CN105891050A - Variable magnetic field high-temperature melt oscillation viscometer and rapid measurement method thereof - Google Patents

Abstract

The invention discloses a variable magnetic field high temperature melt oscillating viscometer and a rapid measuring method thereof. system, the oscillation system includes a rotating power device, the bottom of the rotating power device is connected to the measuring rod through a suspension wire, and the bottom of the measuring rod is connected to the sample holding device in the heating device; An optical measurement system; the heating device is covered with a magnetic field system that can adjust the direction and intensity of the magnetic field so that the heating device is in a variable magnetic field. The magnitude and direction of the magnetic field at the sample are adjusted by changing the current and number of turns of the magnetic field coil. The optical measurement system obtains the logarithmic attenuation rate of the oscillation system through the laser signal reflected by the mirror, and the sample is obtained according to the relationship between viscosity and logarithmic attenuation rate. Viscosity data.

Description

A variable magnetic field high temperature melt oscillation viscometer and its rapid measurement method

technical field

The invention relates to a viscometer for measuring high-temperature melt viscosity by means of an oscillation method, in particular to a variable magnetic field high-temperature melt oscillation viscometer and a rapid measuring method thereof.

Background technique

Viscosity is an important physical parameter in the process of liquid solidification, which determines the material forming process and technology. The measurement and research of high-temperature melt viscosity are of great significance to both theoretical research and production practice. At present, the methods for measuring the viscosity of high-temperature melt mainly include capillary method, rotation method and oscillation method. The capillary method cannot measure high melting point metals, and the purity of the metal sample is extremely high, otherwise the capillary will be easily blocked and the measurement results will be wrong. The rotation method has extremely strict requirements on the motor and machinery, otherwise the accuracy of the viscometer is very low, the rotor is in direct contact with the sample, and the rotor may react with the sample, which limits the types of samples to be measured and cannot meet the needs of scientific research. For low-viscosity measured liquids such as high-temperature melts, ordinary rotational viscometers cannot meet the requirements at all. The oscillation method is currently the main method for measuring the viscosity of high-temperature melts. It uses an external force to make the sample liquid in the container undergo rotational vibration. Since the internal friction of the liquid consumes vibration energy, the rotational vibration of the system will slowly decay. The laser measures the logarithmic attenuation rate of the revolution, and obtains the viscosity data according to the relationship between the logarithmic attenuation rate and the viscosity. The traditional oscillation method has the problems of low measurement accuracy, long time consumption, and small measurement range, which no longer meets the current requirements.

The external magnetic field is an important means to control the solidification process and solidification structure of metal materials, and the study of the viscosity of metal melts under magnetic field conditions is an important research direction in the field of materials. However, there are still no reports on products for measuring the viscosity of high-temperature metal melts under magnetic field conditions at home and abroad.

Contents of the invention

The object of the present invention is to provide a variable magnetic field high-temperature melt oscillation viscometer and a rapid measurement method thereof to overcome the above-mentioned deficiencies in the prior art.

To achieve the above object, the present invention adopts the following technical solutions:

A variable magnetic field high-temperature melt oscillation viscometer, comprising a central plate, the upper part of the central plate supports a measuring container, and the lower part of the central plate is connected to a heating device; an oscillation system is provided in the measuring container, and the oscillation system includes a rotating power device, the bottom of the rotating power device is connected to the measuring rod through the suspension wire, and the bottom of the measuring rod is connected to the sample holding device in the heating device; the suspension wire is provided with an optical measurement system for measuring the logarithmic attenuation rate; the heating device coat There are magnetic field systems that can adjust the direction and strength of the magnetic field to place the heating device in a variable magnetic field.

The optical measurement system includes a reflector, a laser and a position sensitive detector, the reflector is fixed on the suspension wire, the laser and the position sensitive detector are outside the measuring container, and both the laser and the position sensitive detector are connected to the upper computer; The laser is emitted and irradiated on the reflector on the suspension wire. The laser is reflected back to the position sensitive detector through the reflector. The logarithmic decay rate is measured according to the position and time of the laser on the position sensitive detector.

The side wall of the measuring container is provided with a light hole corresponding to the reflector; the reflector is provided with an inertial disc; adjusting the inertial disc can change the moment of inertia of the entire oscillating system, and the viscosity range of different samples needs to be rotated accordingly. Inertia size. If the moment of inertia is not suitable, the oscillation of the system will decay too fast or too slow, making the measured logarithmic decay rate inaccurate. The oscillating system also includes a collet, the bottom of the rotary power device is connected to the collet, and the collet is connected to the suspension wire; the collet is convenient for connecting the motor to the suspension wire, and the collet is connected to the motor after clamping the suspension wire.

The top of the rotary power device is connected with an angle adjustment device, and the angle adjustment device includes a vacuum rotary introducer, which is arranged outside the measurement container; the vacuum rotary introducer is connected to the vacuum and the outside, and can be adjusted by using the vacuum rotary introducer. Transmits external rotation into the vacuum environment.

The magnetic field system includes an annular vertical magnetic field device and an annular horizontal magnetic field device, the upper and lower ends of the annular horizontal magnetic field device are provided with annular vertical magnetic field devices, and both the annular vertical magnetic field device and the annular horizontal magnetic field device are set on the heating device External: The circular vertical magnetic field device generates a vertical magnetic field after being energized, and the circular horizontal magnetic field device generates a horizontal magnetic field after being energized, providing a composite magnetic field for the sample in the sample holding device.

The annular vertical magnetic field device and the annular horizontal magnetic field device are all made of annular magnets, the annular vertical magnetic field device produces a vertical magnetic field when energized, and the annular horizontal magnetic field device generates a horizontal magnetic field when energized; by changing the current of the coil and The number of turns can adjust the size of the horizontal and vertical magnetic fields. According to the principle of vector addition, the size and direction of the total magnetic field received by the sample can be adjusted arbitrarily.

The suspension wire is a molybdenum wire, and the measuring rod is a molybdenum rod; the internal friction of molybdenum is small, and the influence on the system is small when the molybdenum wire is used for oscillation; the melting point of molybdenum is high, and the molybdenum rod can withstand the temperature of the heating furnace.

The heating device is a resistance furnace, and the resistance furnace is fixed on a hydraulic lifting device; the resistance furnace has the advantages of simple structure, uniform furnace temperature, easy control, good heating quality, no smoke and dust, and no noise; The furnace is lowered and the sample in the resistance furnace is replaced.

The top of the inner wall of the heating device is provided with a heat insulating sheet, and the upper part and the bottom of the heating device are provided with thermocouples.

The sample holding device is a crucible, and the bottom of the heating device is also equipped with a deoxygenating crucible; the metal in the deoxidizing crucible is a metal that is easy to react with oxygen, which can absorb oxygen during measurement, reducing the oxygen concentration in the furnace, thereby reducing the sample temperature. Oxidation during testing improves test accuracy.

An air inlet is provided at the bottom of the heating device, and an air outlet is opened on the side of the measuring container, and the air outlet is connected to a vacuum pump; the air inlet is connected to high-purity argon, after the vacuum is exhausted, close the air outlet and open the air inlet Flush with argon as shielding gas.

The bottom of the center plate is connected with a shock absorbing device; this ensures the verticality and stability of the entire oscillating system and makes the viscosity measurement more accurate.

A rapid measurement method of a variable magnetic field high-temperature melt oscillation viscometer, comprising the following steps:

Step 1: Carry out empty measurement of the viscometer: make the sample holding device fully empty, operate the rotating power device to drive the measuring rod to rotate, and according to the monitoring results of the optical measurement system, obtain the measuring rod rotation angle and The time fitting formula finally obtains the logarithmic decay rate λ ₀ and the oscillation period T ₀ during the air measurement;

Step 2: Place the sample to be tested in the sample holding device, vacuumize the measuring container, and fill it with an inert protective gas;

Step 3: Heat to above the melting point of the sample to be tested, and keep warm for 20-40 minutes;

Step 4: Turn on the power supply for the magnetic field system, adjust the magnetic field system, so that the sample to be tested is under the magnetic field condition of the set strength and direction;

Step 5: In the same way as Step 1, according to the monitoring results of the optical measurement system, obtain the fitting formula of the rotation angle and time of the measuring rod through the nonlinear least square method, and finally obtain the logarithmic decay rate λ and oscillation period T during the actual measurement ;

Step 6: Obtain the viscosity value of the sample to be tested according to the Shvidkovskiy relationship between logarithmic decay rate and viscosity.

The concrete steps of described step 1 are:

Step 1-1: When the sample holding device is in a static state, the optical measurement system records the deviation angle between the position of the laser on the position sensitive detector and the midpoint of the position sensitive detector;

Step 1-2: When the sample holding device is completely empty, operate the rotating power device to drive the measuring rod to rotate, and the optical measurement system records the position and time of the laser on the position sensitive detector, and converts it into the angle and time of rotation data;

Step 1-3: Obtain the following fitting formula for the rotation angle and time of the measuring rod by the nonlinear least square method, and obtain the logarithmic decay rate λ ₀ and the oscillation period T ₀ during the air measurement according to the obtained angle and time data:

In the formula, θ is the rotation angle of the measuring rod, θ _offset is the offset angle between the laser and the center of the position sensitive detector at rest, θ ₀ is the initial rotation angle, λ ₀ is the logarithmic decay rate, T ₀ is the oscillation period, t is time, is the initial phase angle.

Working principle of the present invention is:

The magnetic field system of the present invention generates a magnetic field by energizing the coil, and two groups of coils can generate horizontal and vertical magnetic fields at the sample respectively, and the size of the horizontal and vertical magnetic fields can be adjusted by changing the current and the number of turns of the coil. According to the principle of vector addition, the sample The size and direction of the total magnetic field received can be adjusted arbitrarily.

The optical measurement system of the present invention obtains the logarithmic decay rate of the oscillation system through the laser signal reflected by the mirror, and obtains the sample viscosity data according to the relationship between the viscosity and the logarithmic decay rate.

The beneficial effects of the present invention are:

The present invention adjusts the magnitude and direction of the magnetic field at the sample by changing the magnetic field coil current and the number of turns. The optical measurement system obtains the logarithmic decay rate of the oscillation system through the laser signal reflected by the mirror, and obtains the logarithmic decay rate according to the relationship between the viscosity and the logarithmic decay rate. The viscosity data of the sample is obtained, and the measurement of the viscosity of the metal melt under the condition of variable magnetic field is realized.

The viscometer of the present invention can greatly increase the amount of data obtained in one cycle by using a position sensitive detector, and improves the speed of viscosity measurement.

The design of the oxygen-removing crucible of the present invention can further reduce the oxygen concentration in the furnace, thereby reducing the oxidation of samples during testing and improving the accuracy of testing.

The central plate design of the present invention improves the stability of the oscillation system and improves the accuracy of testing.

Description of drawings

Fig. 1 is the structural representation of high temperature melt oscillation viscometer of the present invention;

2 is a schematic diagram of a variable magnetic field structure;

Fig. 3 is a schematic diagram of coil current direction and magnetic induction direction;

In the figure, 1 stepping motor, 2 chuck, 3 molybdenum wire, 4 light hole, 5 laser, 6 position sensitive detector, 7 molybdenum rod, 8 thermocouple, 9 sample crucible, 10 deoxygenating crucible, 11 cooling medium , 12 air inlet, 13 thermocouple, 14 horizontal coil, 15 vertical coil, 16 heat shield, 17 center plate, 18 inertia disk, 19 air outlet, 20 reflector, 21 measuring container, 22 resistance furnace, 23 angle adjustment device.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a variable magnetic field high temperature melt oscillating viscometer mainly includes an oscillating system, a heating system, a measuring system, a magnetic field system and a vacuum system. The stepping motor 1 on the top of the viscometer is connected to the low internal friction molybdenum wire 3 through the chuck 2, the lower end of the molybdenum wire 3 is connected to the molybdenum rod 7, and the lower end of the molybdenum rod 7 is connected to the sample crucible 9 containing the sample, and the sample crucible 9 can be a ceramic crucible .

The central plate 17 is supported on a horizontal plane, and there is a shock absorber at the bottom. The entire oscillation system is placed on the central plate 17, which ensures the verticality and stability of the entire oscillation system and makes the viscosity measurement more accurate. The upper part of the center plate 17 is fixed, so the resistance furnace 22 needs to be lowered to replace the sample in the crucible, and the lifting of the resistance furnace 22 is realized by the hydraulic device behind the resistance furnace 22.

The upper part of the viscometer is a measuring container 21 , the lower part of the viscometer is a resistance furnace 22 , and the measuring container 21 is supported on the center plate 17 . The viscometer heats the sample through a resistance furnace 22, a magnetic field system is placed outside the resistance furnace 22, and the magnitude and direction of the magnetic field at the sample are adjusted by changing the coil current and the number of turns; a reflector 20 is placed at the lower end of the molybdenum wire 3, and the optical measurement system passes The logarithmic decay rate of the oscillating system is obtained from the laser signal reflected by the mirror 20, and the sample viscosity data is obtained according to the relationship between the viscosity and the logarithmic decay rate.

The side wall of the measuring container 21 is provided with a light hole 4 corresponding to the reflector 20; the reflector 20 is provided with an inertial disc 18; the inertial disc 18 can change the moment of inertia of the entire oscillating system, and the viscosity range of different samples needs to be adjusted accordingly. Moment of inertia size. If the moment of inertia is not suitable, the oscillation of the system will decay too fast or too slow, making the measured logarithmic decay rate inaccurate. The measurement system includes a reflector 20, a laser 5 and a position sensitive detector 6, the reflector 20 is fixed on the molybdenum wire 3, the laser 5 and the position sensitive detector 6 are placed outside the viscometer, and the laser light emitted by the laser 5 is reflected by the reflector to On the position sensitive detector 6, the position change of the laser on the position sensitive detector 6 is converted into the angle change of the mirror 20 rotation, and the data of multiple angles changing with time are recorded, and the data is simulated by the computer using the nonlinear least square method. Together, the following formula 1 is obtained:

where θ is the rotation angle, θ _offset is the offset angle between the laser and the center of the position sensitive detector at rest, θ ₀ is the initial rotation angle, δ is the logarithmic decay rate, T is the oscillation period, t is the time, is the initial phase angle.

Traditional oscillatory viscometers use two fixed-position sensors to record oscillation data, and only four data can be recorded in one cycle, while this viscometer can greatly increase the amount of data obtained in one cycle by using position sensitive detector 6, improving speed of viscosity measurement.

The angle adjustment device 23 is located at the top of the viscometer, and the stepper motor 1 is fixed at its bottom, which is used to adjust the static angle of the entire oscillation system, so that the reflected laser light is located at the center of the position sensitive detector when the system is stationary, and it also ensures that the zero point is maintained when the system is oscillating Fixed position.

The oxygen-removing crucible 10 is placed on the bottom of the resistance furnace 22. In the oxygen-removing crucible 10, it is a metal that is easy to react with oxygen, which can absorb oxygen when measuring, and reduce the oxygen concentration in the furnace, thereby reducing the oxidation of the sample during testing and improving the testing efficiency. accuracy.

The top of the inner wall of the resistance furnace 22 is provided with a heat insulating sheet 16 , the upper part of the resistance furnace 22 is provided with a thermocouple 8 , and the inner bottom of the resistance furnace 22 is provided with a thermocouple 13 .

The bottom of the resistance furnace 22 is provided with an air inlet 12, and the side of the measuring container 21 is provided with an air outlet 19, and the air outlet 19 is connected to a vacuum pump; the air inlet 12 is connected to high-purity argon, and after the vacuum is exhausted, close the air outlet 19 and open The gas inlet 12 is flushed with argon as a shielding gas. The cooling medium 11 enters the resistance furnace 22 from the entrance at the bottom of the resistance furnace 22 to cool the resistance furnace.

As shown in Figures 2-3, the magnetic field system mainly includes two sets of coils, which are placed outside the resistance furnace 22. When the upper and lower sets of vertical coils 15 are energized, a vertical magnetic field is generated in the resistance furnace 22, and the middle horizontal coil 14 is in the resistance furnace. 22 to generate a horizontal magnetic field. By changing the current and turns of the coil, the magnitude of the horizontal and vertical magnetic fields can be adjusted. According to the principle of vector addition, the magnitude and direction of the total magnetic field that the sample receives can be adjusted arbitrarily.

The viscometer calculates the viscosity through the Shvidkovskiy formula, and the Shvidkovskiy formula is as follows:

$\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; I</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; T</span>}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; TW</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

in,

$\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}$

η=vρ

In the formula, υ is the kinematic viscosity, η is the absolute viscosity, I is the moment of inertia of the system, M is the mass of the sample, ρ is the density, R is the radius of the crucible, H is the height of the sample, a, b, c are the system constants, and T is the measured , T ₀ is the oscillation period during the air measurement, λ is the logarithmic decay rate during the actual measurement, and λ ₀ is the logarithmic decay rate during the air measurement.

Example 1:

The present invention measures pure aluminum viscosity method as follows:

1. Air test

1. Turn on the power of the device, wait for the empty sample crucible to be still, and the measurement system records the angle deviation between the position of the position-sensitive detector and the midpoint of the sensor when the laser reflected by the mirror is irradiated, that is, the θ _offset in formula 1 is obtained, and the θ _offset is The angle at which the laser is offset from the center of the position sensitive detector at rest.

2. The computer controls the stepping motor to rotate a certain angle and reset quickly, the sample crucible starts to rotate accordingly, the reflector and the sample crucible rotate synchronously, the laser emitted by the laser is reflected to the position sensitive detector through the reflector, and the measurement system records according to a certain frequency The position and time of the laser on a position sensitive detector is then converted into angular and time data of rotation.

3. At the same time, the computer uses the obtained angle/time data to perform the fitting of Formula 1, and obtain the logarithmic decay rate λ ₀ and the oscillation period T ₀ during the air measurement.

Second, the actual measurement

1. Lower the resistance furnace, put pure aluminum of mass M into the sample crucible, the sample volume is about 2/3 of the crucible volume, wait for the sample crucible to stand still, the measurement system records the laser irradiation reflected by the mirror and detects it sensitively at the position The angular deviation of the position of the sensor from the midpoint of the sensor.

2. Lift up the resistance furnace, seal the cavity, start the vacuum pump, turn off the vacuum pump after the vacuum inside the viscometer reaches below 10 ^-6 Pa, and feed pure Ar into the inside of the viscometer.

3. Turn on the resistance furnace to heat the sample to 700-800°C and keep it warm for 30 minutes.

4. The two sets of coils are powered on, and the current of the horizontal and vertical coils is adjusted to generate a magnetic field with a specific strength and direction at the sample.

5. Same as the air measurement operation, the logarithmic decay rate λ and oscillation period T during the actual measurement are obtained.

6. Bring the required data into the Shvidkovskiy formula to get the viscosity value of pure aluminum.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (10)

1. A variable magnetic field high-temperature melt oscillation viscometer is characterized by comprising a central plate, wherein the upper part of the central plate supports a measuring container, and the lower part of the central plate is connected with a heating device; an oscillation system is arranged in the measuring container and comprises a rotary power device, the bottom of the rotary power device is connected with a measuring rod through a suspension wire, and the bottom of the measuring rod is connected with a sample containing device in the heating device; an optical measuring system for measuring logarithmic decrement is arranged on the suspension wire; the heating device is sleeved with a magnetic field system capable of adjusting the direction and the strength of the magnetic field so as to enable the heating device to be in a variable magnetic field.

2. The variable magnetic field high temperature melt oscillation viscometer of claim 1, wherein the optical measurement system comprises a mirror, a laser and a position sensitive detector, the mirror is fixed on the suspension wire, the laser and the position sensitive detector are outside the measurement container, and the laser and the position sensitive detector are both connected with an upper computer; a light through hole is formed in the position, corresponding to the reflector, of the side wall of the measuring container; the reflecting mirror is provided with an inertia disc.

3. The variable magnetic field high temperature melt oscillation viscometer of claim 1 wherein the oscillation system further comprises a collet, the bottom of the rotary power unit being connected to the collet, the collet being connected to the suspension wire.

4. The variable magnetic field high temperature melt oscillation viscometer of claim 1 or 3 wherein the top of the rotary power unit is connected to an angle adjustment unit, the angle adjustment unit comprising a vacuum rotary introducer, the vacuum rotary introducer being disposed outside the measurement vessel.

5. The variable magnetic field high temperature melt oscillation viscometer of claim 1 or 2, wherein the magnetic field system comprises an annular vertical magnetic field device and an annular horizontal magnetic field device, the annular vertical magnetic field device and the annular horizontal magnetic field device are arranged at the upper end and the lower end of the annular horizontal magnetic field device, and the annular vertical magnetic field device and the annular horizontal magnetic field device are sleeved outside the heating device.

6. The variable magnetic field high temperature melt oscillation viscometer of claim 5 wherein the annular vertical magnetic field device and the annular horizontal magnetic field device are each comprised of an annular magnet, the annular vertical magnetic field device producing a vertical magnetic field when energized and the annular horizontal magnetic field device producing a horizontal magnetic field when energized.

7. The variable magnetic field high temperature melt oscillation viscometer of claim 1, wherein the suspension wire is a molybdenum wire and the measuring rod is a molybdenum rod; the heating device is a resistance furnace which is fixed on the hydraulic lifting device; the bottom of the central plate is connected with a damping device.

8. The variable magnetic field high temperature melt oscillation viscometer of claim 1, wherein a heat shield is provided on the top of the inner wall of the heating device, and thermocouples are provided on both the top and bottom of the heating device; the sample containing device is a crucible, and the bottom of the heating device is also provided with a deoxidizing crucible; the bottom of the heating device is provided with an air inlet, the side part of the measuring container is provided with an air outlet, and the air outlet is connected with a vacuum pump.

9. A method for rapid measurement using a variable magnetic field high temperature melt oscillation viscometer of any one of claims 1 to 8 including the steps of:

step 1: carrying out empty measurement of the viscometer: the sample containing device is operated to drive the measuring rod to rotate in a full-empty state, a fitting formula of the rotation angle and time of the measuring rod is obtained through a nonlinear least square method according to the monitoring result of the optical measuring system, and finally the logarithmic decrement lambda in the empty measurement is obtained₀And period of oscillation T₀；

Step 2: placing a sample to be measured in a sample containing device, vacuumizing a measuring container, and filling inert protective gas;

and step 3: heating to a temperature above the melting point of the sample to be measured, and preserving heat for 20-40 minutes;

and 4, step 4: switching on a power supply for the magnetic field system, and adjusting the magnetic field system to enable the sample to be detected to be in a magnetic field condition with set strength and direction;

and 5: in the same way as the step 1, according to the monitoring result of the optical measurement system, obtaining a fitting formula of the rotation angle and time of the measuring rod by a nonlinear least square method, and finally obtaining the logarithmic decrement lambda and the oscillation period T in the actual measurement;

step 6: and obtaining the viscosity value of the sample to be measured according to the Shvidkovskiy relation between the logarithmic decrement and the viscosity.

10. The rapid measurement method according to claim 9, wherein the step 1 comprises the following steps:

step 1-1: when the sample containing device is in a static state, the optical measuring system records the deviation angle between the position of the laser on the position sensitive detector and the midpoint of the position sensitive detector;

step 1-2: the sample containing device is in a full-empty state, the rotary power device is operated to drive the measuring rod to rotate, and the optical measuring system records the position and time of the laser on the position sensitive detector and converts the position and time into rotating angle and time data;

step 1-3: obtaining the following fitting formula of the rotation angle and time of the measuring rod by a nonlinear least square method, and obtaining the logarithmic decrement lambda in the air time according to the obtained angle and time data₀And period of oscillation T₀：

In which theta is the rotation angle of the measuring rod theta_offsetIs the offset angle theta of the laser from the center of the position sensitive detector at rest₀At an initial angle of rotation, λ₀Is logarithmic decay rate, T₀Is the period of oscillation, t is the time,is an initial phase angle.