JP3572311B2 - Sea salt particle measuring device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The invention of this application relates to an apparatus for measuring the amount of sea salt particles. More specifically, the invention of this application relates to an apparatus for measuring the amount of sea salt particles, which is useful for a corrosion test of various metallic materials and a chemical elucidation of the corrosion process.
[0002]
[Prior art and its problems]
BACKGROUND ART Conventionally, great attention has been paid to the corrosion of various metal materials, particularly metal materials used as structural materials. In particular, when used in beach areas, sea salt particles flying from the sea have a large effect on corrosion, so when developing a metal material with good corrosion resistance, When examining the period, the amount of sea salt particles contained and scattered in the atmosphere is a factor that must be grasped as accurately as possible.
[0003]
Numerous methods have been devised for quantitative measurement of sea salt particles floating in the air. For example, the method for measuring the amount of sea salt particles specified in JIS-Z2381 and the method specified in ISO-9225 have been devised. The method of measuring the amount of sea salt particles has been adopted as a standard method.
The method for measuring the amount of sea salt particles according to JIS-Z2381 is called a dry gauze method. After leaving a dry gauze outdoors for a certain period of time so as not to get wet with rain, the flying sea salt attached to the gauze This is a method for analyzing the amount of particles.
[0004]
The method of measuring the amount of sea salt particles according to ISO-9225 is called a wet candle method. After a dry gauze is left outdoors for a certain period of time so that it does not get wet with rain, the gauze is replaced with water, an evaporation inhibitor. And a method of analyzing the amount of sea salt particles dissolved in the solution through the wet gauze.
[0005]
However, in any of such conventional methods, the amount of sea salt particles to be analyzed is an integrated value after a lapse of a certain period of time. It was impossible to capture in real time. Therefore, in the research and development of the corrosion-resistant metal material and the chemical elucidation of the corrosion process, there has been a serious problem that time loss is extremely large and changes in environmental conditions are not accurately reflected.
[0006]
Therefore, the invention of this application has been made in view of the above-mentioned drawbacks of the prior art, and the amount of flying sea salt particles that has the greatest effect on metal corrosion is reduced in response to changes in natural conditions, even in a short time. It is an object of the present invention to provide an apparatus for measuring the amount of sea salt particles which enables quantitative measurement as accurately as possible, in real time, automatically and continuously.
[0007]
[Means for Solving the Problems]
The invention of this application solves the above-mentioned problems, in which a quartz crystal micro-weight sensor and a humidity sensor are disposed inside a case body with a window that can be opened and closed, and a quartz crystal micro-weight sensor is provided. A measurement unit for a humidity sensor is provided. After the window is opened, the quartz oscillator micro-weight sensor is brought into contact with the atmosphere containing sea salt particles, and then the window is closed to obtain a high humidity of 50% or more relative humidity. The change (Δf ₁ ) of the resonance frequency of the crystal unit under the condition and the change (Δf ₂ ) of the resonance frequency of the crystal unit under the low humidity condition of 50% or less of relative humidity are measured, and Δf ₁ And measuring the amount of sea salt particles from the difference between the weight w ₁ calculated from the weight w ₁ and the weight w ₂ calculated from Δf ₂ .
[0008]
Further, in the present invention, the weight w ₁ obtained from the change in the resonant frequency of the crystal oscillator at high humidity conditions (Delta] f _1), by the amount of particles other than sea salt particles, other than sea salt The apparatus for measuring the amount of sea salt particles, wherein the amount of sea salt particles is measured while separating the amount of particles is also provided.
Further, the present invention also provides the above-described apparatus for measuring the amount of sea salt particles wherein the relative humidity is set to a high humidity condition of 80% or more and the low humidity condition is set to a relative humidity of 45% or less.
[0009]
In the invention of this application, a humidity control mechanism is provided, and this mechanism supplies a humidified air or a dry air, a sea salt particle amount measuring device, a data recording unit or a transmitting unit from a measuring unit. A sea salt particle amount measuring device, a sea equipped with a calculation instruction unit for automatic opening and closing of windows, automatic operation of a humidity control mechanism, automatic operation of a measuring unit, automatic operation of a recording unit or a transmitting unit. A device for measuring the amount of salt particles is also provided.
[0010]
The invention of this application having the features as described above, in the course of the examination by the inventor, in the high humidity state, sea salt particles exist as droplets, the droplets do not react with the crystal oscillator, It was found that the liquid droplets solidified under the humidity condition, and this solid reacted with the quartz oscillator, and furthermore, it was found that the weight of the minute object attached to the quartz oscillator surface could be measured as a change in the resonance frequency. It is based on the fact that it is possible to measure the amount of minute amounts of sea salt particles accurately, and even in real time, by utilizing such features. Furthermore, based on the new finding that the resonance frequency changes when the sea salt particles absorb moisture in the atmosphere and become droplets, separation of the sea salt particle components from other attached components is performed. The invention of this application has been completed as a device capable of performing this.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
In the apparatus for measuring the amount of sea salt particles according to the present invention, for example, as illustrated in FIG. 1 of the accompanying drawings, a case (1) has a window (2), and this window (2) is closed by a shutter (3). It can be opened and closed freely. A quartz oscillator micro-weight sensor (4) and a humidity sensor (5) are arranged in the case body (1), and a measurement unit (7) for these is provided. The measuring section (7) has a function of performing detection by the sensor and also oscillating the quartz oscillator.
[0012]
Further, the case body (1) is provided with a humidity control mechanism (6).
For example, in a measuring apparatus based on the above configuration, first, the quartz crystal micro-weight sensor (4) is brought into contact with the atmosphere containing sea salt particles in a state where the window (2) is opened, and sea salt particles are collected. .
In this case, the contact time between the crystal unit and the atmosphere can be selected in consideration of the purpose of measurement, natural environment conditions, the sensitivity of the crystal unit, and the like.
[0013]
Next, the window is closed by the shutter (3), and the quartz oscillator micro-weight sensor (4) from which the sea salt particles are collected is placed in the high humidity condition and the low humidity condition described above, and the crystal under each condition is set. Changes Δf ₁ and Δf _{2 in} the resonance frequency of the vibrator are measured.
At this time, in general, the high humidity condition is a condition where the relative humidity exceeds 50%, and the low humidity condition is a condition where the relative humidity is 50% or less. More preferably, the high humidity condition is a condition where the relative humidity is less than 50%. It is desirable that the humidity be 70% or more, and more preferably 80% or more. On the other hand, in the low humidity condition, the relative humidity is more preferably 45% or less.
[0014]
A humidifier or the like may be used as the humidity control mechanism (6) for forming the high humidity condition, and a dry air supply device or the like may be used for forming the low humidity condition. The humidity condition can be detected by a humidity sensor (5), for example, as shown in FIG.
From the value of the change Δf _{1 in} the resonance frequency of the crystal unit in the high humidity state, the weight w ₁ of the particles or the like adhered on the crystal unit micro weight sensor (4) is calculated according to the following relational expression.
[0015]
Next, the change Δf ₂ in the resonance frequency of the crystal unit is measured in a low humidity state. From this value, calculates the weight w ₂ of the particles or the like adhered onto the crystal resonator trace weight sensor (4).
Then, by obtaining the difference between w ₁ and w _2, to calculate the sea salt amount.
The quartz oscillator is not particularly limited, and for example, a commercially available quartz oscillator used for an electronic computer circuit or the like can be used. In addition, when used for a long time, the corrosion resistance of the electrode portion on the surface poses a problem. Therefore, it is desirable to use a material obtained by evaporating gold or the like on the electrode portion.
[0016]
Also, the measuring unit (7) is not particularly limited, and a commercially available circuit, for example, TR5822 manufactured by Advantest Corporation can be used.
Similarly, the humidity sensor (5) is not limited, and a commercially available humidity sensor, for example, Store Away RH manufactured by Onset Computer can be used.
[0017]
The relationship between humidity and the amount of sea salt particles in the apparatus for measuring the amount of sea salt particles is as follows.
Between the change Δf in the resonance frequency of the quartz oscillator and the weight w of the substance attached on the quartz oscillator micro-weight sensor,
w = − (Δf / f ₀ ) · NAρ
There is a relationship.
[0018]
Here, Delta] f is the change in the resonant frequency of the crystal oscillator, f ₀ is the reference frequency, A is the surface area, [rho represents the specific gravity.
When examining the change in humidity and the change in the resonance frequency of the crystal unit, the change Δf in the resonance frequency of the crystal unit does not become a constant value but decreases as the relative humidity decreases.
[0019]
This means that when the relative humidity is high, the sea salt particles are present as droplets and do not appear in the output of the crystal unit, but when the humidity is low, the droplets become solid and are output to the crystal unit. It is due to appearing.
In this case, from the above-described relational expression, it is conceivable that the weight of the sea salt particles attached to the surface of the crystal unit is reduced, but actually the result of observing the surface of the crystal unit with a microscope during measurement It has been confirmed that sea salt particles turn into water droplets.
[0020]
That is, by subtracting the output result under the low humidity condition from the output result of the crystal unit under the high humidity condition, a trace amount quantitative measurement of the amount of the sea salt particles can be performed.
Further, the reason why the change Δf in the resonance frequency of the crystal unit does not become 0 at the time of high humidity is that substances other than sea salt particles, for example, dust in gas, etc. adhere to the crystal unit. Can be
[0021]
Therefore, the amount of particles other than sea salt particles can be measured from this.
Except for the window (2) and the humidified or dry gas inlet (8), the case body (1) with a window that constitutes the device has no portion through which air enters and exits from outside to inside or from inside to outside. Not sealed. The internal volume needs to be such that a micro weight sensor (4) and a humidity sensor (5) made of quartz can be arranged inside.
[0022]
The window (2) is for introducing a gas containing sea salt particles from the outside of the device to the inside, and it is desirable that the window can be opened and closed by a shutter (3) for opening and closing the window. When the window (2) is closed, air does not enter or exit from outside to inside or from inside to outside.
The quartz oscillator micro-weight sensor (4) is placed inside the case (1) with a window, and a commercially available one is used. In order to prevent corrosion, 0.2 cm is applied to both sides of the quartz oscillator as described above. ^For example, a material obtained by depositing gold with a thickness of about 1 μm in an area of about ² can be used.
[0023]
The humidity control mechanism (6) supplies, for example, humidified or dry air to the case body (1) with a window through the inlet (8), and the air is supplied when the shutter (3) is closed. Is filled in the case. In the humidity control mechanism (6), a heater and / or silica gel may be used in the middle of the route.
The measuring unit (7) is arranged inside or outside the case (1) with a window, measures the outputs of the minute weight sensor (4) and the humidity sensor (5), and stores the data for at least one month. It is desirable to be able to.
[0024]
Actually, when the window is opened for 24 hours using the apparatus configuration of FIG. 1 and the change in humidity after closing the window and the output of the micro weight sensor are plotted, the result of FIG. 2 is obtained.
The relative humidity before opening the window was 95%, and after closing the window, the cell was filled with dry air to lower the relative humidity gradually to 40% or less. Accordingly, the output Δf of the trace weight measurement sensor has been similarly reduced. This is because when the relative humidity is high, the sea salt particles exist as droplets and do not appear in the output of the microgravimetric sensor. However, when the humidity decreases, the liquid droplets become solid and appear in the output of the microgravimetric sensor. That is, the amount of sea salt particles can be quantitatively measured by subtracting the result at low humidity from the result of the microgravimetric sensor at high humidity. From this result, it can be seen that the low humidity at that time needs to be 50% or less. In addition, the reason why Δf does not become 0 on the high humidity side is that substances other than sea salt particles, for example, dust in the air, adhere to the microgravimetric sensor. Can also be measured.
[0025]
f ₀ is 10 MHz, N is ^{1.67 × 10 8 Hz · mm,} A is the area of the surface 0.2 cm ^2, [rho is 2.648g / cm ^3.
For example, in the above configuration, it is easy to automate the measurement of the amount of sea salt particles in real time. For example, in the configuration of FIG. 1, an automatic opening / closing mechanism using a shutter (3) is provided, and an operation instruction device, a recording device, a transmitting / receiving device, and the like can be added.
[0026]
For example, as illustrated in FIG. 3, it is provided with a recording unit (9) and a calculation instruction unit (10), and the shutter (3) is first opened according to an instruction from the calculation instruction unit (10). The oscillator micro-weight sensor (4) is exposed to the atmosphere.
After a predetermined time, the shutter (3) is closed by an instruction from the calculation instruction unit (10), and the humidity detected by the humidity sensor (5) is sent to the calculation instruction unit via the measurement unit (7).
[0027]
The calculation instruction unit (10) determines whether the humidity in the closed case body (1) exceeds 50% or less than 50%, and instructs the humidity control mechanism (6) as necessary. To operate under high or low humidity conditions.
Under a predetermined condition, the operation instructing unit (10) instructs the measuring unit (7) to oscillate, and detects a change in the resonance frequency in the quartz oscillator micro-weight sensor (4). The detection data is sent to the recording unit (9) via the measurement unit (7) and instructed by the operation instruction unit (10), and is recorded.
[0028]
For example, as described above, the operation and measurement of the measuring device can be automated by the arithmetic and instruction device, and can be configured to record or transmit data.
In the present invention, although sea salt particles are the largest factor of metal corrosion outdoors, they could only be evaluated by an integrated value so far, but this can be quantitatively measured in real time, and automatic measurement is also possible. This is a revolutionary device.
[0029]
According to the present invention, the phenomenon of atmospheric corrosion can be predicted. For example, it is expected that the maintenance cost of conventional steel materials is reduced and the development of new steel materials is promoted.
Hereinafter, the present invention will be described in more detail with reference to Examples.
[0030]
【Example】
In the seaside area of Ginowan City, Okinawa Prefecture, H-shaped steel with a length of 5 m, which is used as a building material, is placed, and a sea salt particle amount measuring device having the configuration shown in FIG. Placed.
Then, every day at 9 am, the window was opened, the window was left open for 24 hours, the window was closed at 8:59 on the following day, the measurement was completed in about 1 minute, the window was opened again for 24 hours, and the same operation was performed. Repeated for one month.
[0031]
The results of quantitative measurement of the automatically measured amount of sea salt particles and the amount of other particles are as shown in FIG.
In FIG. 4, the horizontal axis represents the number of days after installation, and the vertical axis represents the amount of sea salt particles and other particles attached in units of mg / dm ² / d.
It can be seen that by using the apparatus of the present invention, the daily attached amount of sea salt particles and the attached amount of other particles other than sea salt particles can be separated and measured quantitatively.
[0032]
Further, according to the present invention, it is possible to quantitatively measure the daily amount of sea salt particles, which was impossible by the conventional method, and to obtain data effective for analysis in a corrosive environment outdoors.
[0033]
【The invention's effect】
As described above in detail, according to the present invention, the amount of incoming sea salt particles that have the most adverse effect on metal corrosion used for measuring the corrosive environment can be quantitatively measured in real time automatically and continuously at an outdoor metal corrosion test point. It is possible to do. Furthermore, the daily amount of sea salt particles and the amount of other particles other than sea salt particles can be separated and quantitatively measured.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an outline of a configuration of the present invention.
FIG. 2 is a relationship diagram illustrating the relationship among time, relative humidity, and Δf (change in resonance frequency of a quartz oscillator) in the device of the present invention.
FIG. 3 is a block diagram illustrating a configuration for an automation device.
FIG. 4 is a relationship diagram showing a temporal relationship between the amount of sea salt particles and the amount of other particles attached, according to the embodiment of the present invention.
[Explanation of symbols]
1 Case 2 Window 3 Shutter 4 Quartz Crystal Micro Weight Sensor 5 Humidity Sensor 6 Humidity Reduction Mechanism 7 Measurement Unit 8 Humidification or Dry Air Inlet 9 Recording Unit 10 Operation Instruction Unit

Claims (6)

A quartz crystal micro-weight sensor and a humidity sensor are arranged inside a case body with a window that can be opened and closed, and a measurement unit for a crystal micro-weight sensor and a humidity sensor is provided, and the window is opened. After the quartz oscillator micro-weight sensor is brought into contact with the atmosphere containing sea salt particles in the state, the window is closed, and the change in the resonance frequency of the quartz oscillator under the high humidity condition of a relative humidity exceeding 50%: Δf ₁ When the change in the resonant frequency of the crystal oscillator at low humidity conditions of 50% or less relative humidity: measured and Delta] f _2, the weight w ₂ obtained from the weight w ₁ and Delta] f ₂ obtained from Delta] f ₁ An apparatus for measuring the amount of sea salt particles, which measures the amount of sea salt particles from the difference. Change in the resonance frequency of the crystal oscillator at high humidity conditions: the weight w ₁ obtained from Delta] f _1, by the amount of particles other than sea salt particles, while the particles were separated volume other than sea salt, sea The apparatus for measuring the amount of sea salt particles according to claim 1, wherein the amount of salt particles is measured. 3. The apparatus according to claim 1, wherein a high humidity condition and a relative humidity of 80% or more are defined as high humidity conditions, and a relative humidity of 45% or less is defined as a low humidity condition. 4. The apparatus according to claim 1, further comprising a humidity control mechanism, wherein the mechanism supplies humidified air or dry air. The sea salt particle amount measuring device according to any one of claims 1 to 4, further comprising a recording unit or a transmitting unit for recording data from the measuring unit. The amount of sea salt particles according to any one of claims 1 to 5, further comprising a calculation instruction unit for automatically opening and closing the window, automatically operating the humidity control mechanism, automatically operating the measurement unit, and automatically operating the recording unit or the transmission unit. Measuring device.

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