIG. 6 is a calibration curve for obtaining a concentration X from a phase difference Δθ,
The figure for demonstrating density | concentration X = a (DELTA) (theta) + b.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Microwave transmission antenna, 12 ... Microwave reception antenna, 13 ... Microwave oscillator, 14 ... Power splitter, 15 ... Phase difference measurement circuit, 21 ... Detector piping, 22 ... Automatic gate valve, 23 ... Measurement chamber cylinder, 24 ... Piston, 25 ... Seal material, 26 ... Pressure detector, 27 ... Piston position detector (for detecting sampling end position), 28 ... Piston position detector (for detecting pressurized position), 29 ... Piston position detector ( 30: pressurized pressure source, 31: pressure reducing mechanism, 32: switching valve, 33: controller, 34: concentration calculator, 35: bubble influence correction calculator.

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[Procedure amendment]

[Submission date] February 4, 2000 (200.2.4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

[0020]

In order to achieve the above-mentioned object, the invention according to claim 1 is directed to a test for flowing a liquid to be measured.
An output pipe, a measurement chamber attached to the detector pipe,
Microwave transmitters placed opposite each other with this measurement chamber
Communication antenna and microwave receiving antenna and this microphone
The measurement pair transmitted from the
Propagating the elephant fluid and receiving by the microwave receiving antenna
Phase measurement that measures and outputs the phase delay θ2 of the extracted microwave
Circuit and the phase delay θ2 from this phase measurement circuit,
Filling the reference liquid in the measurement chamber and the same conditions as the liquid to be measured
Comparison with microwave phase delay θ1
From the phase difference Δθ = (θ2−θ1), the measurement pair
Based on a calibration curve X = aΔθ + b corresponding to each type of elephant fluid
To measure the concentration X of the solid content of the liquid to be measured.
And each was measured at several different pressure conditions
The concentration calculation is performed based on a plurality of concentrations Y of the liquid to be measured.
Corrects the effect of bubbles on the concentration X measured by the instrument
And output the obtained measured concentration value CX.
A microwave densitometer provided with a calculator.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

[0022] The invention corresponding to claim 2 is defined in claim 2.
In the microwave densitometer corresponding to 1, the bubble shadow
As a sound-correction computing unit, three or more types of pressure
When the respective concentrations Y of the liquid to be measured are measured,
At the lowest pressure condition and at other pressure conditions
The correction values for the effects of bubbles calculated from
Measured by the density calculator based on the averaged correction value.
The effect of air bubbles at the specified concentration X is corrected and obtained.
Is a microwave densitometer that outputs the measured concentration CX
You.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

Further, the invention corresponding to claim 3 provides
In the microwave densitometer corresponding to item 1, the measurement
A pressurizing means for pressurizing the room is provided, and the bubble effect correction
As a device, the pressure in the measurement chamber by the pressurizing means
Measurement of the concentration of the liquid to be measured, which was continuously measured with the rise
The differential value calculated from the value, the differential value is set Me pre
And if the value falls below, concentrations measured value measured value at that time
You output as CX is a microwave densitometer.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

Further, if for example, the measurement chamber is provided on the side of the pipe the liquid to be measured is flowing, it is preferable to pressurize after sealing a portion of the liquid to be measured in the measurement chamber.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

Furthermore, For example, the measuring chamber is configured in cylindrical and it is preferable to pressurize the measurement chamber by a piston which slides therein.

Claims (6)

[Claims] 1. A microwave transmitting antenna and a microwave receiving antenna are opposed to each other so as to sandwich a liquid to be measured. Microwaves are incident on the reference liquid from the microwave transmitting antenna, propagate through the reference fluid, and The phase delay θ1 of the microwave received by the microwave receiving antenna is measured and stored in a memory, and the microwave is incident on the liquid to be measured from the microwave transmitting antenna and propagates through the liquid to be measured. Then, a phase delay θ2 of the microwave received by the microwave receiving antenna is measured, and a phase difference Δθ = (θ2−θ1) of each of the phase delays is calculated, corresponding to each type of the liquid to be measured. Calibration curve X = aΔθ +
In a microwave densitometer for measuring the concentration X of the liquid to be measured based on b, the concentration of the liquid to be measured is measured at a plurality of pressure states different from each other, and a plurality of measured values obtained by the measurement are measured. A microwave-type densitometer wherein the concentration of a mixed substance such as a solid content in the liquid to be measured is determined by correcting the influence of air bubbles by using the above method. 2. The microwave-type densitometer according to claim 1, wherein the plurality of different pressure states are measured as three or more types of pressures to measure the concentration of the liquid to be measured, and the lowest pressure state based on the measurement is performed. By averaging the correction value for the influence of air bubbles calculated from the measured value and the measured value in another pressure state, the concentration of the mixed substance such as solid content in the liquid to be measured is obtained. Microwave type densitometer. 3. The microwave type densitometer according to claim 1, wherein the concentration of the liquid to be measured is continuously measured while increasing the pressurized pressure with the passage of time, and the derivative of the measured value is differentiated. When the value falls below a predetermined value, means for outputting a measured value at that time as a concentration measured value of a mixed substance such as a solid content not affected by bubbles is added. Microwave densitometer. 4. The method according to claim 1, wherein
In the microwave concentration meter according to the paragraph, as one of the plurality of different pressure states,
A microwave densitometer characterized in that the atmospheric pressure (about 0.1 MPa) is set. 5. The method according to claim 1, wherein
In the microwave type densitometer according to the paragraph, a measurement chamber is provided on a side of a pipe through which the liquid to be measured flows, and a part of the liquid to be measured is collected in the measurement chamber, and after being sealed, pressure is applied. A microwave densitometer characterized in that: 6. The microwave densitometer according to claim 5, wherein the measurement chamber is formed in a cylindrical shape, and the measurement chamber is pressurized by a piston sliding inside the measurement chamber. Microwave type densitometer.