JP2010203992A - Viscosity sensor and method of measuring viscosity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a viscosity sensor that facilitates measuring viscosity of a wide range of substrates including liquids. <P>SOLUTION: The viscosity sensor 100 includes a first housing 10, a second housing 20, an isolator 30 forming a sealed space 32 by connecting the first housing 10 and the second housing 20 and isolating the propagation of the vibration between the first housing 10 and the second housing 20, and a vibration piece 40 contained in the sealed space 32, having a base 42 fixed to the second housing 20 and an arm 44 extending from the base 42, in which the vibration of the arm 44 of the vibration piece 40 is leaked out to the base 42 and the second housing 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a viscosity sensor and a viscosity measuring method.

  A method for measuring the viscosity of a liquid by bringing a vibrator into contact with the liquid is known. For example, in Patent Document 1, a flat crystal resonator is immersed in a liquid such as oil, and the crystal resonator is oscillated. I. A crystal oscillator for a viscosity sensor that detects the viscosity of a liquid by observing a value (crystal impedance) is disclosed.

  Patent Document 2 discloses a piezoelectric vibrator for a viscosity sensor similar to Patent Document 1. In Patent Document 2, a holder or the like for holding a vibrating piece of a piezoelectric vibrator for a viscosity sensor is chrome-plated, and each member does not sulfidize even when it comes into contact with the oil to be measured. There is a description that can be improved.

JP 2004-128979 A JP 2008-008822 A

  However, the measurement target of a viscosity sensor using a conventional vibrator is limited to a fluid having a viscosity equal to or lower than a viscosity that has fluidity. That is, it has been difficult to measure the viscosity (viscosity) of a very viscous fluid or a viscoelastic body such as plastic. The reason is that if the viscosity of the measurement object is too high, the vibration of the vibrator serving as the probe is hindered when contacting the measurement object. I. For example, the value becomes so large that the sensor cannot oscillate.

  In addition, since the vibration portion of the conventional vibrator is in direct contact with the measurement target, it is necessary to perform a treatment for preventing corrosion on each member.

  One of the objects according to some embodiments of the present invention is to provide a viscosity sensor that can easily measure the viscosity of a wide range of substances including liquids.

  One of the objects according to some embodiments of the present invention is to provide a highly reliable and reproducible viscosity sensor.

  One of the objects according to some embodiments of the present invention is to provide a method for easily measuring the viscosity of a wide range of substances including liquids using a vibrating piece.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
A first housing;
A second housing;
An isolator for connecting the first housing and the second housing to form a sealed space, and isolating vibration propagation between the first housing and the second housing;
A vibrating piece having a base portion housed in the sealed space and fixed to the second housing and an arm portion extending from the base portion;
Including
A viscosity sensor in which vibration of the arm portion of the vibrating piece leaks to the base and the second housing.

  Such a viscosity sensor can easily measure the viscosity of a wide range of substances including liquids. Such a viscosity sensor can measure the viscosity of the measurement object using leakage vibration derived from the vibration of the arm. Therefore, when measuring the viscosity of a liquid having a very high viscosity or a viscoelastic body, the vibration piece can continue to oscillate without stopping even if the vibration of the measurement unit is suppressed. In addition, such a viscosity sensor can measure viscosity with high reliability and reproducibility because the vibrating piece is accommodated in the sealed space and the arm portion of the vibrating piece does not directly contact the measurement target. .

[Application Example 2]
In application example 1,
The vibrating piece includes an electrode formed on the arm portion, and a wiring formed on the base portion and electrically connected to the electrode,
The first housing has a terminal for electrical connection from the outside to the inside,
The wiring is a viscosity sensor electrically connected to the terminal in the sealed space.

  Such a viscosity sensor can measure the viscosity with higher reliability and reproducibility because the electrical connection to the vibrating piece is accommodated in the sealed space.

[Application Example 3]
In application example 1 or application example 2,
The vibration piece is a tuning fork type vibration piece, a viscosity sensor.

  Since such a viscosity sensor uses a tuning-fork type vibration piece whose vibration characteristics are easy to control, the viscosity can be measured with higher reliability and reproducibility.

[Application Example 4]
In any one of the application examples 1 to 3,
The base of the vibration piece is a viscosity sensor that penetrates the second housing.

  Such a viscosity sensor can directly measure the viscosity with high sensitivity because the base of the resonator element can be brought into direct contact with the object to be measured.

[Application Example 5]
In any one of the application examples 1 to 3,
A viscosity sensor, wherein a contact piece is further provided outside the position where the base portion of the second housing is fixed.

  Since such a viscosity sensor has a contact piece that vibrates together with the second housing, the contact with the measurement object is facilitated, and the viscosity can be measured with high sensitivity, reliability, and reproducibility.

[Application Example 6]
In any one of the application examples 1 to 4,
The vibration piece is a viscosity sensor in which impedance changes in response to a change in magnitude of vibration of the base when at least one of the base and the second housing is in contact with a measurement target.

  In such a viscosity sensor, since the impedance of the vibration piece responds sensitively to changes in leakage vibration, the viscosity can be measured with higher sensitivity, reliability, and reproducibility.

[Application Example 7]
In application example 5,
The contact piece vibrates due to leakage vibration leaking from the arm portion,
The vibration piece is a viscosity sensor in which an impedance changes in response to a change in magnitude of vibration of the base portion when at least one of the contact piece and the second housing comes into contact with a measurement target.

  In such a viscosity sensor, since the impedance of the vibration piece responds sensitively to changes in leakage vibration, the viscosity can be measured with higher sensitivity, reliability, and reproducibility.

[Application Example 8]
A viscosity measuring method using a vibrating piece having a base and an arm extending from the base, the impedance of which changes when the vibration of the base changes,
Inputting a drive signal to the arm portion of the vibrating piece to vibrate the arm portion and the base portion;
Contacting the base directly or indirectly with a measurement object;
Detecting a change in vibration of the base as a change in impedance of the vibrating piece;
Viscosity measurement method including

  In this way, the viscosity of a wide range of substances including liquid can be easily measured. That is, the viscosity of the measurement target can be measured using leakage vibration derived from the vibration of the arm portion. Therefore, when measuring the viscosity of a liquid having a very high viscosity or a viscoelastic body, it is possible to continue to oscillate without stopping the resonator element even when the vibration of the base is suppressed.

FIG. 3 is a partially cut cross-sectional view schematically showing the viscosity sensor 100 of the embodiment. FIG. 6 is a plan view schematically showing the resonator element according to the embodiment. The oscillation circuit and block diagram of the viscosity sensor of an embodiment. The simplified equivalent circuit schematic of the viscosity sensor of embodiment. The fragmentary sectional view which shows typically the viscosity sensor 200 of a modification. The fragmentary sectional view which shows typically the viscosity sensor 300 of a modification. The fragmentary sectional view which shows typically the principal part of the viscosity sensor of a modification. The fragmentary sectional view which shows typically the principal part of the viscosity sensor of a modification. The top view which shows typically the principal part of the viscosity sensor of a modification. The fragmentary sectional view which shows typically the principal part of the viscosity sensor of a modification.

  Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the following embodiment demonstrates an example of this invention.

1. Viscosity Sensor FIG. 1 is a partially cut sectional view schematically showing a viscosity sensor 100 according to an embodiment. FIG. 2 is a plan view schematically showing the resonator element 40.

  The viscosity sensor 100 includes a first housing 10, a second housing 20, an isolator 30, and a vibrating piece 40.

  As shown in FIG. 1, the first housing 10 is a part of a housing that seals the vibrating piece 40 of the viscosity sensor 100. The first housing 10 is one member that is connected to the isolator 30 and forms a sealed space 32 inside the viscosity sensor 100. Neither the cross-sectional shape nor the planar shape of the first housing 10 is limited. In the example of FIG. 1, it has a container-like shape that covers the top of the resonator element 40, but it may be a flat plate or the like by appropriately selecting the shape of the isolator 30 or the like. The first housing 10 is one of the non-vibrating portions (non-vibrating portions) in the viscosity sensor 100, so that the viscosity sensor 100 can be supported by the first housing 10. Examples of the material of the first housing 10 include metals and ceramics, and are not particularly limited as long as the material can form the sealed space 32.

  The first housing 10 may be provided with a terminal 12 for making an electrical connection from the outside to the inside of the viscosity sensor 100 (from inside to outside). The required number of terminals 12 can be provided. The terminal 12 is provided to be electrically insulated from the first housing 10 when the first housing 10 is formed of a conductive material. In the example shown in FIG. 1, two hermetic seal terminals are depicted in which a conductive core is covered with an insulating sheath. By providing such a terminal 12, the electrode and the like of the vibrating piece 40 in the sealed space 32 and the external circuit can be electrically connected while the viscosity sensor 100 is kept sealed.

  The second housing 20 is connected to an isolator 30 as shown in FIG. The second housing 20 is one of the members for forming the sealed space 32 inside the viscosity sensor 100. The cross-sectional shape and the planar shape of the second housing 20 are not limited. In the example of FIG. 1, the plate-like shape is provided below the vibrating piece 40, but it may be a vessel shape or the like by appropriately selecting the shape of the isolator 30. The 2nd housing 20 functions as a probe (measurement part) of the viscosity sensor 100 for making it contact with a measuring object. Examples of the material of the second housing 20 include metals, ceramics, and the like, and any material that can form the sealed space 32 is not limited. In the example shown in FIG. 1, the second housing 20 comes into contact with the measurement target, and therefore, it is more preferable that the second housing 20 be formed of a material that is chemically and mechanically stable with respect to the measurement target. As an example of such a material, for example, at least the outer surface of the second housing 20 can be formed of a stable metal such as gold or chromium, or the outer surface can be coated with a polymer material. .

  The second housing 20 is one of the parts of the viscosity sensor 100 that vibrate. At least the end surface of the base 42 of the resonator element 40 is fixed to the second housing 20. Examples of the method for fixing the base portion 42 of the resonator element 40 to the second housing 20 include bonding with an adhesive, metal brazing material, welding such as plasma welding and seam welding, and ultrasonic bonding. it can. In the example of FIG. 1, the base 42 is fixed to the second housing 20 by forming the adhesive layer 22. Examples of the adhesive used when fixing the base 42 with the adhesive layer 22 include an epoxy-based, acrylic-based, or glass-based adhesive. In order to transmit the vibration of the base 42 to the second housing 20 more efficiently. In addition, it is preferable to use an adhesive having as much hardness as possible.

  The isolator 30 is a member that connects the first housing 10 and the second housing 20. When the first housing 10 and the second housing 20 are connected by the isolator 30, a sealed space 32 is formed inside. The isolator 30 has a function not to propagate (isolate) the vibration of the second housing 20 to the first housing 10. Examples of the structure of the isolator 30 include a structure that can suppress the propagation of vibration while forming the sealed space 32, such as a bellows structure and a diaphragm structure. In the example of FIG. 1, the isolator 30 has a bellows structure. The shape of the details of the isolator 30 is arbitrary as long as it can be connected to the first housing 10 and the second housing 20.

  Examples of the material of the isolator 30 include metals and plastics. Further, as a material of the isolator 30, it is more preferable that the isolator 30 is formed of a material that is stable with respect to the measurement target in case the isolator 30 contacts the measurement target. In such a case, for example, at least the outer surface of the isolator 30 can be formed of a stable metal such as gold or chromium, or the surface can be coated with a polymer material or the like.

  The isolator 30 can be connected to the first housing 10 and the second housing 20 by, for example, adhesion using an adhesive, a metal brazing material, welding such as plasma welding or seam welding, and ultrasonic bonding. it can. The sealed space 32 formed by the first housing 10, the second housing 20, and the isolator 30 may have a pressure smaller than atmospheric pressure as long as the function of the isolator 30 is not impaired. Further, nitrogen, inert gas, or the like may be enclosed in the sealed space 32.

  The vibrating piece 40 is accommodated in the sealed space 32. The vibration piece 40 includes a base portion 42 and an arm portion 44 extending from the base portion 42. The vibration piece 40 is formed so as to have vibration leakage in which the energy of vibration of the arm portion 44 leaks to the end surface of the base portion 42. Any vibration piece 40 can be used as long as it has vibration leakage from the arm portion 44 to the base portion 42. Examples of the vibrating piece 40 include a single beam type vibrating piece, a tuning fork type vibrating piece, and a walk type vibrating piece. Any of the illustrated resonator elements may take a form having a base portion 42 and an arm portion 44 extending from the base portion 42. The resonator element 40 can be formed of a piezoelectric material such as quartz, lithium tantalate, or lithium niobate, for example.

  In the present embodiment, an example in which the vibrating piece 40 is a tuning fork type vibrating piece is illustrated. As shown in FIG. 2, the vibrating piece 40 is formed in a cantilever shape in which two arm portions 44 protruding from the base portion 42 have base ends. These two arm portions 44 extend in the same direction.

  A plurality of electrodes 46 are formed on the arm portion 44. The electrode 46 is formed on the surface of the arm portion 44. An electric field can be applied to the piezoelectric material constituting the arm portion 44 by the electrode 46. Thereby, the arm part 44 can be bent. And the arm part 44 can bend and vibrate by alternating the direction of the applied electric field.

  The arrangement of the electrode 46 provided on the arm portion 44 is arbitrary as long as the arm portion 44 can be bent. In the example of FIG. 2, electrodes 46 are provided on the front surface side and the back surface side of the arm portion 44. At least two electrodes 46 are provided for one arm portion 44, and the two electrodes 46 are electrically connected by a wiring 48 so that they have different potentials. The wiring 48 can be formed on the front surface side, back surface side, and side surface of the arm portion 44. The wiring 48 may also serve as the weight portion 49 in the arm portion 44. The weight portion 49 can be formed near the tip of the arm portion 44. The weight 49 can be used to adjust the frequency of vibration of the arm 44. The wiring 48 extends from the arm portion 44 to the base portion 42.

  In the illustrated example, two wires 48 are drawn out to the base 42. A voltage signal can be applied to each electrode 46 via each wiring 48. In the base portion 42, the wiring 48 may have a pad 47 as shown. Thereby, the connection to the vibration pieces 40, such as the bonding wire 50, can be facilitated. Examples of the material of the electrode 46 and the wiring 48 include Cr and Au, and a laminated structure thereof may be used.

  The wiring 48 is connected to one end of the bonding wire 50 at the base 42. The other end of the bonding wire 50 is connected to the terminal 12 provided in the first housing 10. In this way, an electrical connection from the electrode 46 to the terminal 12 is formed in the sealed space 32 inside the first housing 10. The terminal 12 can be electrically connected to an external circuit or the like (not shown) outside the first housing 10. As the bonding wire 50, for example, a gold wire can be used. It is more preferable that the bonding wire 50 be formed thin enough not to hinder the operation of the base portion 42. The bonding wire 50 may be formed in a winding shape so as not to hinder the operation of the base portion 42.

  By adopting the structure of the electrode 46 and the wiring 48 as described above and applying a voltage signal from the outside, the two arm portions 44 can bend and vibrate so as to approach and separate from each other.

  The vibration piece 40 is formed such that the vibration of the arm portion 44 is propagated from the arm portion 44 to the base portion 42. In other words, the base portion 42 and the arm portion 44 of the vibrating piece 40 are formed so that the vibration of the arm portion 44 leaks to the base portion 42. In the case of a tuning fork type vibrating piece, for example, one arm of the arm 44 is made larger than the other, one arm 44 is made longer than the other, and the electrode 46 is arranged in two arms. If the resonator element 40 is formed by making the two arms 44 asymmetrical, a combination thereof, and the like, the vibration of the arms 44 can be leaked to the base 42. . The vibration of the base 42 is propagated to the second housing 20 to which the base 42 is fixed, and the second housing 20 vibrates together with the vibration of the base 42. In the case of the vibrating piece 40 shown in FIG. 2, the tuning fork type vibrating piece as the reference signal source does not have a configuration such as a through hole or a notch formed in the base portion 42 in order to suppress propagation of vibration energy. . For example, by not having such a configuration, the vibration of the arm portion 44 can be easily leaked to the base portion 42.

  In the viscosity sensor 100 described above, the vibrating piece 40 is accommodated in the sealed space 32. Therefore, in the viscosity sensor 100, the arm portion 44 of the vibrating piece 40 does not directly contact the measurement target. Therefore, the viscosity of a wide range of substances including liquid can be easily measured with high reliability and reproducibility.

2. Viscosity Detection by Viscosity Sensor and Operation of Viscous Sensor The following describes the viscosity detection by the viscosity sensor and the operation of the viscosity sensor.

FIG. 3 is an example of a circuit diagram of an oscillator that oscillates the viscosity sensor 100 and an example of a block diagram for measuring viscosity. FIG. 4 is a simplified equivalent circuit diagram illustrating the operation of the viscosity sensor 100. C of FIG. 4 ₀ represents the capacitance between different electrodes 46 (and / or wire 48) of the potential in the entire viscosity sensor 100.

  The oscillation circuit 200 includes an amplifier 212, a feedback resistor 214, a resistor 222, and capacitors 224 and 226, and is connected to the viscosity sensor 100.

  The viscosity sensor 100 can be driven by the oscillation circuit 200 as described above. Since the amplitude of the output signal 102 of the viscosity sensor 100 changes depending on the viscosity of the measurement target, for example, as shown in the figure, the output signal 102 is output as a voltage through a buffer, a rectifier, and a smoothing circuit. Thus, the viscosity of the measurement object can be measured.

When the viscosity sensor 100 comes into contact with the measurement target, the vibration of the base 42 changes depending on the viscosity of the measurement target. That is, when the viscosity sensor 100 contacts the measurement object, the equivalent series resistance r1 changes as shown in FIG. At this time, the greater the viscosity of the measurement target, the more the vibration energy of the base 42 is dissipated from the measurement target, and the equivalent series resistance r1 increases. If the viscosity of the measurement object is very large, the vibration of the base 42 will stop, the equivalent series resistance r1 will exhibit a maximum value r _max. The equivalent series resistance r1 is the so-called C.I. when the viscosity sensor 100 is made of quartz. I. Corresponds to the value (crystal impedance).

Here, if the absolute value of the negative resistance (−R) of the oscillation circuit 200 is designed to be larger than r _max in advance, even if the vibration of the base portion 42 is completely stopped, the bending of the arm portion 44 is not performed. A resonance state in vibration can be maintained.

  Thus, in the viscosity sensor 100 of the present embodiment, a part of the energy given from the outside to vibrate the arm part 44 is consumed to vibrate the base part 42. The energy for vibrating the base 42 can be, for example, 10 to 70% of the energy given to drive the viscosity sensor 100. That is, even if the vibration energy of the base portion 42 is completely dissipated, the arm portion 44 can vibrate with the remaining 90 to 30% of energy.

  As described above, in the viscosity sensor 100 according to the present embodiment, for example, when measuring the viscosity of a liquid having a very high viscosity or a viscoelastic body, the vibration piece stops even if the vibration of the measurement unit is suppressed. It is easy to measure these viscosities. In addition, the viscosity sensor 100 of the present embodiment can measure the viscosity with high sensitivity because the impedance (equivalent series resistance r1) of the resonator element 40 is very sensitive to changes in leakage vibration. .

  Examples of measurement objects whose viscosity can be measured by the viscosity sensor of the present embodiment include a wide range of substances, such as gas, liquid, liquid with high viscosity, resin, living body, and the like.

3. FIG. 5 is a partially cut cross-sectional view schematically showing a viscosity sensor 300 according to a modification of the present embodiment. FIG. 6 is a partially cut cross-sectional view schematically showing a viscosity sensor 400 according to another modification of the present embodiment. FIG. 7 is a diagram schematically showing a main part of a modified example of the viscosity sensor. FIG. 8 is a partially cut cross-sectional view schematically showing a main part of a modified example of the viscosity sensor. FIG. 9 is a cross-sectional view schematically showing the main part of a modified example of the viscosity sensor. FIG. 9 corresponds to a cross section taken along line AA of FIG. FIG. 10 is a cross-sectional view schematically showing a main part of a modified example of the viscosity sensor.

  The viscosity sensor 300 according to the modification shown in FIG. 5 is the same as the viscosity sensor 100 except that the form of the isolator is different. Therefore, description of other members is omitted. The structure of the isolator 34 of the viscosity sensor 200 is a diaphragm structure. The material of the isolator 34, the connection between the isolator 34 and the first housing 10 and the second housing 20, and the like are the same as those of the isolator 30 of the viscosity sensor 100.

  The viscosity sensor 400 according to another modification shown in FIG. 6 is the same as the viscosity sensor 100 except that the shape of the vibrating piece is different. Therefore, description of members other than the resonator element is omitted. The vibration piece 41 of the viscosity sensor 400 includes two wiring branch portions 43 that protrude from the base portion 42 and extend in parallel with the arm portion 44. The wiring 48 extends from the base 42 to each wiring branch 43.

  The two wiring branch portions 43 have a base end at the base portion 42 and are formed in a cantilever shape. The wiring branch 43 can be formed so that vibration does not leak from the base 42. The wiring branch portion 43 can be formed of the same material as that of the vibrating piece 41 and can be formed integrally. As a function of the wiring branch portion 43, the length of the bonding wire 50 can be shortened in the sealed space 32. That is, the formation of the wiring branch portion 43 can reduce a problem that the bonding wire 50 contacts each member due to vibration or the like in the sealed space 32. Therefore, the viscosity sensor can be reduced in size.

  Further, a modified example of the viscosity sensor portion will be described. As shown in FIG. 7, the viscosity sensor of the present embodiment is further provided with a contact piece 26 outside the position where the base 42 of the second housing 20 is fixed. The contact piece 26 can vibrate together with the second housing 20. The contact piece 26 may be integrated with the second housing 20 and bonded to the second housing 20 by bonding with an adhesive, paste, brazing material, etc., welding such as plasma welding or seam welding, and ultrasonic bonding. May be. In the example of FIG. 7, the adhesive layer 28 is formed and the contact piece 26 is fixed to the second housing 20. The adhesive layer 28 is the same as the adhesive layer 22 described above. The contact piece 26 has a function of easily transmitting the vibration of the viscosity sensor (second housing 20) to the measurement target. In the illustrated example, the contact piece 26 is drawn in a rectangular parallelepiped shape, but the shape of the contact piece 26 is arbitrary.

  As shown in FIGS. 8 and 9, the viscosity sensor of the present embodiment can be provided with a base portion 42 of the vibrating piece 40 penetrating the second housing 20. In this way, since the base 42 can be brought into contact with the measurement object, the sensitivity of the viscosity sensor can be further improved. Examples of the method of fixing the base 42 to the second housing 20 in this case include adhesion with an adhesive, paste, brazing material, etc., welding such as plasma welding and seam welding, and ultrasonic bonding. 8 and 9, the adhesive layer 29 is formed around the base portion 42, and the base portion 42 of the vibrating piece 40 is fixed to the second housing 20.

  In addition, when the base 42 is fixed with an adhesive, the adhesive may come into contact with the measurement target. In such a case, the adhesive may deteriorate depending on the object to be measured. As a method for avoiding this, as shown in FIG. 10, a modification of fixing the base 42 without using an adhesive is possible. For example, as shown in FIG. 10, a packing 60 can be formed on the surface of the base portion 42 so as to surround the base portion 42, and can be joined to the second housing 20 by a brazing material layer 68. Examples of the material of the packing 60 include Cr, Ni, Pa, and Au. Examples of the material of the brazing material layer 68 include a solder material such as Au / Sn. In the illustrated example, the packing 60 has a structure in which a Cr layer 62, a Pa layer 64, and an Au layer 66 are laminated from the surface side of the base portion. The Pa layer 64 may contain Ni or may be a Ni layer. The Cr layer 62, the Pa layer 64, and the Au layer 66 can be formed by sputtering, vapor deposition, plating, or the like so as to have thicknesses of 100, 3000 to 5000, and 5 to 10 μm, respectively, and are appropriately patterned. be able to. In the example of FIG. 10, the base 42 is drawn so as to penetrate and join the second housing 20, but the packing 60 can be regarded as the second housing. Therefore, in the example of FIG. 10, it may be understood that the base 42 penetrates through the second housing (packing 60).

  The above-described modification is different from the viscosity sensor described in the section of “1. Viscosity sensor” in that some aspects of the members are different, and the operation of the viscosity sensor and the detection of the viscosity are described in “2. This is the same as described in “Detection of viscosity and operation of viscosity sensor”.

  The modifications exemplified above can be freely applied to the viscosity sensor of this embodiment individually or in combination with each other.

4). Viscosity Measuring Method A viscosity measuring method according to this embodiment includes a base 42 and an arm 44 extending from the base 42, and uses a vibrating piece 40 whose impedance changes when the vibration of the base 42 changes. A measurement method, a step of inputting a drive signal to the arm portion 44 of the resonator element 40 to vibrate the arm portion 44 and the base portion 42; a step of bringing the base portion 42 into direct or indirect contact with a measurement object; Detecting a change in vibration as a change in impedance of the resonator element 40.

  In this measurement method, as the vibrating piece 40 having the base portion 42 and the arm portion 44 extending from the base portion 42 and whose impedance changes when the vibration of the base portion 42 changes, the vibrating piece 40 included in the above-described viscosity sensor is given. be able to. Therefore, in this measurement method, the viscosity sensor described in the section “1. Viscosity sensor” or a viscosity sensor in which the deformation described in “3. Modifications” is freely combined can be used.

  Therefore, the step of vibrating the arm portion 44 and the base portion 42 and the step of detecting a change in the vibration of the base portion 42 in this measurement method are described in the above section “2. Detection of viscosity by the viscosity sensor and operation of the viscosity sensor”. As stated.

  In the step of bringing the base part 42 into direct or indirect contact with the measurement object, for example, the base part 42 can be brought into direct contact with the measurement object by using a viscosity sensor provided through the second housing 20. . Further, in the step of bringing the base portion 42 into direct or indirect contact with the measurement object, a viscosity sensor provided without the base portion 42 penetrating through the second housing 20 is used, so that the base portion 42 is set as the measurement object via the second housing 20. Can be contacted indirectly.

  According to the viscosity measurement method of the present embodiment, the viscosity of a wide range of substances including liquid can be easily measured. In other words, the viscosity of the measurement target can be measured using leakage vibration derived from the vibration of the arm portion 44. Therefore, even when the vibration of the base 42 is suppressed when measuring the viscosity of a liquid having a very high viscosity or a viscoelastic body, the vibrating piece 40 can continue to oscillate without being stopped.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and effects). In addition, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

10 ... 1st housing, 12 ... Terminal, 20 ... 2nd housing,
22, 28, 29 ... adhesive layer, 30 ... isolator, 32 ... sealed space,
40, 41 ... vibrating piece, 42 ... base, 43 ... wiring branch, 44 ... arm, 46 ... electrode,
48 ... wiring, 49 ... weight, 50 ... bonding wire, 60 ... packing,
62 ... Cr layer, 64 ... Pa layer, 66 ... Au layer, 68 ... brazing material layer,
100, 300, 400 ... viscosity sensor, 102 ... output signal, 200 ... oscillation circuit,
212 ... Amplifier, 214 ... Feedback resistor, 222 ... Drain resistor,
224,226 ... Condenser

Claims (8)

A first housing;
A second housing;
An isolator for connecting the first housing and the second housing to form a sealed space, and isolating vibration propagation between the first housing and the second housing;
A vibrating piece having a base portion housed in the sealed space and fixed to the second housing and an arm portion extending from the base portion;
Including
A viscosity sensor in which vibration of the arm portion of the vibrating piece leaks to the base and the second housing. In claim 1,
The vibrating piece includes an electrode formed on the arm portion, and a wiring formed on the base portion and electrically connected to the electrode,
The first housing has a terminal for electrical connection from the outside to the inside,
The wiring is a viscosity sensor electrically connected to the terminal in the sealed space. In claim 1 or claim 2,
The vibration piece is a tuning fork type vibration piece, a viscosity sensor. In any one of Claims 1 to 3,
The base of the vibration piece is a viscosity sensor that penetrates the second housing. In any one of Claims 1 to 3,
A viscosity sensor, wherein a contact piece is further provided outside the position where the base portion of the second housing is fixed. In any one of Claims 1 thru | or 4,
The vibration piece is a viscosity sensor in which impedance changes in response to a change in magnitude of vibration of the base when at least one of the base and the second housing is in contact with a measurement target. In claim 5,
The contact piece vibrates due to leakage vibration leaking from the arm portion,
The vibration piece is a viscosity sensor in which an impedance changes in response to a change in magnitude of vibration of the base portion when at least one of the contact piece and the second housing comes into contact with a measurement target. A viscosity measuring method using a vibrating piece having a base and an arm extending from the base, the impedance of which changes when the vibration of the base changes,
Inputting a drive signal to the arm portion of the vibrating piece to vibrate the arm portion and the base portion;
Contacting the base directly or indirectly with a measurement object;
Detecting a change in vibration of the base as a change in impedance of the vibrating piece;
Viscosity measurement method including

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