Property determination system and property determination method

Abstract

To provide a property determination system capable of determining the property of liquid to be measured with high accuracy.SOLUTION: A property determination system for determining the property of liquid to be measured includes a heating part 10 for locally heating the liquid to be measured, a temperature measurement part 20 for measuring the temperature of the liquid to be measured in the vicinity of the heating part 10, and an information processing part 30 that can determine the property of the liquid to be measured on the basis of temperature measurement data acquired by temperature measurement by the temperature measurement part 20, and the information processing part 30 determines the property of the liquid to be measured on the basis of temperature measurement data after first sampling time T1 being a time point when prescribed time t1 passes from heating start time T0 when the heating part 10 starts heating in the temperature measurement data.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a property determination system for determining the properties of a liquid to be measured. The present invention also relates to a method for determining the properties of a liquid to be measured using this property determination system.

Background Art

[0002] For liquids such as lubricating oil and fuel (liquids to be measured), properties such as kinematic viscosity, degree of deterioration, type, and distillation properties are determined. For example, Patent Document 1 describes a light oil liquid type identification device for identifying the type and distillation properties of light oil.

[0003] As shown in FIG. 3 of the same document, the liquid type identification device described in Patent Document 1 includes a liquid type identification sensor 24 having a liquid type identification sensor heater 25 and a liquid temperature sensor 28. As shown in FIG. 4 of the same document, the liquid type identification sensor heater 25 is integrally formed by a molding resin 30 with a lead electrode 32, a thin film chip portion 34, and a metal fin 36 protruding into the light oil liquid type identification chamber 20 and directly contacting the light oil to be identified. The lead electrode 32, the thin film chip portion 34, and the fin 36 are electrically connected to each other by a bonding wire 38. As shown in FIG. 5 of the same document, the thin film chip portion 34 is composed of a thin film chip in which a substrate 40, a temperature sensor (temperature-sensitive body) 42, an interlayer insulating film 44, a heater (heating element) 46, a heater electrode 48, a protective film 50, and an electrode pad 52 are laminated in this order.

[0004] In the liquid type identification device of Patent Document 1, as described in FIGS. 7 and paragraphs 0064 to 0071 of the same document, a pulse voltage P is applied to the heater 46 of the liquid type identification sensor heater 25 for 10 seconds, and a voltage difference V0 = V2 - V1 is obtained from the voltage V1 of the liquid temperature sensor 28 immediately before the voltage application and the peak voltage V2 of the liquid temperature sensor 28 after the voltage application. And it is said that it is possible to recognize the liquid type identification and distillation properties of light oil based on the value of this voltage difference V0 and the data previously stored in the computer 72.

Prior Art Documents

Patent Document

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, as can be read from FIG. 9 and the like of Patent Document 1, the liquid type identification device of Patent Document 1 had room for improvement in accuracy.

[0007] The present invention has been made to solve the above problems, and provides a property determination system capable of determining the properties of a liquid to be measured with high accuracy. It is also an object of the present invention to provide a method for determining the properties of a liquid to be measured using this property determination system.

Means for Solving the Problems

[0008] The above problems are a property determination system for determining the properties of a liquid to be measured, a heating unit for locally heating the liquid to be measured, a temperature measurement unit for measuring the temperature of the liquid to be measured in the vicinity of the heating unit, and an information processing unit capable of determining the properties of the liquid to be measured based on the temperature measurement data obtained by the temperature measurement unit and is provided with The information processing unit determines the properties of the liquid to be measured based on the temperature measurement data after the first sampling time T 0 which is the time when a predetermined time t 1 has elapsed since the heating start time T 1 when the heating unit starts heating. Property determination system is solved by providing.

[0009] In the above property determination system, among the temperature measurement data, at the first sampling time T1 By determining the properties of the liquid to be measured based on the subsequent temperature measurement data, the properties of the liquid to be measured can be determined with high accuracy. The reason for this will be described in detail later.

[0010] As the properties of the liquid to be measured determined in the above property determination system, for example, the kinematic viscosity, degree of deterioration, or degree of impurity contamination of the liquid to be measured can be adopted.

[0011] In the above property determination system, the information processing unit is set to the value D of the temperature measurement data at the first sampling time T 1 and the value D of the temperature measurement data at the second sampling time T 1 which is the time point when a predetermined time t 0 longer than a predetermined time t 1 has elapsed since the start of heating at T 2 Based on the difference ΔD 2 between them, the properties of the liquid to be measured can be determined. 2 12 12 Based on the difference ΔD

[0012] In the above property determination system, the information processing unit can be made to switch between a plurality of modes with different timings at the first sampling time T 1 In this case, the information processing unit determines which of the plurality of modes to use based on the temperature measurement data after the mode determination first sampling time T 0 which is the time point when a predetermined time t P has elapsed since the start of heating in the temperature measurement data. P Based on the temperature measurement data after the mode determination first sampling time T

[0013] The above property determination system is not limited to the apparatus or location to which it is applied. In the above property determination system, for example, the heating unit and the temperature measurement unit can be provided inside the storage tank of the liquid to be measured or inside the flow path of the liquid to be measured.

Advantages of the Invention

[0014] As described above, the present invention makes it possible to provide a property determination system that can determine the properties of a liquid to be measured with high accuracy. Further, it is also possible to provide a method for determining the properties of a liquid to be measured using this property determination system.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0016] 1. First Embodiment A preferred embodiment of the present invention will be described more specifically with reference to the drawings. FIG. 1 is a block diagram of the property determination system according to the first embodiment. FIG. 2 is a diagram schematically showing the structure of the sensor chip 40 in the property determination system according to the first embodiment. FIG. 2(a) is a front view of the sensor chip 40, and FIG. 2(b) is a cross-sectional view showing the sensor chip 40 of FIG. 2(a) cut along the A-A plane. In FIG. 2 and FIGS. 4 and 5 described later, the x-axis, y-axis, and z-axis are shown, and these axes are made to coincide even between different drawings. In the present embodiment, the positive side of the z-axis coincides with the upper side in the vertical direction, and the negative side of the z-axis coincides with the lower side in the vertical direction. However, this does not immediately limit the orientation of the sensor chip 40 in the present invention.

[0017] The property determination system according to the first embodiment is for determining the property of the liquid to be measured. Specifically, it is for determining the kinematic viscosity of the lubricating oil (liquid to be measured) stored in a tank (not shown). Thereby, for example, it is possible to monitor whether the kinematic viscosity of the lubricating oil (liquid to be measured) is within an appropriate range.

[0018] As shown in FIG. 1, this property determination system includes a heating unit 10, a temperature measurement unit 20, and an information processing unit 30. The heating unit 10 and the temperature measurement unit 20 are usually used in a state of being immersed in the liquid to be measured. The heating unit 10 is a part for locally heating the liquid to be measured (lubricating oil). The temperature measurement unit 20 is a part for measuring the temperature of the liquid to be measured in the vicinity of the heating unit 10. The information processing unit 30 is a part for performing electronic information processing.

[0019] The heating unit 10 and the temperature measuring unit 20 can be provided on separate members from each other. However, in the present embodiment, as shown in FIG. 2, the heating unit 10 and the temperature measuring unit 20 in the present embodiment are provided on the same sensor chip 40. As shown in FIG. 2(b), this sensor chip 40 includes a base portion 41, a substrate 42 fixed to the base portion 41, a temperature measuring unit 20 formed on the substrate 42, and a heating unit 10 laminated on the surface layer side of the temperature measuring unit 20. An insulating film 43 is laminated between the temperature measuring unit 20 and the heating unit 10, and a protective film 44 is laminated on the surface layer side of the heating unit 10. The heating unit 10 in the present embodiment can locally heat the liquid to be measured in its vicinity by generating heat in response to the applied voltage. The temperature measuring unit 20 outputs an output value (output voltage Vf in the present embodiment) corresponding to the measured temperature.

[0020] As shown by the double-headed arrow in FIG. 1, the information processing unit 30 can exchange signals and data with the heating unit 10 and the temperature measuring unit 20. The exchange of signals and data may be wired communication or wireless communication. As the information processing unit 30, for example, a microcomputer, a personal computer, or the like can be used. As long as the information processing unit 30 can exchange signals and data with the heating unit 10 and the temperature measuring unit 20, its installation location is not limited, and it can be installed at a location physically close to the heating unit 10 and the temperature measuring unit 20, or at a physically distant location.

[0021] As shown in FIG. 1, the information processing unit 30 in the first embodiment includes a control means 31 for controlling the heating unit 10, a data acquisition means 32 for acquiring temperature measurement data obtained by temperature measurement by the temperature measuring unit 20, a property determination means 33 for determining the property of the liquid to be measured based on the temperature measurement data acquired by the data acquisition means 32, and a storage means 34 for storing various information. Each means included in the information processing unit 30 may be provided in one information processing device, or may be divided and provided in a plurality of different information processing devices.

[0022] Hereinafter, taking the case of determining the kinematic viscosity of the liquid to be measured using the property determination system of the first embodiment as an example, the processing by the property determination system will be described. First, with the heating unit 10 and the temperature measurement unit 20 (sensor chip 40) immersed in the liquid to be measured, the control means 31 starts heating the heating unit 10. The time point when this heating is started is defined as the start of heating T 0 Let it be. The heating unit 10 continuously heats with a constant output, and when it reaches the end of heating T 0 after a predetermined time t E has elapsed from the start of heating T E , the heating is terminated.

[0023] The temperature measurement unit 20 measures the temperature of the liquid to be measured in the vicinity of the heating unit 10 over time from the start of heating T 0 (or a point in time before that) until the end of heating T E (or a point in time after that). The output of the temperature measurement unit 20 (output voltage Vf in this embodiment) is output to the information processing unit 30.

[0024] The data acquisition means 32 of the information processing unit 30 acquires the temperature measurement data obtained by the temperature measurement of the temperature measurement unit 20. FIG. 3 is a diagram showing an example of the temperature measurement data. The horizontal axis in FIG. 3 represents time, and the vertical axis represents the output voltage Vf of the temperature measurement unit 20. In this embodiment, the output voltage Vf, which is the output value of the temperature measurement unit 20 itself, is used as the temperature measurement data. However, the type of the temperature measurement data is not limited as long as it reflects the temperature measured by the temperature measurement unit 20. For example, it may be temperature data obtained based on the output value of the temperature measurement unit 20. The temperature measurement data (output voltage Vf) in this embodiment increases at a relatively fast rate immediately after the start of heating T 0 , but as time passes, the rate of increase becomes slower and approaches a steady state.

[0025] Subsequently, the property determination means 33 determines the property (kinematic viscosity) of the liquid to be measured based on the temperature measurement data acquired by the data acquisition means 32. At this time, the property determination means 33 is from the start of heating T 0 to a predetermined time t 1 (0 < t 1<t E is the first sampling time T when E has elapsed 1 Based on the temperature measurement data after (Fig. 3), the kinematic viscosity of the liquid to be measured is determined. In other words, the temperature measurement data before the first sampling time T 1 is not used for the determination of the kinematic viscosity by the property determination means 33. Thereby, the determination accuracy can be improved. The reason for this will be described in detail later.

[0026] As a method for the property determination means 33 to determine the kinematic viscosity of the liquid to be measured based on the temperature measurement data after the first sampling time T 1 various processing methods can be adopted. For example, the property determination means 33 can determine the kinematic viscosity of the liquid to be measured by fitting a function pre-stored in the storage means 34 to the temperature measurement data over time (or a plurality of data points in the temperature measurement data) after the first sampling time T 1 However, in this case, the information processing process by the property determination means 33 becomes complicated, and it is necessary to increase the specifications of the information processing unit 30.

[0027] In this regard, in the present embodiment, a second sampling time T 0 is defined as the time when a predetermined time t 2 (t 1 <t 2 ≦t E ) has elapsed since the start time T of heating, and the property determination means 33 determines the kinematic viscosity of the liquid to be measured based on the difference ΔD 2 between the value D 1 of the temperature measurement data at the first sampling time T 1 and the value D 2 of the temperature measurement data at the second sampling time T 2 . More specifically, the property determination means 33 determines the value of the kinematic viscosity by substituting the difference ΔD 12 into a conversion formula for property determination pre-stored in the storage means 34. In another embodiment, the property determination means 33 uses a table for property determination pre-stored in the storage means 34 and the difference ΔD 12 to determine the kinematic viscosity. In another embodiment, the property determination means 33 uses a table for property determination pre-stored in the storage means 34 and the difference ΔD 12The properties of the liquid to be measured can also be determined by, for example, comparing them with something.

[0028] The conversion formula for property determination is not limited to its specific function. As the conversion formula for property determination, for example, quadratic functions, linear functions, cubic functions, logarithmic functions, exponential functions, etc. can be used. The conversion formula for property determination can also be one in which either or both of the differential ΔD 12 and the kinematic viscosity are on a logarithmic scale. However, in this case, the information processing in the property determination means 33 may become complicated. Therefore, as the conversion formula for property determination in this embodiment, the differential ΔD 12 and the kinematic viscosity both use a linear scale.

[0029] In this way, by determining the kinematic viscosity based on the differential ΔD 12 the information processing process by the property determination means 33 can be simplified. In the first embodiment, for the lengths of the predetermined time t 1 the predetermined time t 2 and the predetermined time t E (the timings at the first sampling time T 1 the second sampling time T 2 and the end of heating time T E ), the values stored in the storage means 34 in advance are used. Thus, the determination of the kinematic viscosity of the liquid to be measured using the property determination system of the first embodiment is completed.

[0030] FIG. 4 is a diagram for explaining the movement of the liquid to be measured in the vicinity of the heating unit 10 when heating is performed by the heating unit 10. FIG. 4(a) shows the state immediately after the start of heating, FIG. 4(b) shows the state after a certain period of time has elapsed since the start of heating, and FIG. 4(c) shows the state after further heating continues from the state of FIG. 4(b).

[0031] Hereinafter, the reason why the kinematic viscosity of the liquid to be measured can be determined with high accuracy by using the property determination system of the first embodiment will be described with reference to FIG. 4. At the start of heating T 0When the heating by the heating unit 10 starts, as shown in FIG. 3, the temperature of the liquid to be measured in the vicinity of the heating unit 10 begins to rise. At this stage, as shown in FIG. 4(a), only heat is transferred from the heating unit 10 to the heated portion of the liquid to be measured (shown by hatched hatching in the figure) and to other portions of the sensor chip 40, and hardly any movement of the liquid to be measured (due to heating) occurs. That is, the change in the temperature of the liquid to be measured in the vicinity of the heating unit 10 (temperature measurement data obtained from the temperature measurement unit 20) at this stage mainly reflects the heat conduction from the heating unit 10 to the liquid to be measured and the sensor chip 40.

[0032] If the heating is continued as it is, the specific gravity of the heated portion of the liquid to be measured decreases, and as shown by the arrow α in FIG. 4(b), this portion begins to float upward in the vertical direction. As a result, as shown by the arrow β in the figure, the unheated liquid to be measured is supplied to the portion from which the heated liquid to be measured has left, and the liquid to be measured close to the heating unit 10 is replaced by natural convection. When this stage is reached, the change in the temperature of the liquid to be measured in the vicinity of the heating unit 10 (temperature measurement data obtained from the temperature measurement unit 20) comes to reflect the kinematic viscosity of the liquid to be measured. If the heating is continued further, as shown in FIG. 4(c), a steady state is reached eventually. When this stage is reached, the temperature of the liquid to be measured in the vicinity of the heating unit 10 (temperature measurement data obtained from the temperature measurement unit 20) hardly changes.

[0033] As described above, the temperature measurement data in the time period from when the heating unit 10 starts heating until the liquid to be measured starts to convect mainly reflects heat conduction and hardly reflects the kinematic viscosity of the liquid to be measured. Therefore, when determining the kinematic viscosity, including the temperature measurement data of this portion makes it difficult to improve the determination accuracy. In this regard, in the present embodiment, the temperature measurement data from the start of heating T 0 to the first sampling time T 1 (that is, the temperature measurement data at the initial stage of heating start) is not used for the determination, and the kinematic viscosity is determined based on the temperature measurement data after the first sampling time T 1 . For this reason, the noise due to the influence of heat conduction can be reduced, and the determination accuracy of the kinematic viscosity can be improved.

[0034] Thus, at the first sampling time T 1 By determining the properties of the liquid to be measured based on the temperature measurement data after that, the properties of the liquid to be measured can be determined with high accuracy. In addition, by adopting such a method, since the error due to the difference in thermal conductivity between different liquids to be measured can be reduced, as shown in Experimental Example 1 below, the conversion formula for property determination obtained based on one reference liquid can also be applied to other types of liquids to be measured. In other words, the kinematic viscosity of a plurality of types of liquids to be measured can be determined by one conversion formula for property determination. Therefore, it is not necessary to prepare a conversion formula for property determination for each liquid to be measured, and the configuration and processing of the property determination system can be made simple.

[0035] At the start of heating T 0 to the first sampling time T 1 The length of the time (predetermined time t 1 ) up to is different depending on the configurations of the heating unit 10 and the temperature measurement unit 20 and is not limited. However, if the predetermined time t 1 is too short, the influence of the above-described heat conduction becomes too large, and there is a possibility that it becomes difficult to improve the determination accuracy. On the other hand, if the predetermined time t 1 is too long, the natural convection of the liquid to be measured heated by the heating unit 10 reaches a steady state, and there is also a possibility that it becomes difficult to improve the determination accuracy. For this reason, the length of the predetermined time t 1 is usually set to 1 second or more and 20 seconds or less. The length of the predetermined time t 1 is preferably 1.5 seconds or more and 10 seconds or less. The length of the predetermined time t 1 in the present embodiment is 3 seconds.

[0036] In the steady state shown in FIG. 4(c), the temperature of the liquid to be measured in the vicinity of the heating unit 10 (temperature measurement data obtained from the temperature measurement unit 20) has a strong correlation with the kinematic viscosity of the liquid to be measured. Therefore, the second sampling time T 12 for taking the difference ΔD 2It is preferably set at the time point in a state close to FIG. 4(c). Thereby, the determination accuracy of the kinematic viscosity can be further enhanced. Heating start time T 0 to the second sampling time T 2 The length of the time (predetermined time t 2 ) up to is not limited, but if it is too short, it becomes difficult to reflect the state in which the natural convection of the liquid to be measured has reached a steady state, and there is a possibility that it becomes difficult to enhance the determination accuracy. If it is too long, the time required for determination becomes uselessly long. For this reason, the length of the predetermined time t 2 is usually set to 5 seconds or more and 100 seconds or less. The length of the predetermined time t 2 is preferably 10 seconds or more and 60 seconds or less. The length of the predetermined time t 2 in this embodiment is 30 seconds.

[0037] In the first embodiment, the heating unit 10 and the temperature measuring unit 20 were laminated on a single sensor chip 40 as shown in FIG. 2. In this case, the distance between the heating unit 10 and the temperature measuring unit 20 is preferably about 0.5 μm to 10 μm, and more preferably about 1 to 3 μm. However, the temperature measuring unit 20 only needs to be able to capture the temperature change of the liquid to be measured heated by the heating unit 10, and the relative positional relationship with the heating unit 10 is not limited.

[0038] FIG. 5 is a diagram showing another structural example of the heating unit 10 and the temperature measuring unit 20. As described above, the liquid to be measured heated by the heating unit 10 floats upward in the vertical direction. Therefore, in another embodiment, for example, as shown in FIG. 5(a), the temperature measuring unit 20 and the heating unit 10 can be provided side by side with the temperature measuring unit 20 arranged above the heating unit 10 in the vertical direction. In FIG. 5(a), the temperature measuring unit 20 and the heating unit 10 are provided on a single sensor chip 40, but the temperature measuring unit 20 and the heating unit 10 may be provided on separate sensor chips. However, if the temperature measuring unit 20 and the heating unit 10 are too far apart, the liquid to be measured heated by the heating unit 10 will diffuse, making it difficult to capture the temperature change of the liquid to be measured. For this reason, in this case, the distance between the temperature measuring unit 20 and the heating unit 10 is preferably 5 mm or less, more preferably 3 mm or less, and even more preferably 1 mm or less. The lower limit of the distance between the temperature measuring unit 20 and the heating unit 10 is not limited, but is usually 0.1 mm or more.

[0039] In still another embodiment, as shown in FIG. 5(b), the heating unit 10 can be formed in a coil shape instead of a thin film, and the temperature measuring unit 20 can be arranged inside the coil. In this case, the distance between the temperature measuring unit 20 and the heating unit 10 is preferably 5 mm or less, and more preferably 1 mm or less. The lower limit of the distance between the temperature measuring unit 20 and the heating unit 10 is not limited, but is usually 0.1 mm or more.

[0040] As described above, the property determination system of the first embodiment is for determining the kinematic viscosity of the liquid to be measured. However, the property of the liquid to be measured to be determined using the property determination system (hereinafter, may be expressed as "determination target property") is not particularly limited as long as it correlates with the thermal property of the liquid to be measured. The determination target property may be a generally used physical quantity or an item unique to the property determination system. Examples of the determination target property include kinematic viscosity, degree of deterioration, degree of impurity contamination, type (liquid type), distillation property, mixing ratio in the case where the liquid to be measured is a mixture of two or more liquids, or a property that can be determined based on these properties. In the property determination system of the present embodiment, the kinematic viscosity is the determination target property.

[0041] The specific type of the liquid to be measured is not particularly limited. The liquid to be measured is preferably a liquid mainly composed of non-polar molecules (for example, a liquid in which the proportion of non-polar molecules is 90% by weight or more). Examples of the liquid to be measured include industrial oils and fuels. Examples of industrial oils include lubricating oils such as engine oil, hydraulic oil, gear oil, machine oil, turbine oil, compressor oil, spindle oil, dynamo oil, cylinder oil, bearing oil, refrigeration oil, pump oil, cutting oil, heat treatment oil, rust preventive oil, and cleaning oil. Examples of fuels include gasoline, light oil, kerosene, heavy oil, biodiesel, HVO, synthetic fuel, etc.

[0042] The property determination system is not limited as long as it is used to determine the property of the liquid to be measured. Examples of the device to which this is applied (hereinafter, may be expressed as "application target device") include automobiles, airplanes, ships, trains, machines, factory equipment, etc.

[0043] The property determination system can determine the properties without sampling (such as dispensing) the liquid to be measured, and has the characteristic that it does not change the composition of the liquid to be measured before and after the determination. Therefore, the property determination system can be suitably used for the purpose of directly determining the properties of the liquid to be measured actually used in the target device in-line. In this case, for example, it is also possible to separately provide a chamber for property determination (a chamber for immersing the heating unit 10 and the temperature measuring unit 20 in the liquid to be measured) branched from the main line of the liquid to be measured in the target device. However, if a chamber for property determination is to be provided, there is a risk that the restrictions imposed on the design of the target device will increase. For this reason, it is preferable to provide the heating unit 10 and the temperature measuring unit 20 in the storage tank of the liquid to be measured provided in the target device or in the flow path of the liquid to be measured. Thereby, the restrictions imposed on the design of the target device can be reduced.

[0044] As shown in FIG. 3, the data acquisition means 32 in the first embodiment acquires the temperature measurement data over time from the start time T of heating 0 (or a time point before that) until the end time T of heating E (or a time point after that). However, the data acquisition means 32 may acquire only the value of the temperature measurement data at a specific time point. That is, the data acquisition means 32 may acquire, for example, the value D of the temperature measurement data at the first sampling time T 1 and the value D of the temperature measurement data at the second sampling time T 1 . Alternatively, the data acquisition means 32 may intermittently acquire the temperature measurement data in a state including the first sampling time T 2 and the second sampling time T 2 . 1 and the second sampling time T 2 .

[0045] 2. Second Embodiment FIG. 6 is a block diagram of the information processing unit 30 in the property determination system of the second embodiment. FIG. 7 is a diagram showing examples of temperature measurement data obtained from the liquid to be measured with low kinematic viscosity, medium kinematic viscosity, and high kinematic viscosity, respectively. FIG. 7(a) shows the temperature measurement data obtained from the liquid to be measured with low kinematic viscosity, FIG. 7(b) shows the temperature measurement data obtained from the liquid to be measured with medium kinematic viscosity, and FIG. 7(c) shows the temperature measurement data obtained from the liquid to be measured with high kinematic viscosity.

[0046] Next, the property determination system of the second embodiment will be described. Similar to the property determination system of the first embodiment, the property determination system of the second embodiment is also for determining the kinematic viscosity of the lubricating oil (liquid to be measured). In the following, mainly, the parts different from the property determination system of the first embodiment in the property determination system of the second embodiment will be described. For other parts, the same configuration as that of the property determination system of the first embodiment can be adopted in the property determination system of the second embodiment.

[0047] As shown in FIG. 6, the information processing unit 30 in the property determination system of the second embodiment includes a control unit 31, a data acquisition unit 32, a property determination unit 33, a storage unit 34, and a mode determination unit 35. The information processing unit 30 in the second embodiment can switch between a plurality of modes with different timings at the first sampling time T 1 . Specifically, it can switch between a low kinematic viscosity mode suitable for determining the liquid to be measured with low kinematic viscosity, a medium kinematic viscosity mode suitable for determining the liquid to be measured with medium kinematic viscosity, and a high kinematic viscosity mode suitable for determining the liquid to be measured with high kinematic viscosity. The mode determination unit 35 is a means for determining which of these modes to use.

[0048] Hereinafter, the process for determining the kinematic viscosity of the liquid to be measured using the property determination system of the second embodiment will be described. For the heating by the heating unit 10, the temperature measurement by the temperature measurement unit 20, and the acquisition of the temperature measurement data by the data acquisition unit 32, the same processes as those described in the first embodiment can be adopted.

[0049] In the second embodiment, when the data acquisition means 32 acquires the temperature measurement data, first, the mode determination means 35 determines the mode. The mode determination means 35 is not limited to the criteria for determining the mode. For example, the mode can be determined based on the temperature at the start of heating T 0 (the output value of the temperature measurement unit 20), etc. Alternatively, the mode can be determined based on an artificial selection by the user. The mode determination means 35 in the present embodiment is based on the temperature measurement data after the first sampling time T 0 for mode determination, which is the time point when a predetermined time t P has elapsed since the start of heating T P (Fig. 7). In other words, the temperature measurement data before the first sampling time T P for mode determination is not used for the mode determination by the mode determination means 35. Thereby, an appropriate mode can be selected with high accuracy according to the kinematic viscosity of the liquid to be measured.

[0050] The length of the time (predetermined time t 0 ) from the start of heating T P to the first sampling time T P for mode determination is not limited. The length of the predetermined time t P is usually 1 second or more and 20 seconds or less, and preferably 1.5 seconds or more and 10 seconds or less. In the present embodiment, the predetermined time t P is set to 3 seconds.

[0051] In the present embodiment, the second sampling time T 0 for mode determination, which is the time point when a predetermined time t Q (t P <t Q ) has elapsed since the start of heating, is defined. And the mode determination means 35 is the value D Q of the temperature measurement data at the first sampling time T P for mode determination (not shown), and the value D P of the temperature measurement data at the second sampling time T Q for mode determination Q(not shown) and the difference ΔD PQ More specifically, the mode determination means 35 determines the mode based on the difference ΔD PQ The mode is determined based on a comparison result between the difference ΔD and a mode determining reference difference previously stored in the storage means 34. That is, the storage means 34 stores a low kinetic viscosity side reference difference for determining whether to use the low kinetic viscosity mode or the medium kinetic viscosity mode, and a high kinetic viscosity side reference difference for determining whether to use the medium kinetic viscosity mode or the high kinetic viscosity mode. PQ If is smaller than the low kinematic viscosity side reference difference, select the low kinematic viscosity mode, and the difference ΔD PQ If the difference is between the low viscosity side standard difference and the high viscosity side standard difference, select the medium viscosity mode, and the difference ΔD PQ If is greater than the high kinetic viscosity side reference difference, the high kinetic viscosity mode is selected.

[0052] T at the start of heating 0 From the second sampling time for mode determination T Q Time until (predetermined time t Q The length of the predetermined time t Q The length of the predetermined time t is usually 5 seconds or more and 100 seconds or less, preferably 7 seconds or more and 60 seconds or less, and more preferably 10 seconds or more and 30 seconds or less. Q The time is set to about 15 seconds.

[0053] As another method, the mode determination means 35 may determine the heating start time T 0 From a given time t R The third sampling time for mode determination, T R (not shown) is defined, and the third sampling time for mode determination T R Rate of increase in temperature data (rate of temperature rise) I R That is, the storage means 34 stores a low kinetic viscosity side reference increase rate for determining whether to use the low kinetic viscosity mode or the medium kinetic viscosity mode, and a high kinetic viscosity side reference increase rate for determining whether to use the medium kinetic viscosity mode or the high kinetic viscosity mode, and the mode determination means 35 stores the increase rate IR If it is smaller than the low kinematic viscosity side reference increase rate, select the low kinematic viscosity mode, and the increase rate I R If it is between the low kinematic viscosity side reference increase rate and the high kinematic viscosity side reference increase rate, select the medium kinematic viscosity mode, and the increase rate I R If it is larger than the high kinematic viscosity side reference increase rate, select the high kinematic viscosity mode.

[0054] At the start of heating T 0 to the time at the third sampling for mode determination T R The length of up to (predetermined time t R ) is not limited. The length of the predetermined time t R is preferably 3 seconds or more and 30 seconds or less, and more preferably 5 seconds or more and 15 seconds or less.

[0055] When the mode is determined by the mode determination means 35, in the selected mode, the property determination means 33 determines the kinematic viscosity of the liquid to be measured. The plurality of modes in this embodiment are at the timing at the first sampling T 1 The timing (length of the predetermined time t 1 ) and the timing at the second sampling T 2 The timing (length of the predetermined time t 2 ) are different from each other. That is, as shown in FIG. 7, the predetermined time t 1 and the predetermined time t 2 in the low kinematic viscosity mode are respectively shorter than the predetermined time t 1 and the predetermined time t 2 in the medium kinematic viscosity mode, and the predetermined time t 1 and the predetermined time t 2 in the high kinematic viscosity mode are respectively longer than the predetermined time t 1 and the predetermined time t 2 in the medium kinematic viscosity mode. Thereby, the differential ΔD 12 can be obtained within an appropriate range according to the degree of the kinematic viscosity of the liquid to be measured.

[0056] The reason for this is as follows. That is, as shown in FIG. 7(a), the liquid to be measured with a low kinematic viscosity reaches a steady state in a short time. Therefore, at the first sampling time T of the medium kinematic viscosity mode1 At this point, the temperature measurement data obtained from the temperature measurement unit 20 has already significantly decayed. Therefore, at the first sampling time T 1 in the medium kinematic viscosity mode and the first sampling time T 2 if a difference ΔD 12 is to be taken, the difference ΔD 12 becomes too small, making it difficult to improve the determination accuracy. In this regard, in the low kinematic viscosity mode, the first sampling time T 1 and the first sampling time T 2 set earlier than in the medium kinematic viscosity mode are used to take the difference ΔD 12 , thus solving the above problem.

[0057] Also, as shown in FIG. 7(c), the high kinematic viscosity liquid to be measured takes a long time to reach a steady state. For this reason, at the first sampling time T 2 in the medium kinematic viscosity mode, the temperature measurement data obtained from the temperature measurement unit 20 has not reached a steady state. Therefore, at the first sampling time T 1 in the medium kinematic viscosity mode and the first sampling time T 2 if a difference ΔD 12 is to be taken, the value of the difference ΔD 12 may be less likely to reflect the kinematic viscosity. In this regard, in the high kinematic viscosity mode, the first sampling time T 1 and the first sampling time T 2 set later than in the medium kinematic viscosity mode are used to take the difference ΔD 12 , thus solving the above problem.

[0058] The lengths of the predetermined times t 1 and the predetermined times t 2 in each mode are not limited. However, in this embodiment, the predetermined times t 1 and the predetermined times t 2 in the low kinematic viscosity mode are about 2 seconds and about 11 seconds respectively, and the predetermined times t 1 and the predetermined times t 2 in the medium kinematic viscosity mode are about 3 seconds and about 15 seconds respectively, and the predetermined times t 1and a predetermined time t 2 are set to about 5 seconds and about 30 seconds, respectively.

[0059] The property determination means 33 substitutes the difference ΔD into the conversion formula for property determination stored in advance in the storage means 34, 12 or compares the difference ΔD with the property determination table stored in advance in the storage means 34 12 to determine the property (kinematic viscosity) of the liquid to be measured. At this time, the property determination means 33 can use the same conversion formula for property determination or property determination table in any mode. However, in this case, there is a possibility that it becomes difficult to improve the determination accuracy. For this reason, in the present embodiment, a conversion formula for property determination (or a property determination table) for the low kinematic viscosity mode, a conversion formula for property determination (or a property determination table) for the medium kinematic viscosity mode, and a conversion formula for property determination (or a property determination table) for the high and low kinematic viscosity modes are stored in advance in the storage means 34, respectively, and the conversion formula for property determination corresponding to the mode is used. Thereby, the determination accuracy can be further improved.

[0060] In this way, by switching the mode of the information processing unit 30 according to the kinematic viscosity of the liquid to be measured, as shown in Experimental Example 2 described later, the kinematic viscosity determination accuracy of the liquid to be measured can be improved in a wide kinematic viscosity range. In the second embodiment, the information processing unit 30 has three types of modes, but the number of modes of the information processing unit 30 is not particularly limited. From the viewpoint of improving the determination accuracy, the number of modes is preferably 2 or more, and more preferably 3 or more. However, if the number of modes is too large, only the information processing becomes complicated, and there is a possibility that it does not lead to an improvement in the determination accuracy. For this reason, the number of modes is preferably 6 or less, and more preferably 4 or less.

[0061] In the second embodiment described above, the predetermined time t 1 and the predetermined time t 2 in each of the low kinematic viscosity mode, the medium kinematic viscosity mode, and the high and low kinematic viscosity modes 1 and the second sampling time T 2As (the timing), the value stored in the storage means 34 in advance is used. Thereby, a wide kinematic viscosity range can be covered with a simple information processing process.

[0062] 3. Third Embodiment Finally, the property determination system of the third embodiment will be described. The property determination system of the third embodiment is also for determining the kinematic viscosity of the lubricating oil (liquid to be measured), similar to the property determination systems of the first and second embodiments. In the following, mainly, the parts different from the property determination systems of the first and second embodiments in the property determination system of the third embodiment will be described. For other parts, in the property determination system of the second embodiment, a configuration similar to that of the property determination system of the first or second embodiment can also be adopted.

[0063] In the property determination system of the second embodiment, the information processing unit 30 can switch between a plurality of modes, and for each mode, a conversion formula for property determination and a predetermined time t 1 and the predetermined time t 2 were stored in the storage means 34 in advance. In contrast, in the property determination system of the third embodiment, the information processing unit 30 itself determines the lengths of the predetermined time t 1 and the predetermined time t 2 .

[0064] That is, in the third embodiment, the information processing unit 30 includes sampling timing determination means (not shown) for determining the lengths of the predetermined time t 1 and the predetermined time t 2 (the timing at the first sampling T 1 and the second sampling T 2 ) based on the temperature measurement data acquired by the data acquisition means 32. The sampling timing determination means first obtains the point at which the increase rate of the temperature measurement data becomes equal to or less than a certain value, and determines that point as the second sampling time T 2 . Subsequently, the determined timing of the second sampling T 2 (the predetermined time t 2Based on the length) at the first sampling time T 1 The timing (predetermined time t 1 of the length) is determined. The conversion formula for property determination uses the same one regardless of the predetermined time t 1 and the length of the predetermined time t 2 . This can reduce the effort of preparing multiple conversion formulas for property determination.

Example

[0065] <Experimental Example 1> The kinematic viscosities of the standard liquid JS100 for viscometer calibration and the hydraulic oil VG46 were determined by the same information processing as in the property determination system of the first embodiment. As shown in FIG. 2, for the heating unit 10 and the temperature measuring unit 20, those formed on one sensor chip 40 were adopted. As the heating unit 10, a thin-film heater element was used. As the temperature measuring unit 20, a metal thin film (such as a platinum thin film) was used. The substrate 42 was made of quartz glass. The output of the heating unit was set to about 100 mW to 200 mW. As the information processing unit 30, a computer was used.

[0066] [Reference Measurement] First, a reference measurement for obtaining the conversion formula for property determination was performed using the standard liquid JS100 for viscometer calibration as the reference measurement liquid. FIG. 8 is a graph showing the results of the reference measurement performed in Experimental Example 1. As shown in FIG. 8, for each of the JS100 with the temperature adjusted to about 30 °C, about 50 °C, about 70 °C, or about 90 °C in the reference measurement, the kinematic viscosity [cSt] was measured using a measuring device conforming to JIS K2283, and heating and temperature measurement were performed using the sensor chip 40. At the first sampling time T 1 the value D of the temperature measurement data 1 (output voltage Vf [mV]), and the second sampling time T 2 the value D of the temperature measurement data 2 (output voltage Vf [mV]) and the difference ΔD 12 [mV] were obtained. The kinematic viscosity [cSt] is on the vertical axis, and the difference ΔD 12On a graph with the horizontal axis being [mV], plot the results obtained from a reference measurement liquid at approximately 30°C, approximately 50°C, approximately 70°C, or approximately 90°C, and approximate with a quadratic function to obtain the difference ΔD 12 A conversion formula for property determination for converting to kinematic viscosity was obtained. The time from the start of heating T 0 to the first sampling time T 1 is 3 seconds, and the time from the start of heating T 1 to the second sampling time T 0 is 30 seconds. The time (predetermined time t 2 ) from the start of heating T 2 to the second sampling time T is 30 seconds.

[0067] [Determination of kinematic viscosity] For the viscometer calibration standard liquid JS100 and the hydraulic oil VG46, the same sensor chip 40 used in the reference measurement was used, and the determination for the same year was carried out using the conversion formula for property determination obtained in the reference measurement. For JS100, the determination was carried out with the liquid to be measured adjusted to approximately 20°C, approximately 30°C, approximately 40°C, approximately 50°C, approximately 60°C, approximately 70°C, approximately 80°C, or approximately 90°C respectively. For VG46, the determination was carried out with the liquid to be measured adjusted to approximately 20°C, approximately 25°C, approximately 30°C, approximately 35°C, approximately 40°C, approximately 45°C, approximately 50°C, approximately 60°C, approximately 75°C, or approximately 90°C respectively. At the time of determination, the temperature measured by the temperature measuring unit 20 immediately before starting the heating of the heating unit 10 was recorded and used as the liquid temperature [°C] of the liquid to be measured. To verify the determination accuracy, for the liquid to be measured adjusted to the same temperature as above, the kinematic viscosity [cSt] was actually measured with a measuring device conforming to JIS K2283. In this case, the liquid temperature [°C] of the liquid to be measured was measured using a calibrated thermometer.

[0068] [Results] Figure 9 is a graph showing the determination results of the kinematic viscosity of the liquid to be measured in Experimental Example 1. Fig. 9(a) shows the determination results of the standard liquid JS100 for viscometer calibration, and Fig. 9(b) shows the determination results of the hydraulic oil VG46. The circles in the graphs of Fig. 9(a) and Fig. 9(b) are the kinematic viscosities determined using the sensor chip 40 plotted on the graph. The dashed lines are the results of actually measuring the kinematic viscosities of the respective liquids to be measured with a measuring device conforming to JIS K2283, plotted on the graph and connected with a smooth curve.

[0069] As shown in Figs. 9(a) and 9(b), by using the temperature measurement data after the first sampling time T 1 it was possible to determine the kinematic viscosity of the liquid to be measured with high accuracy. In particular, the determination of the kinematic viscosity of VG46 shown in Fig. 9(b) was able to be performed with high accuracy even though it was performed using the conversion formula for property determination by reference measurement using JS100 (that is, the calibration curve created for different liquid types).

[0070] <Experimental Example 2> The kinematic viscosity of the high kinematic viscosity oil (10W40) was determined in the medium kinematic viscosity mode and the high kinematic viscosity mode, respectively, by the same information processing as the property determination system of the second embodiment. The same sensor chip as in Experimental Example 1 was used. The value D 1 of the temperature measurement data at the first sampling time T 1 and the value D 2 of the temperature measurement data at the second sampling time T 2 and the difference ΔD 12 were substituted into the conversion formula for property determination to determine the kinematic viscosity. The predetermined time t 1 in the medium kinematic viscosity mode was 3 seconds, the predetermined time t 2 was 15 seconds, the predetermined time t 1 in the high kinematic viscosity mode was 5 seconds, and the predetermined time t 2 was 30 seconds. The conversion formulas for property determination in the medium kinematic viscosity mode and the high kinematic viscosity mode were, respectively, with JS100 as the reference measurement liquid, the predetermined time t 1 and the predetermined time t 2Reference measurements were performed using [the relevant method], and the equations obtained by the same procedure as the reference measurements in Experimental Example 1 were used. For the determination of kinematic viscosity, highly viscous oils with their temperatures adjusted to approximately 30°C, approximately 40°C, approximately 50°C, approximately 60°C, approximately 70°C, approximately 80°C, or approximately 90°C were used as the liquids to be measured, and the measurements were carried out 5 times at each temperature. At the time of determination, the temperature measured by the temperature measuring unit 20 immediately before starting the heating of the heating unit 10 was recorded and used as the liquid temperature [°C] of the liquid to be measured. To verify the determination accuracy, for the liquid to be measured adjusted to the same temperature as above, the kinematic viscosity [cSt] was actually measured using a measuring device conforming to JIS K2283. In this case, the liquid temperature [°C] of the liquid to be measured was measured using a calibrated thermometer.

[0071] [Results] Figure 10 is a graph showing the determination results when the kinematic viscosity of a highly viscous oil was determined in the medium kinematic viscosity mode and the high kinematic viscosity mode, respectively, in Experimental Example 2. Figure 10(a) shows the results when determined in the medium kinematic viscosity mode, and Figure 10(b) shows the results when determined in the high kinematic viscosity mode. The circles in the graphs of Figure 10(a) and Figure 10(b) are the results determined using the sensor chip 40 plotted on the graph. Also, the dashed line is the result of actually measuring the kinematic viscosity of the same liquid to be measured using a measuring device conforming to JIS K2283, plotted on the graph and connected with a smooth curve.

[0072] As shown in Figure 10(a), when the kinematic viscosity of a highly viscous oil was determined in the medium kinematic viscosity mode, it was difficult to improve the accuracy in the low-temperature region (high-viscosity region). In contrast, as shown in Figure 10(b), when determined in the high kinematic viscosity mode, high accuracy could be achieved even in the low-temperature region (high-viscosity region).

Explanation of Symbols

[0073] 10 Heating unit 20 Temperature measuring unit 30 Information processing unit 31 Control means 32 Data acquisition means 33 Property determination means 34 Memory means 35 Mode determination means 40 Sensor chip 41 Base part 42 Substrate 43 Insulating film 44 Protective film T 0 At the start of heating T 1 At the first sampling T 2 At the second sampling T E At the end of heating

Claims

1. A property determination system for determining the properties of a liquid to be measured, comprising: a heating unit for locally heating the liquid to be measured; a temperature measurement unit for measuring the temperature of the liquid to be measured in the vicinity of the heating unit; an information processing unit capable of determining the properties of the liquid to be measured based on the temperature measurement data obtained by the temperature measurement unit; and The information processing unit determines the property of the liquid to be measured based on the temperature measurement data after the first sampling time T １ , which is the time point when a predetermined time t １ has elapsed since the heating start time T when the heating unit started heating among the temperature measurement data. ０ from the heating start time T １ when a predetermined time t １ has elapsed, that is, the first sampling time T a property determination system.

2. The property determination system according to Claim 1, wherein the property of the liquid to be measured is the kinematic viscosity, the degree of deterioration, or the degree of impurity contamination of the liquid to be measured.

3. The information processing unit is Temperature measurement data value D at the first sampling time T １ and １ and Start heating time T ０ From, a predetermined time t １ A predetermined time t longer than ２ The second sampling time T when the time has elapsed ２ The value D of the temperature measurement data at ２ And Difference ΔD １２ Based on this, determine the properties of the liquid to be measured the property determination system according to Claim 1.

4. The information processing unit can switch between a plurality of modes with different timings at the first sampling time T １ The property determination system according to claim 1, which can switch between a plurality of modes with different timings at the first sampling time T

5. The information processing unit, among the temperature measurement data, at the mode determination first sampling time T ０ after a predetermined time t Ｐ has elapsed, based on the temperature measurement data after that, determines which one of the plurality of modes to use. The property determination system according to claim 4 Ｐ ​

6. The property determination system according to Claim 1, wherein the heating unit and the temperature measurement unit are provided in a storage tank for the liquid to be measured or in a flow path for the liquid to be measured.

7. A method for determining the properties of a liquid to be measured, which uses the property determination system according to any one of Claims 1 to 6 to determine the properties of the liquid to be measured.

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