JPH0618950U - Liquid physical property measuring device - Google Patents

Abstract

(57) [Summary] [Objective] To provide a measuring instrument capable of measuring a plurality of physical properties of a liquid with one device. [Structure] A container 31 containing a liquid 30 to be measured,
A transmitter 32 provided on one side surface of the container 31 for emitting a sound wave such as an ultrasonic wave to the liquid 30, and a receiver 33 provided on the other side surface of the container 31 for receiving a sound wave transmitted from the transmitter 32 via the liquid 30. And a measurement control unit 34 that is connected to the receiver 33 and the transmitter 32 and measures the propagation time of the sound wave and / or the attenuation rate of the amplitude of the sound wave.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a measuring device for measuring a physical property value of a liquid, and more particularly to a physical property value measuring device for a liquid in which a plurality of physical property values such as density and viscosity of the liquid are measured by one device.

[0002]

[Prior art]

 When measuring the density of a liquid, there are the following devices and methods.

1) Floating Scale FIG. 3 is a diagram showing the concept of a conventional floating scale.

As shown in FIG. 1, the floating scale is provided in a substantially floating container 2 having a scale (upper side in the figure) 1 provided with a scale and a body part (lower side in the figure) 3 of this container 2. It is formed by a weight 4 made of lead particles, and when this float balance is floated on the liquid 5 to be measured, the density of the liquid 5 can be measured by reading the scale of the part that matches the liquid surface. You can do it.

2) Vibrating Density Meter FIG. 4 is a diagram showing the concept of a conventional vibrating density meter.

As shown in FIG. 1, the vibrating densitometer includes a glass cell 10 made of a glass pipe whose upper end is fixed and bent into a substantially U shape, and a vibrating piece provided at the lower end of the glass cell 10. 11, an exciting head 12 arranged near the vibrating reed 11 to excite the vibrating reed 11 to vibrate the glass cell 10 in the direction of arrow P, and a detection head 13 for detecting a change in the magnetic field due to the vibration of the vibrating reed 11. And an amplifier 14 for maintaining the vibration, and the difference between the frequency when the glass cell 10 is emptied and the frequency when the liquid to be measured is put in the glass cell 10 It has come to seek the density.

In addition to this, there is a method of measuring the density by utilizing the speed of sound.

Further, when measuring the viscosity of a liquid, a cylindrical rotational viscometer is used.

FIG. 5 is a conceptual diagram of a conventional cylindrical rotational viscometer.

As shown in FIG. 1, the cylindrical rotational viscometer comprises a motor 22 provided above the liquid 20 to be measured so that the rotation shaft 21 is vertical, and a middle portion of the rotation shaft 21 of the motor 22. Of the graduation plate 23, a coil-shaped spring 24 hung at the lower end of the rotary shaft 21 of the motor 22, a cylinder 25 hung at the lower end of the spring 24, and the spring 24 and the cylinder 25. It consists of a needle 26, one end of which is fixed to the connection point and the other end of which is movably provided on the graduation plate 23. By reading the graduation when the cylinder 25 is rotated in the liquid 20 to be measured, The viscosity of the liquid 20 can be measured.

[0011]

[Problems to be solved by the device]

 However, when measuring the density and the viscosity, it is troublesome because separate measuring instruments must be used. Moreover, the floating balance and the cylindrical rotational viscometer cannot be used in an environment with vibration or shaking.

Therefore, an object of the present invention is to solve the above problems and to provide a measuring instrument capable of measuring a plurality of physical property values of a liquid with one device.

[0013]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a transmitter provided on one side surface of a container for emitting a sound wave such as an ultrasonic wave to a liquid and a transmitter provided on the other side surface of the container for transmission via a liquid. A receiver that receives the generated sound wave, and a measurement control unit that is connected to the receiver and the transmitter and that measures the propagation time of the sound wave and / or the attenuation rate of the amplitude of the sound wave are provided.

[0014]

[Action]

 According to the above configuration, it is possible to measure the propagation time of a sound wave such as an ultrasonic wave and / or the attenuation rate of the amplitude of the sound wave to be measured in the liquid to be measured. The density of the liquid can be determined, and the viscosity of the liquid can be determined from the attenuation rate of the sound wave amplitude. Therefore, one device can determine a plurality of measured values, that is, the density and / or the viscosity of a liquid.

[0015]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram of an embodiment of a liquid physical property value measuring device of the present invention.

In the figure, the physical property value measuring apparatus includes a container 31 for containing a liquid 30 to be measured, and an oscillator 32 provided on one side surface 31a (left side in the figure) of the container 31 for emitting a sound wave to the liquid 30. , A receiver 33 provided on the other side surface 31b (right side in the figure) of the container 31 for receiving a sound wave transmitted from the transmitter 32 via the liquid 30, and a sound wave transmission time connected to the transmitter 32 and the receiver 33. And a measurement control unit 34 that measures the attenuation rate of the amplitude of the sound wave. The measurement control unit 34 includes a transmission control unit 35 and a reception control unit 36.

The oscillator 32 is formed of, for example, a waterproof speaker that emits sound waves of an audible frequency and a low-frequency oscillator that is connected to a speaker and drives the speaker (both not shown).

The receiver 33 is formed of a waterproof microphone that converts sound waves into electric signals and an amplifier that is connected to the microphone and that amplifies the sound wave signals converted into electric signals (both not shown). ).

The transmission control unit 35 operates the oscillator 32 at the start of measurement, and the reception control unit 36 determines the time from when the acoustic wave is emitted from the oscillator 32 to when the acoustic wave is received by the receiver 33. In addition to the measurement, the ratio between the amplitude of the sound wave emitted from the transmitter 32 and the amplitude of the sound wave received by the receiver 33 is measured.

Next, the operation of the embodiment will be described.

FIG. 2A is a diagram showing a waveform of a sound wave emitted from the transmitter shown in FIG. 1, and FIG. 2B is an example of a waveform of a sound wave received by the receiver shown in FIG. It is a figure.

When the measurement is started, the transmission control unit 35 operates the oscillator 32 at time t ₀ , and emits a sine wave of amplitude A ₀ from the speaker (FIG. 2A). The sound wave emitted from the speaker is received by the receiver 33 at time t ₁ with the amplitude attenuated to A ₁ (FIG. 2B).

The reception control unit 36 obtains the difference Δt (= t ₂ −t ₁ ) between the time t ₁ and the time t ₂ and the ratio (attenuation rate) A ₁ / A ₀ between the amplitudes A ₁ and A _0. .

Here, Δt is determined by the speed of the sound wave that propagates in the liquid according to Equation 1.

[0026]

Where L is the distance from the transmitter 32 to the receiver 33, and v is the speed of the sound wave.

This velocity v is a function of the density ρ, as shown in Equation 2. Therefore, the density ρ can be obtained from Δt.

[0028]

## EQU00002 ## v = (K / .rho.) ^1/2 where K is a constant.

Further, the damping ratio A ₁ / A ₀ can be obtained by calculating the viscosity η as shown in Formula 3.

[0030]

## EQU00003 ## A ₁ / A ₀ = kη In the above, according to the present embodiment, the propagation time Δt of the sound wave transmitted in the liquid 30 to be measured and the attenuation rate A ₁ / A ₀ of the amplitude of the sound wave. Since both of the values can be measured, the sound velocity v can be obtained from the propagation time Δt, the liquid density ρ can be obtained from the sound velocity v, and the viscosity η of the liquid 30 can be obtained from the attenuation rate A ₁ / A _{0 of} the sound wave amplitude. I want it. Therefore, the values of both the density ρ and the viscosity η of the liquid can be obtained with one device.

In the present embodiment, the sound wave of the audible frequency is used as the sound wave emitted from the oscillator 32, but the sound wave is not limited to this and an ultrasonic wave may be used. However, in this case, needless to say, the frequency characteristic of the receiver 33 can also detect ultrasonic waves.

Further, in the present embodiment, the case where both the attenuation ratio of the sound wave amplitude and the arrival time of the sound wave are obtained has been described. However, even if either the strength or the arrival time of the received signal is measured. Good.

Further, although the present embodiment has been described in the case where the receiver is formed so as to receive the sound wave transmitted from the transmitter through the liquid, the present invention is not limited to this, and the container is miniaturized in order to make the container compact. The transmitter and receiver may be arranged to measure the sound waves reflected and transmitted through the liquid.

[0034]

[Effect of device]

 In short, according to the present invention, the following excellent effects are exhibited.

(1) Since a plurality of physical property values of the liquid, that is, viscosity and density can be measured by a plurality of single devices, workability is improved.

(2) Reliability can be improved because measurement can be performed without being affected even in an environment with vibration or shaking.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an embodiment of a liquid physical property value measuring device of the present invention.

2A is a diagram showing a waveform of a sound wave emitted from the transmitter shown in FIG. 1, and FIG. 2B is a diagram showing an example of a waveform of a sound wave received by the receiver shown in FIG. .

FIG. 3 is a diagram showing a concept of a conventional floating scale.

FIG. 4 is a diagram showing a concept of a conventional vibration type densitometer.

FIG. 5 is a conceptual diagram of a conventional cylindrical rotational viscometer.

[Explanation of symbols]

 30 liquid body 31 container 32 transmitter 33 receiver 34 measurement control unit 35 transmission control unit 36 reception control unit

Claims (1)

[Scope of utility model registration request] 1. A container for containing a liquid to be measured, a transmitter provided on one side surface of the container for emitting a sound wave such as an ultrasonic wave to the liquid, and the transmitter provided on the other side surface of the container. A receiver for receiving a sound wave transmitted from the liquid through the liquid, and a measurement control unit connected to the receiver and the transmitter, for measuring the propagation time of the sound wave and / or the attenuation rate of the amplitude of the sound wave. An apparatus for measuring a physical property value of a liquid characterized by the above.