Level meter

Abstract

The invention provides a level meter. The level meter can accurately measure the horizontal height of an object stored in a container. The level meter includes a distribution determination unit, an extraction unit, a candidate determination unit, and a display section. The distribution determination unit determines a reception intensity distribution of a reflected signal with respect to a distance from the level meter based on a reception intensity of the reflected signal generated by reflection of the measurement signal. A candidate determination unit extracts a plurality of combinations of peak positions and peak intensities from the reception intensity distribution by an extraction unit, and determines these combinations as a plurality of peak candidates. The display section displays a candidate confirmation screen including a measurement value corresponding to each of the plurality of peak candidates and a reception intensity scale related to the reception intensity.

Description

Technical Field

[0001] The present invention relates to a level meter for measuring the horizontal height of an object. Background Art

[0002] In containers storing flowable materials such as liquids, powders, and granules, a level meter can be used to measure the height of the material interface, that is, the horizontal height (liquid level, powder upper surface height, etc.).

[0003] The level meter described in JP 2014-002091A includes a probe to which a pulse signal is input, and measures a level based on the pulse input to the probe and the pulse reflected by a measurement target.

[0004] Depending on the type of the level meter, a signal such as a radio wave may be transmitted from the level meter toward the object without using a probe to measure the level of the object stored in the container. The level meter may measure the level based on the transmitted signal and the signal reflected at the interface of the object.

[0005] However, there may be elements in the container that reflect the signal in addition to the interface of the object. For example, in the case where a stirrer for stirring the object is provided in the container, the stirrer may reflect the signal. In the case where the container is, for example, a large tank, a ladder may be provided for an operator to perform work in the tank. The ladder in the tank may also reflect the signal. In addition, in the case where the object is a substance that easily transmits signals (oil, etc.), the signal may pass through the object, and the signal may be reflected at the bottom of the container.

[0006] When there are elements of reflected signals other than the interface of the object, the level meter cannot correctly measure the level of the object unless the signal reflected at the interface of the object is distinguished from the other signals. Summary of the invention

[0007] In view of the above problems, an object of the present invention is to provide a level meter capable of correctly measuring the level of objects stored in a container.

[0008] In order to solve the above-mentioned problem, a level meter as an example of an embodiment of the present invention is a level meter for measuring the horizontal height of an object stored in a container, and the level meter includes: a sending / receiving unit, the sending / receiving unit including a sending circuit for sending a measurement signal for measuring the horizontal height and a receiving circuit for receiving a reflection signal generated due to reflection of the measurement signal; a distribution determining unit, the distribution determining unit determining the receiving intensity distribution of the reflection signal relative to the distance from the level meter based on the receiving intensity of the reflection signal received by the receiving circuit; and an extracting unit, the extracting unit extracting the receiving intensity distribution of the reflection signal from the receiving intensity determined by the distribution determining unit. A receiving intensity distribution is used to extract a peak position and a peak intensity; a measurement value determination unit, which determines a measurement value related to the distance to the object or the horizontal height based on the peak position extracted by the extraction unit; a candidate determination unit, which extracts a plurality of combinations of the peak position and the peak intensity from the receiving intensity distribution determined by the distribution determination unit through the extraction unit, and determines the plurality of combinations as a plurality of peak candidates; and a display unit, which displays information related to the measurement value and the receiving intensity corresponding to each peak candidate among the plurality of peak candidates determined by the candidate determination unit.

[0009] According to the present invention, a plurality of peak candidates extracted from the receiving intensity distribution of the reflected signal are displayed on the display section. These peak candidates include a peak corresponding to the horizontal height of the object and a peak corresponding to an element other than the object. By selecting a peak corresponding to the horizontal height of the object from the peak candidates, the level meter can correctly measure the horizontal height by distinguishing the signal reflected at the interface of the object from other signals. The level meter can optimally set the setting of the measurement conditions required for determining the measurement value related to the horizontal height of the object based on the receiving intensity distribution and the peak corresponding to the horizontal height of the object. By optimally setting the measurement conditions, the level meter can maintain a state in which the horizontal height is correctly measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a perspective view showing a level meter;

[0011] Figure 2 is a cross-sectional view showing a level meter;

[0012] Figure 3 is a diagram showing a state in which the level meter is attached to a container accommodating an object;

[0013] Figure 4 is a block diagram schematically showing an example of the relationship between components of a level meter;

[0014] Figure 5is a diagram showing an example of the configuration of a radar control unit and a transmission / reception unit;

[0015] Figure 6 is a diagram showing the relationship between a measurement signal and a reflection signal;

[0016] Figure 7 is a graph showing a received intensity distribution in a case where a plurality of peaks appear;

[0017] Figure 8 is a diagram showing state transitions of the level meter;

[0018] Fig. 9 is a diagram showing a menu screen;

[0019] Fig.10 is a diagram showing the state transition of the level meter in the adjustment function;

[0020] Fig.11 is a flowchart showing the processing flow in the optimization mode;

[0021] Fig.12 is a diagram showing the contents to be set according to the diagnosis result;

[0022] Fig.13 is a flowchart showing the processing flow in restricted mode;

[0023] Fig.14 is a diagram showing an adjustment mode selection screen;

[0024] Fig.15 is a diagram showing a waiting screen;

[0025] Fig.16 is a diagram illustrating a candidate selection message;

[0026] Fig.17 is a diagram showing a candidate confirmation screen;

[0027] Fig.18 is a diagram showing an advisory message in a case where the influence of an environmental signal is large;

[0028] Fig.19 2 is a diagram showing a calculation result confirmation screen of the close-range measurement limitation;

[0029] Fig. 20 is a diagram showing an advisory message in a case where the calculation result of the close distance measurement limit is not optimal;

[0030] Fig.21 is a diagram showing a start confirmation screen for optimization processing;

[0031] Fig. 22 is a diagram showing an optimization completion screen;

[0032] Fig.23 is a diagram of a display screen showing the presence or absence of a learning execution result;

[0033] Fig.24 is a diagram showing a screen for confirming the necessity of erasing the learning execution result;

[0034] Fig.25 is a diagram showing a learning execution confirmation screen;

[0035] Fig.26 is a diagram showing a numerical value input screen related to distance;

[0036] Fig. 27 is a diagram showing a learning completion screen;

[0037] Fig.28 is a perspective view showing another example of a level meter;

[0038] Fig.29 is a diagram showing another example of a current value display screen;

[0039] Fig.30 is a diagram showing another example of a candidate confirmation screen;

[0040] Fig.31 is a diagram showing another example of the optimization completion screen;

[0041] Fig.32 is a perspective view showing still another example of a level meter;

[0042] Fig.33 is a view showing screen transition of a display section of a remote controller in an adjustment function; and

[0043] Fig.34 : is a view showing screen transition of the display section of the remote controller in the limited mode. DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that in the accompanying drawings, the same or corresponding parts are represented by the same reference numerals, and their description will not be repeated basically. In addition, in the following description, terms indicating positions or directions such as front, back, left, right, top, and bottom may be used, but these terms are used to facilitate understanding of the embodiments. Unless otherwise explicitly stated, these terms are not limited to front, back, left, right, top, bottom, etc. in a geometrically strict sense.

[0045] Next, a level meter 10 as an example of an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 , Figure 2 and Figure 3An example of the structure and use of the level meter 10 is described below. Figure 1 , a perspective view of the level meter 10 according to the present embodiment is shown. Figure 2 Shows Figure 1 sectional view of a level meter 10. Figure 3 A state in which the level meter 10 is attached to a container 70 (eg, a tank) storing an object 72 is shown.

[0046] The level meter 10 is a device that measures a level Y of an object 72 to be measured (e.g., liquid, powder, granular material, etc.). The measured level Y is the height of an interface 74 of the object 72 in the container 70. Specific examples of the level Y include a distance from the bottom of the container 70 to the liquid level of the liquid contained in the container 70. A measurement axis is set in the level meter 10, and the level meter 10 measures the level Y along the measurement axis.

[0047] As an example of the usage state of the level meter 10, Figure 3 The container 70 stores, for example, liquid (water, oil, chemical solution, etc.) as an object 72 in the liquid processing facility. For example, when the object 72 in the container 70 is supplied to the liquid processing process, etc., the level Y of the object 72 in the container 70 decreases. In addition, when the container 70 is replenished with the object 72, the level Y of the object 72 in the container 70 increases. For example, the water injection port 75 is provided on the outer wall ( Figure 3 The water injection pipe 76 is fluidically connected to the container 70 via the water injection port 75. Then, the water injection pipe 76 is connected to a water injection device 78 (including devices such as pumps, valves, etc.) provided outside the container 70. The water injection device 78 is a device for supplying (injecting) the object 72 from the outside of the container 70 into the container 70. The water injection device 78 adjusts the amount of water injected into the container 70 according to the level Y of the object 72 in the container 70. In addition, the water injection device 78 stops injecting water according to the level Y of the object 72 in the container 70. The water injection device 78 controls the replenishment of the object 72 to the container 70 according to the level Y of the object 72 in the container 70, so that the level Y of the object 72 in the container 70, which is reduced as the object 72 is consumed, for example, through a liquid processing process, falls within a predetermined range.

[0048] Figure 1 The level meter 10 has a generally cylindrical shape extending in the longitudinal direction A (the direction of the measuring axis). The level meter 10 includes a housing 15 and a sensor unit 16, and the housing 15 and the sensor unit 16 are arranged along the longitudinal direction A. The sensor unit 16 is disposed at one end side ( Figure 1 The housing 15 is disposed on the other end side ( Figure 1Hereinafter, one end (lower end) of the sensor unit 16 in the longitudinal direction A is referred to as the measuring end 40. Figure 2 As shown, a dielectric lens 48 is provided at the measuring end 40. Hereinafter, one end side of the level meter 10 in the longitudinal direction A may be referred to as a lower side, and the other end side in the longitudinal direction A may be referred to as an upper side.

[0049] like Figure 3 As shown, Figure 1 The level meter 10 in the embodiment measures the horizontal height Y of the object 72, wherein the measuring end 40 points to the object 72. For example, in the case where the level meter 10 measures the height of the liquid (interface 74), the longitudinal direction A of the level meter 10 faces the same direction as the direction of change of the liquid level height of the liquid, that is, the vertical direction (height direction, gravity direction).

[0050] Figure 3 The level meter 10 in the embodiment transmits a radio wave as a measurement signal Tx from the measuring end 40 to the object 72. Then, the reflected signal Rx obtained by reflecting the measurement signal Tx at the interface 74 of the object 72 is received by the measuring end 40. The level meter 10 calculates the horizontal height Y of the object 72 based on the measurement signal Tx and the reflected signal Rx. For example, in the case of measuring using the time of flight (ToF) method, the level meter 10 calculates the distance YA from the measuring end 40 to the interface 74 based on the difference between the measurement signal Tx and the reflected signal Rx, and calculates the horizontal height Y based on the distance YA. In addition, for example, in the case of measuring by a radar method using a frequency modulated continuous wave (FMCW), the level meter 10 calculates the distance YA from the measuring end 40 to the interface 74 based on the frequency of the waveform obtained by mixing the transmission signal Tx and the reflected signal Rx, and calculates the horizontal height Y based on the distance YA.

[0051] like Figure 1 As shown, an attachment screw 18 in which threads are engraved on the surface of a cylinder is provided above the measuring end 40 in the sensor unit 16. An attachment portion 17 having a larger diameter than the attachment screw 18 is provided above the attachment screw 18. Figure 1The attachment portion 17 in the embodiment has a nut shape. It should be noted that the attachment portion 17 is not limited to a nut shape as long as it is a structure capable of attaching the level meter 10 to an attachment target (e.g., a container 70 for storing liquid). For example, the attachment portion 17 may have a cylindrical shape in which an anti-skid protrusion is formed. When the level meter 10 is attached or detached (rotationally attached or detached) while rotating around the longitudinal direction A relative to the attachment target, the anti-skid protrusion of the attachment portion 17 serves as an anti-skid portion. In addition, an attachment flange for attaching the level meter 10 to the attachment target may be formed instead of the attachment portion 17 and the attachment screw 18. In addition, even in the case where the attachment flange is formed, the attachment portion 17 and the attachment screw 18 may be provided in addition to the attachment flange.

[0052] Figure 3 The level meter 10 in the container 70 is attached to the upper side of the container 70. An attachment hole 71 is provided above the container 70. The attachment hole 71 is a screw hole, and the attachment screw 18 of the level meter 10 is screwed into the attachment hole 71, whereby the level meter 10 is attached to the container 70. For example, the user of the level meter 10 can screw the attachment screw 18 into the attachment hole 71 by rotating the nut-shaped attachment portion 17 while the front end of the attachment screw 18 is aligned with the attachment hole 71. Note that the structure for attaching the level meter 10 to the container 70 is not limited thereto. For example, it is also possible that no thread is provided on the attachment hole 71, and a nut is additionally screwed into the attachment screw 18 exposed inside the container 70, so that the level meter 10 can be attached to the container 70. In addition, the level meter 10 can be attached to a mounting bracket provided above the tank 70 by using a nut and an attachment screw 18 while the upper surface of the container 70 is open. In addition, the method of attaching the level meter 10 to the container 70 is not limited to the threaded connection using the attachment screws 18, and threads may not be formed on the outer peripheral surface of the sensor unit 16. For example, a flange may be provided on one or both of the level meter 10 and the container 70, and the level meter 10 may be attached to the container 70 by bolting the flange to the level meter 10 or the container 70.

[0053] The housing 15 disposed above the sensor unit 16 is provided with a display section 20. The display section 20 is provided on the outer peripheral surface of the housing 15 extending along the longitudinal direction A. The display section 20 preferably includes an active matrix type display device (active matrix display) capable of displaying various types of information. For example, the display section 20 includes a liquid crystal display (LCD). In particular, the display section 20 preferably includes an LCD capable of color display (display with multiple colors).

[0054] The display unit 20 may be a two-line reflective color liquid crystal display that performs power transmission and reception and data communication through two power lines. The two-line display performs data communication by changing the magnitude of the current transmitted via the power line. For example, the consumption current of the power line varies within the range of 4 to 20 mA. The content of the data to be transmitted and received is represented by the magnitude of the consumption current. In addition, the reflective display allows the user to visually recognize the display content through the external light reflected on its surface. Although the two-line display can use small power consumption, the two-line reflective color liquid crystal display can perform various displays with small power consumption.

[0055] The display section 20 displays the level Y of the object 72 measured by the sensor unit 16. Figure 1 and Figure 3 In the embodiment, a bar display 22 whose length is extended and contracted according to the value of the horizontal height Y is displayed on the display section 20. In addition, the display section 20 also displays a color scale 24 (an example of a ruler) color-coded with a plurality of colors. The length direction of the color scale 24 is arranged along the extension / contraction direction of the bar display 22. The color scale 24 includes a plurality of ( Figure 1 The color scale 24 has three (three) partitions. The partitions of the color scale 24 correspond to a plurality of level ranges set relative to the level Y of the object 72, and the level ranges are defined by a plurality of level setting values ​​(eg, thresholds) set relative to the level Y.

[0056] The display section 20 displays the relative position of the horizontal height Y with respect to the container 70 storing the object 72 and the bar display 22. Specifically, in the container icon 25 imitating the container 70, the bar display 22 stretches and contracts in length according to the value of the horizontal height Y of the object 72. The length of the bar display 22 relative to the size of the container icon 25 corresponds to the relative position of the horizontal height Y of the object 72 with respect to the entire container 70.

[0057] Then, a bar arrow 22a is displayed at the front end (upper end) in the extension / contraction direction of the bar display 22. The bar arrow 22a indicates a position in the color scale 24 corresponding to the length of the bar display 22. The color scale 24 indicates to which level range the measured level Y belongs among a plurality of level ranges defined by the level setting value.

[0058] The color scale 24 includes a plurality of partitions. The plurality of partitions of the color scale 24 are divided into a plurality of horizontal ranges. Then, in the display section 20, the plurality of partitions of the color scale 24 are arranged along the rising / falling direction of the horizontal height Y. The container icon 25 and the bar display 22 are displayed next to the color scale 24 (displayed side by side with the color scale 24). Since the color scale 24 is displayed side by side with the container icon 25 and the bar display 22 in the display section 20, the relative position of the horizontal setting value relative to the container 70 is displayed together with the bar display 22.

[0059] In addition, the display unit 20 also displays an auxiliary display unit 26 indicating information in addition to the bar display 22 and the color scale 24. Figure 1 In the example, the numerical value (mm, millimeter) of the measured horizontal height Y is displayed on the auxiliary display unit 26.

[0060] In addition, the display section 20 also displays an output state display section 27. The output state display section 27 displays the state of the signal line, and the output of the signal line changes according to the relationship between the measured level Y and the level setting value. For example, when a signal is sent from a specific signal line when the level Y exceeds the threshold value determined as the level setting value, a number corresponding to the signal line is displayed in the output state display section 27. For example, Figure 1 , the bar arrow 22a indicates the uppermost division among the three divisions of the color scale 24. Such a state of the display section 20 indicates that two threshold values ​​are set as level setting values, and the measured level Y exceeds both of the two threshold values.

[0061] Then, when the signal line is ready to output a signal when the measured level Y exceeds the threshold, Figure 1 The two signal lines corresponding to the two thresholds in the state output signals. Figure 1 In order to indicate that signals are output from two signal lines, numbers (here, "1" and "2") corresponding to the two signal lines of the output signal are displayed on the output state display portion 27.

[0062] In addition, the operation unit 30 is also provided in the same surface as the outer surface of the housing 15 on which the display section 20 is provided. Figure 1 The operation unit 30 is provided adjacent to the display section 20 and includes a menu key 32 and a direction key 33 arranged along the longitudinal direction A. Furthermore, the direction key 33 includes an up key 36 and a down key 35 arranged along the longitudinal direction A.

[0063] The connection portion 12 is provided on the upper side of the housing 15 . Figure 1 The connection part 12 in the embodiment has a cylindrical shape extending in the longitudinal direction A. The outer peripheral surface of the cylindrical connection part 12 is a connection screw part 14 with threads cut thereon. Figure 2As shown, the connection portion 12 includes an external input terminal 12C and an external output terminal 12D. The external input terminal 12C is a terminal for inputting a signal or power or both from the outside to the level meter 10. The external output terminal 12D is a terminal for outputting a signal from the level meter 10 to the outside. Each of the external input terminal 12C and the external output terminal 12D may include a plurality of signal lines or a plurality of terminals. For example, a signal may be output to the outside from different signal lines or different output terminals according to the level range to which the measured level Y belongs.

[0064] Figure 3 The connection cable 92 shown is connected to the connection part 12. The connection cable 92 connects the management device 90 (e.g., a programmable controller) provided outside the container 70 to the level meter 10. A signal indicating the level Y of the object 72 measured by the level meter 10 is transmitted (output) to the management device 90 through the external output terminal 12D (a part of the output part 66 described later) of the connection part 12 and the connection cable 92. The management device 90 manages the operation of the entire facility including the container 70 based on the signal received from the level meter 10.

[0065] In addition, the status light 52 is provided between the connection part 12 and the display part 20 so as to surround the lower side (root) of the connection part 12. The luminous state of the status light 52 changes according to the measured horizontal height Y of the object. The user can roughly understand the state of the object by visually observing the luminous state of the status light 52. The status light 52 can emit light of various luminous colors (e.g., green, yellow, red, etc.). The status light 52 preferably emits light in a luminous color corresponding to the horizontal height range to which the horizontal height Y measured by the level meter 10 belongs. For example, the status light 52 can emit light of the same color as the color of the partition indicated by the bar arrow 22a in the color mark 24, and the color mark 24 is color-coded by a plurality of colors for each partition.

[0066] like Figure 2 As shown in the cross-sectional view of FIG. 1 , a sensor IC 41 (IC: Integrated Circuit) and a sensor board 42 supporting the sensor IC 41 are provided inside the sensor unit 16. The sensor IC 41 performs transmission and reception of radio waves and signal processing for measuring the horizontal height Y of the object 72. The signal processed by the sensor IC 41 is transmitted to the display panel 60 provided in the end portion 21.

[0067] As the sensor IC 41, for example, an MMIC (Monolithic Microwave Integrated Circuit) is used. An MMIC is an IC in which a plurality of semiconductor components that perform transmission of radio waves, reception of radio waves, signal processing based on transmitted and received radio waves, and the like are integrated into a single semiconductor device (one chip). Figure 2 In the sensor IC 41, the antenna is integrated with the MMIC using the antenna in package (AiP) technology or the antenna on package (AoP) technology. Figure 2 In the embodiment of the present invention, the sensor IC 41 is an antenna integrated package (antenna on package) in which a transmission circuit 43T for transmitting radio waves and a reception circuit 43R for receiving radio waves are integrated in a single semiconductor device. Since an antenna-integrated MMIC is used as the sensor IC 41, the volume occupied by the configuration for transmitting and receiving radio waves is reduced, and the overall size of the level meter 10 becomes compact. Note that the sensor IC 41 is not limited to a single antenna-integrated MMIC, and may include a plurality of ICs. The sensor IC 41 may include, for example, an MMIC and a microcomputer. Then, the antenna-integrated MMIC may include a radio wave transmitting antenna, a radio wave receiving antenna, and a circuit for performing radio wave transmission / reception control, and the microcomputer may include a circuit for performing signal processing or arithmetic processing based on a received signal received from the antenna-integrated MMIC.

[0068] The sensor IC 41 is mounted on the lower surface of the sensor board 42. The sensor board 42 is an electronic circuit board in which various electronic circuit elements are arranged on a board made of an insulator such as glass or resin. Figure 2 In the embodiment, the sensor plate 42 is arranged in a direction orthogonal to the longitudinal direction A ( Figure 2 in the horizontal direction).

[0069] The measuring end 40 is located below the sensor plate 42 . Figure 2 The measuring end 40 includes a waveguide 45, a horn antenna 46, and a dielectric lens 48 as an internal structure. In the case where the sensor IC 41 is an antenna-integrated MMIC, a radio wave serving as a measurement signal Tx is transmitted from a transmission circuit 43T of the sensor IC 41. The measurement signal Tx transmitted from the sensor IC 41 is guided toward the object 72 through the waveguide 45, the horn antenna 46, and the dielectric lens 48 in sequence. In addition, a reflection signal Rx reflected by the object 72 and incident on the measuring end 40 is guided toward the receiving circuit 43R of the sensor IC 41 through the dielectric lens 48, the horn antenna 46, and the waveguide 45 in sequence.

[0070] The waveguide 45, the horn antenna 46, and the dielectric lens 48 arranged inside the sensor unit 16 guide the traveling direction of the radio wave in the longitudinal direction A, and therefore they exhibit strong directivity with respect to the radio wave by combining as a whole. Therefore, even if the length direction dimension (the length along the longitudinal direction A) is small, the sensor unit 16 can properly guide the measurement signal Tx and the reflection signal Rx. In addition, by properly guiding the measurement signal Tx and the reflection signal Rx, even if the position of the transmission circuit 43T and the position of the receiving circuit 43R are different in the sensor IC 41, the transmission of the measurement signal Tx and the reception of the reflection signal Rx can be performed by the common measurement end 40. Therefore, by using the waveguide 45, the horn antenna 46, and the dielectric lens 48, the designer of the level meter 10 can reduce the length direction dimension of the level meter 10 including the sensor unit 16, and can make the level meter 10 compact as a whole.

[0071] On the other hand, in the housing 15 , the rotating mechanism 19 is provided on the upper side of the sensor plate 42 . Figure 2 The rotating mechanism 19 in the embodiment is provided at the lower end of the housing 15 (one end in the longitudinal direction A), that is, between the housing 15 and the sensor unit 16. The rotating mechanism 19 can make the housing 15 relatively rotate with respect to the sensor unit 16. The rotating mechanism 19 is arranged so that the axis of rotation is parallel to the longitudinal direction A. Since the rotating mechanism 19 is provided, the user can turn the display part 20 to a direction that is easy to see by rotating the housing 15. In particular, when the level meter 10 is attached to a container 70 (such as a tank) including an object 72 by the attachment screws 18, the user can guide the display part 20 in a direction in which the user can easily see the display part 20 without moving the entire level meter 10.

[0072] In the housing 15, a display panel 60 is provided above the rotating mechanism 19. The display panel 60 is an electronic circuit board in which various electronic circuit elements are arranged on a board made of an insulator such as glass or resin. A signal processing circuit for controlling the display section 20 is mounted on the display panel 60. The display panel 60 receives a signal from the sensor IC 41 and converts the level Y of the object 72 measured by the sensor unit 16 into a signal for displaying the level on the display section 20. Figure 2 The display panel 60 is provided on the back side of the display unit 20 ( Figure 2 15).

[0073] Figure 2The display unit 20 in the embodiment includes a display device 28 and a transparent display window 29. The display device 28 is, for example, an LCD, in particular, an LCD capable of color display. The display window 29 is, for example, a plate made of an optically transparent material such as glass, acrylic, polyarylate, or polycarbonate, and optically transmits the display content of the display device 28 to the outside of the housing 15.

[0074] The status light 52 provided between the display portion 20 and the connection portion 12 includes a plurality of status LEDs 50 (light emitting diodes (LEDs)) and a transmission window 53. The plurality of status LEDs 50 are provided above the display panel 60 and the display portion 20. The light emission state of the status LEDs 50 changes according to the horizontal height of the object measured by the sensor unit 16. In addition, a transmission window 53 including a light-diffusing member (such as a light-diffusing film) is provided above the status LEDs 50. The light emitted from the status LEDs 50 is guided to the outside of the housing 15 through the transmission window 53. Therefore, as the light emission state of the status LEDs 50 changes according to the horizontal height Y of the object, the light emission state of the status light 52 also changes. In addition, since the transmission window 53 includes a light-diffusing member, the light emitted from the status LEDs 50 is uniformly diffused in all directions around the connection portion 12.

[0075] The light emitting state of the status LED 50 changes according to the horizontal height Y of the object 72 measured by the sensor unit 16. The light emitted from the status LED 50 is guided to the outside of the housing 15 through the transmission window 53. Therefore, as the light emitting state of the status LED 50 changes according to the horizontal height Y of the object 72, the light emitting state of the status lamp 52 also changes. In addition, since the transmission window 53 includes a member that diffuses light, the light emitted from the status LED 50 is diffused in a direction intersecting the longitudinal direction A. Therefore, the user can easily visually grasp the light emitting state of the status lamp 52 from a long distance.

[0076] The status LED 50 may emit a single color light (e.g., red, yellow, green, etc.) or may emit light by switching a plurality of colors (e.g., red, yellow, green, etc.). When the status LED 50 emits light by switching a plurality of colors, a plurality of light emitting elements emitting light of different colors may be included in one LED, or a combination of a plurality of LEDs emitting light of different colors may be arranged as the status LED 50. Then, the status LED 50 may emit light by mixing a plurality of colors. In addition, when the status LED 50 emits light by switching a plurality of colors, the status LED 50 may emit light of a color corresponding to the color of a subarea of ​​the color scale 24, the subarea of ​​the color scale 24 corresponding to the level range to which the measured level Y belongs.

[0077] Next, we will refer to Figure 4 The relationship between the components of the level meter 10 is described. Figure 4 1 is a block diagram schematically showing an example of the relationship between the components of the level meter 10. Figure 4 As shown, the sensor IC 41 of the sensor unit 16 includes a transmitting / receiving unit 43, a radar control unit 44, and a processing unit 62. The transmitting / receiving unit 43 includes a transmitting circuit 43T for transmitting a measurement signal Tx and a receiving circuit 43R for receiving a reflection signal Rx. The sensor IC 41 may include a plurality of ICs. For example, the sensor IC 41 may include an antenna integrated MMIC and a microcomputer.

[0078] The radar control unit 44 includes a transmission control unit 80 that determines the waveform of the measurement signal Tx, a radar transmission / reception circuit 81 that performs mutual conversion between a digital signal and a radio wave, and a signal processing unit 89 that performs signal processing based on the measurement signal Tx and the reflection signal Rx. In addition, in the case where the sensor IC 41 includes an antenna-integrated MMIC and a microcomputer, the antenna-integrated MMIC may include a part of the radar control unit 44 (the transmission control unit 80 and the radar transmission / reception circuit 81) other than the signal processing unit 89 and the transmission / reception unit 43, and the microcomputer may include the signal processing unit 89 and the processing unit 62.

[0079] The processing unit 62 includes a storage unit 63, a calculation unit 64, a distribution determination unit 911, an extraction unit 912, and a candidate determination unit 913. The storage unit 63 stores various setting values ​​(data) related to the operation of the level meter 10. The calculation unit 64 performs various calculations related to the operation of the level meter 10 based on the setting values ​​stored in the storage unit 63, the signal processing results of the signal processing unit 89, and the like. The storage unit 63 includes storage devices such as a random access memory (RAM) and a read-only memory (ROM). The calculation unit 64 includes a processor such as a central processing unit (CPU). It should be noted that the storage unit 63 and the calculation unit 64 can be arranged on the display panel 60 of the housing 15. Alternatively, the storage unit 63 and the calculation unit 64 can be separately arranged in the sensor unit 16 and the housing 15, respectively, and the stored data and the responsible arithmetic processing can be shared by the sensor unit 16 and the housing 15. In addition, as Figure 4 As shown, the calculation unit 64, the radar transmission / reception circuit 81 of the radar control unit 44, and the signal processing unit 89 together function as a measurement value determination unit 88. The measurement value determination unit 88 performs a process of determining a measurement value related to the distance of the object 72 from the level meter 10 or the horizontal height Y of the object 72 based on the reflection signal Rx received by the receiving circuit 43R and the container information related to the container 70 (for example, the height of the container 70).

[0080] The distribution determination unit 911 determines the reception intensity distribution of the reflection signal Rx with respect to the distance from the level meter 10 based on the reception intensity of the reflection signal Rx received by the receiving circuit 43R. The extraction unit 912 extracts the peak position and the peak intensity from the reception intensity distribution determined by the distribution determination unit 911. The candidate determination unit 913 causes the extraction unit 912 to extract a plurality of combinations of the peak position and the peak intensity from the reception intensity distribution determined by the distribution determination unit 911, and determines the combinations as a plurality of peak candidates.

[0081] On the other hand, the display panel 60 of the housing 15 includes a setting unit 61, an input unit 65, and an output unit 66. The setting unit 61 performs a process of sequentially setting container information related to the container 70 and a plurality of level setting values ​​related to the level Y. The input unit 65 is an interface circuit that inputs an input provided from the outside of the level meter 10 as a signal to the level meter 10. The input provided from the outside of the level meter 10 is, for example, an operation of the operation unit 30 by a user, a control signal provided from an external device (such as a management device 90) via the external input terminal 12C, and the like. The input unit 65 causes the storage unit 63 to store, for example, flag information showing that the operation unit 30 has been operated, and data such as a setting value provided via the external input terminal 12C.

[0082] The output unit 66 is an interface circuit that outputs the signal generated inside the level meter 10 to the outside. The output unit 66 changes, for example, the display content of the display unit 20, the lighting state of the status lamp 52, etc. according to the calculation result (such as the value of the horizontal height Y) of the calculation unit 64. In addition, the output unit 66 sends the calculation result of the calculation unit 64 to an external device via the external output terminal 12D.

[0083] Will refer to Figure 5 and Figure 6 The measurement of the level Y by the level meter 10 is described in detail. Figure 5 4 is a diagram showing a configuration example of the radar transmission / reception circuit 81 and the transmission / reception unit 43 included in the sensor IC 41 . Figure 6 is a diagram showing the relationship between the measurement signal Tx and the reflection signal Rx.

[0084] like Figure 5 As shown, the radar transmit / receive circuit 81 includes a ramp generator 82 , a power amplifier 83 , a low noise amplifier 84 , a mixer 85 , a low pass filter 86 and an analog-to-digital converter 87 .

[0085] The level meter 10 of the present embodiment measures the horizontal height Y by a radar method using FMCW. The ramp wave generator 82 is connected to the transmission control unit 80. When receiving data indicating the waveform of the measurement signal Tx determined by the transmission control unit 80, the ramp wave generator 82 generates a signal having the waveform according to the data. Here, as the waveform of the measurement signal Tx, a waveform with increasing and decreasing repetition frequency is used.

[0086] Figure 6 is a graph showing the variation of the frequency of the measurement signal Tx (and the reflected signal Rx) with respect to time. Figure 6 In the embodiment, the frequency of the measurement signal Tx increases linearly over time from a minimum value (Min) and returns to the minimum value again when reaching a maximum value (Max). In this way, the frequency of the measurement signal Tx increases and decreases repeatedly. Note that the frequency increase / decrease mode is not limited to this, and it is sufficient that the measurement value determination unit 88 can calculate the horizontal height Y based on the comparison between the measurement signal Tx and the reflection signal Rx. For example, a mode that linearly decreases from a maximum value over time and returns to a maximum value again when reaching a minimum value can be used. In addition, a mode that repeats linear increase / decrease between a maximum value and a minimum value can be used. The measurement signal Tx used in this embodiment is a radio wave in the 60GHz frequency band, and the minimum value of the frequency is, for example, 58GHz, and the maximum value is, for example, 69GHz. The frequency band to be used is not limited to this, and, for example, a frequency of 77GHz to 81GHz can be used.

[0087] Depend on Figure 5 The signal generated by the ramp wave generator 82 in the transmission circuit 43T is amplified by the power amplifier 83 and sent to the transmission circuit 43T. The transmission circuit 43T generates a radio wave having a waveform corresponding to the reception signal, and transmits the radio wave as the measurement signal Tx to the object 72. The measurement signal Tx is reflected by the interface 74 of the object 72 to become a reflection signal Rx, and is received by the reception circuit 43R as a reception signal. The reflection signal Rx is a wave having a phase shifted from the phase of the measurement signal Tx.

[0088] like Figure 6 As shown by the dotted line in FIG. 1 , the reflected signal Rx is a wave offset from the measured signal Tx by a time difference Δt. The time difference Δt is the distance YA ( Figure 3 Since the reflected signal Rx reciprocates between the measuring end 40 and the object 72, there exists a relationship of Δt=2×YA / c, where c is the speed of light.

[0089] Next, a frequency difference ΔF corresponding to the magnitude of the time difference Δt is generated between the measurement signal Tx and the reflection signal Rx. According to the waveform of the measurement signal Tx, there is a certain relationship between the frequency difference ΔF and the time difference Δt. The waveform of the measurement signal Tx is a waveform in which the frequency changes linearly over time. That is, according to the frequency change per unit time in the waveform of the measurement signal Tx, there is a certain relationship between the frequency difference ΔF and the time difference Δt. For example, the frequency of the measurement signal Tx increases linearly from the minimum value (Min) over time and reaches the maximum value (Max). In this case, the relationship between the frequency difference ΔF and the time difference Δt is uniquely determined by the difference between the maximum and minimum values ​​of the frequency of the measurement signal Tx as the bandwidth of the frequency modulation, and the relationship of the frequency changes over time. Therefore, the level meter 10 can calculate the time difference Δt based on the frequency difference ΔF as the difference between the measurement signal Tx and the reflection signal Rx. Then, the level meter 10 can calculate (Δt×c / 2). In addition, the level meter 10 is able to calculate the value of the horizontal height Y according to the distance YA. Specifically, the difference between the height of the container 70 (the distance from the bottom of the container 70 to the upper surface of the inside of the container 70) and the distance YA is the value of the horizontal height Y. Therefore, the measurement value determination unit 88 can determine the horizontal height Y of the object 72 based on the reflection signal Rx received by the receiving circuit 43R and the container information on the container 70 (such as the height of the container 70). The container information about the container 70, such as the height of the container 70, the bottom distance Y0 from the level meter 10 to the bottom of the container 70, and the upper surface distance Y1 from the level meter 10 to the upper surface of the inside of the container 70 ( Figure 3 The distance from the level meter 10 is precisely the distance from the measurement reference surface XS (a plane where the value of the distance is regarded as 0) used as the measurement reference in the level meter 10. The position of the measurement reference surface XS is determined in advance before using the level meter 10 (for example, when designing the level meter 10). For example, the position of attaching the level meter 10 to the container 70 ( Figure 3 The position of the outer upper surface of the container 70 in the level meter 10 is determined as the measurement reference surface XS. In terms of the position in the level meter 10, the lower surface of the attachment portion 17 (the upper end of the attachment screw 18) is the measurement reference surface XS. In addition, since there is a certain relationship between the frequency difference ΔF and the time difference Δt according to the waveform of the measurement signal Tx, the corresponding relationship between the frequency difference ΔF and the distance YA can be obtained in advance. The corresponding relationship between the frequency difference ΔF and the distance YA can be stored in the storage unit 63 in advance.

[0090] like Figure 5As shown, a reception signal corresponding to the reflection signal Rx received by the reception circuit 43R is input to the mixer 85 via the low noise amplifier 84. A signal corresponding to the waveform of the measurement signal Tx output from the ramp generator 82 is also input to the mixer 85, and the mixer 85 generates a mixed signal Mx obtained by mixing the waveforms of the measurement signal Tx and the reflection signal Rx. Specifically, the mixer 85 included in the radar transmission / reception circuit 81 serving as a part of the measurement value determination unit 88 mixes the measurement signal Tx and the reflection signal Rx to generate an IF signal (IF: intermediate frequency) as the mixed signal Mx.

[0091] The IF signal (intermediate frequency signal) has a waveform including a high frequency component derived from the frequency of the 60 GHz band of the measurement signal Tx and the reflection signal Rx and a low frequency component corresponding to the frequency difference ΔF between the measurement signal Tx and the reflection signal Rx. The IF signal is input to the low pass filter 86, and a low frequency waveform according to the frequency difference ΔF is extracted. The extracted low frequency waveform is input to the analog-to-digital converter 87. The analog-to-digital converter 87 converts the low frequency waveform into a digital value and outputs the digital value to the signal processing unit 89.

[0092] The signal processing unit 89 serving as a part of the measurement value determination unit 88 converts the low-frequency waveform output from the analog-to-digital converter 87 into a frequency signal Px by fast Fourier transform processing or the like. The frequency signal Px is a signal indicating the intensity of the wave of each frequency, and a target peak value PS originating from the reflection signal Rx due to the reflection of the measurement signal Tx at the interface 74 appears in the frequency signal Px. The frequency corresponding to the target peak value PS is the frequency difference ΔF between the measurement signal Tx and the reflection signal Rx. The signal processing unit 89 sends the frequency signal Px to the frequency signal Px. Figure 4 The computing unit 64.

[0093] The calculation unit 64 serving as a part of the measurement value determination unit 88 calculates the values ​​of the distance YA and the level Y based on the frequency signal Px. When calculating the values ​​of the distance YA and the level Y, the calculation unit 64 refers to the information stored in the storage unit 63. For example, the storage unit 63 stores the correspondence between the frequency difference ΔF and the distance YA, the value for calculating the level Y from the distance YA (container information, such as the height of the container 70), and the like.

[0094] After calculating the frequency difference ΔF corresponding to the target peak value PS of the frequency signal Px, the calculation unit 64 calculates the values ​​of the distance YA and the level Y based on the frequency difference ΔF and the information stored in the storage unit 63. In this way, the calculation unit 64, which serves as a part of the measurement value determination unit 88, determines the level Y of the object 72 based on the intermediate frequency signal. The calculation unit 64 sends the calculated value of the level Y to the output unit 66. The output unit 66 changes the display content of the display unit 20 and the light emission state Y of the status lamp 52 according to the value of the level Y. In addition, the value of the level Y is sent to the management device 90 ( Figure 3 ). The output unit 66 can output a binary or multi-value control signal based on the comparison result between the calculated value of the level Y and the threshold value to the management device 90 through the external output terminal 12D. In addition, instead of the value of the level Y itself, a signal indicating a specific control to be performed according to the state of the level Y can be sent to the management device 90. For example, when the level Y is higher than a specific threshold value or lower than a specific threshold value, a signal indicating that the operation of a pump, a valve, etc. should be changed can be sent to the management device 90.

[0095] In addition, depending on the measurement environment, due to the presence of factors other than the interface 74 of the object 72, other factors such as Figure 5 Peaks other than the target peak PS shown. Figure 3 As shown, the measurement signal Tx can be reflected by the object 73 (agitator, ladder, etc.) inside the container to generate an environmental signal R that is different from the reflection signal Rx from the interface 74. N Then, in the frequency signal Px, in addition to the target peak PS, there also appears the peak value due to the ambient signal R N Therefore, multiple peaks are generated in the frequency signal Px.

[0096] In this case, the calculation unit 64, the radar transmission / reception circuit 81, and the signal processing unit 89 serving as the measurement value determination unit 88 can determine a measurement value of a distance corresponding to each of the generated plurality of peaks. The measurement value of the distance corresponding to the peak indicates how far away from the level meter 10 the peak originates from the signal reflected. The distribution determination unit 911 can use the measurement signal Tx and the reflection signal Rx (including the ambient signal R N ) and the distance YA are used to determine a reception intensity distribution, which indicates the relationship between the intensity of the signal received by the level meter 10 and the distance from the level meter 10 at which the signal is reflected.

[0097] Figure 7 An example of a received intensity distribution as a graph is shown. Figure 7In the graph of FIG. 7 , a plurality of peak candidates (which may be peaks of the target peak PS originating from the interface 74 of the object 72) appear. The environmental peak P as a peak candidate other than the target peak PS N The ambient signal R resulting from reflection at a portion other than the interface 74 of the object 72 N .

[0098] The extraction unit 912 extracts the peak position and peak intensity of each peak from the received intensity distribution determined by the distribution determination unit 911. The peak position corresponds to the distance of the element (e.g., the interface 74 of the object 72, the object 73 built in the container, etc.) that reflects the measurement signal Tx in the container 70 from the level meter 10. In addition, the peak intensity corresponds to the intensity of the reflection signal Rx generated due to the reflection of the measurement signal Tx. In addition, in the following, the reflection signal Rx reflected by the interface 74 and the environmental signal Rx reflected by the object 73 built in the container, etc. are referred to as N They can be collectively referred to as reflected signals Rx.

[0099] The candidate determination unit 913 extracts multiple combinations of peak positions and peak intensities and determines these combinations as multiple peak candidates. The peak candidates include the target peak PS originating from the interface 74 of the object 72 and the environment peak P originating from the object 73 in the container. N Then, the plurality of peak candidates determined by the candidate determination unit 913 based on the received intensity distribution are displayed on the display unit 20. The user selects the target peak PS corresponding to the position of the interface 74 of the object 72 (the distance from the level meter 10) from the plurality of peak candidates.

[0100] By appropriately performing calculations, the measurement value determination unit 88 can remove peak candidates other than the target peak PS from the reception intensity distribution, and determine the distance YA or the horizontal height Y of the storage object 72 based on the target peak PS. For example, the measurement value determination unit 88 can remove peak candidates other than the target peak PS from the reception intensity distribution by performing mask processing and background processing on the reception intensity distribution. By removing peak candidates other than the target peak PS from the reception intensity distribution, the measurement value determination unit 88 can determine the measurement value of the object 72 based only on the target peak PS. Then, even when the measurement signal Tx is reflected by an element other than the object 72 (such as the container built-in object 73) and generates the environmental signal R N In an environment such as , the measurement value determination unit 88 can also correctly determine the measurement value of the object 72. In addition, when the environment peak P is removed, N When unnecessary information is collected, users do not need to understand the information based on the measured signal Tx, reflected signal Rx, and environmental signal R NTherefore, the user can complete the setting of the measurement conditions required for the measurement of the horizontal height Y by a simple operation of selecting the target peak value PS from the given options.

[0101] (Mask Processing)

[0102] For example, a peak value (the environmental peak value P at the right end of the figure) appears at a position far away from the level meter 10. N ) may originate from a signal reflected at the bottom of the container 70. In order to remove the peak of the signal originating from the reflection at the bottom of the container 70, the signal generated at a position where the distance from the level meter 10 is close to the distance from the bottom may be ignored.

[0103] In addition, a peak value (the environmental peak value P at the left end in the figure) appears at a position with a small distance from the level meter 10. N ) may originate from internal reflection at a close distance from the level gauge 10. In order to remove the peak originating from the internal reflection at a close distance, the signal emitted at a position at a small distance from the level gauge 10 may be ignored.

[0104] So, for example, Figure 7 As shown, in the received intensity distribution, the area with a large distance from the level meter 10 and the area with a small distance from the level meter 10 can be set as the mask area W. A When determining the measurement value associated with the object 72, the measurement value determination unit 88 ignores the mask area W A The distance to set as the mask area W can be calculated in advance based on, for example, data on the installation environment of the level meter 10 (the height of the container 70, etc.). A data.

[0105] (Background processing)

[0106] In addition, the container-built-in object 73 always exists at a fixed position in the container 70. Therefore, regardless of the fluctuation of the level Y of the object 72 in the received intensity distribution, the ambient signal R reflected by the container-built-in object 73 N The environmental peak value P N Therefore, in order to remove the ambient signal R N The environmental peak value P N , the environmental peak value P N The waveform data is determined as the background signal W B , and the background signal W in the waveform data included in the received intensity distribution can be ignored B The waveform data matches or approximates the waveform data.

[0107] For example, by subtracting the background signal W from the waveform data of the reception intensity distribution determined by the distribution determination unit 911 B The waveform data is obtained by removing the ambient peak value P from the received intensity distribution. N When one of the peak candidates is designated as the target peak PS, the background signal W is obtained from the received intensity distribution. B For example, the level meter 10 enables the user to select a target peak value PS from a plurality of peak candidates. The measurement value determination unit 88 may store waveform data other than the selected target peak value PS among the peak candidates appearing in the reception intensity distribution in the storage unit 63 as the background signal W B Note that the level meter 10 can also obtain the background signal W by performing measurement in advance in a state where there is no object 72 (in a state where the container 70 is empty). B Waveform data.

[0108] (Tracking Processing)

[0109] Furthermore, in the case where mask processing or background processing is performed, the position of the target peak PS may enter the mask area W A , or the waveform of the target peak PS may be similar to the background signal W B Even in this case, it is preferable to perform tracking processing of the target peak value PS so that the measurement value determination unit 88 can determine the measurement value of the object 72.

[0110] The level Y of the object 72 changes continuously in the container 70 and is unlikely to fluctuate rapidly. Therefore, even if the position of the target peak PS enters the mask area W A Or the waveform of the target peak PS becomes close to the background signal W B In the case of a waveform of, if the value of the horizontal height Y has just been measured not long ago, the current horizontal height Y is expected to be close to the immediately previous measurement value. Therefore, when the target peak PS is lost during measurement, the measurement value determination unit 88 performs measurement by estimating the target peak PS close to the lost position (the distance from the level meter 10) through tracking processing. For example, the measurement value determination unit 88 can estimate the current position of the target peak PS based on the position immediately before the target peak PS is lost and the time change rate of the target peak PS until immediately before the target peak PS. Then, as a result of the target peak PS continuing to fluctuate, when the target peak PS passes through the mask area W A and background signal W B , a new peak appears near the position of the estimated target peak PS, and therefore the measurement value determination unit 88 can perform measurement with the new peak as the target peak PS.

[0111] Preferably, the user can set how long the measurement value determination unit 88 performs tracking processing when the target peak PS is lost during measurement and how long the estimated position of the target peak PS is continuously estimated. A and background signal W B In the case where the horizontal height Y is maintained at a constant value in the area, the tracking process can be set not to be released as time passes.

[0112] (Strength priority and close distance priority)

[0113] In addition, in the case where there are multiple peaks within the range of the distance between the position of the target peak PS and the level meter 10, it is possible to select which peak to regard as the target peak PS from several methods. For example, there is an intensity priority method in which a signal with high intensity (signal amplitude) is preferentially regarded as the target peak PS, and a close distance priority method in which a peak at a position with a small distance (close distance) from the level meter 10 is regarded as the target peak PS. Basically, the intensity priority method is preferably selected, but for example, in the case where the measurement signal Tx is reflected multiple times between the interface 74 and the inner wall of the container 70, peaks with high intensity originating from the interface 74 are generated at multiple positions. In this case, since the peak at the close distance with a small distance is considered to correspond to the first reflection at the interface 74, the peak at the close distance can be regarded as the target peak PS. Preferably, the user can set which one of the intensity priority and the close distance priority is selected.

[0114] Next, we will refer to Figure 8The state transition of the level meter 10 is described. First, when the level meter 10 is activated, the initial setting 100 is started. In the initial setting 100, various setting screens for sequentially setting the operating conditions of the level meter 10 including container information (the height of the container 70, etc.) and the level setting value (the value of the level Y, such as a threshold value) are sequentially displayed on the display section 20. Note that in the initial setting 100, the operating conditions of the level meter 10 can be set, such as whether the level meter 10 outputs an analog signal for a measured value or performs serial communication with an external device. On the other hand, there may be operating conditions that are not displayed in the initial setting 100 and are not set by the user. For example, an operating condition that one of the terminals included in the external output terminal 12D outputs an analog value can be predetermined regardless of the user's operation. In addition, an operating condition that automatically performs communication with an external device according to an external device connected to the level meter 10 can be predetermined. For example, when the level meter 10 is connected to a device (host device) that manages the level meter 10 , communication between the level meter 10 and the host device may be automatically performed by IO link communication defined in IEC61131-9 (IEC: International Electrotechnical Commission).

[0115] When the initial setting 100 is completed, the level meter 10 enters the measurement mode 500. In the measurement mode 500, the level meter 10 measures the level Y of the object 72. In the measurement mode 500, Figure 1 As shown, the relative position of the level setting value with respect to the container 70 is displayed on the display section 20 together with the bar display 22 .

[0116] In the measurement mode 500, the display section 20 may display a menu screen 600. The display screen of the measurement mode 500 for displaying the bar display 22 and the menu screen 600 may be switched to each other. For example, each time the user operates the menu key 32 in the measurement mode 500, the display content of the display section 20 is preferably switched between the display screen of the measurement mode 500 and the menu screen 600.

[0117] Fig. 9 An example of a menu screen 600 is shown. A plurality of options corresponding to individual setting contents are displayed on the menu screen 600. In response to the user's selection, the display content of the display section 20 changes from the menu screen 600 to an individual setting screen such as a container setting screen 610 ( Fig. 9 ), a setting value change screen 620, a miscellaneous setting screen 630, and an adjustment function 800. The menu screen 600 and the individual setting screen can be switched to each other. For example, when the menu key 32 and the up key 36 are operated simultaneously on the individual setting screen, the display unit 20 preferably returns to the menu screen 600.

[0118] When the character string "adjustment function" is selected on the menu screen 600, the level meter 10 starts the adjustment function 800. Various types of processing included in the adjustment function 800 can be realized by the calculation unit 64 executing a program stored in the storage unit 63, for example. Fig.10 The state transition of the level meter 10 in the adjustment function 800 is shown. When the adjustment function 800 is started, the level meter 10 first displays the current value display screen 801 in the display section 20. The current value displayed on the current value display screen 801 is a measurement value related to the horizontal height Y determined by the measurement value determination unit 88 at that time. For example, the measurement value determination unit 88 sets the peak position with the strongest intensity among the combinations of the peak position and the peak intensity (peak candidates) determined by the candidate determination unit 913 as the measurement value related to the horizontal height Y. The peak position with the strongest intensity corresponds to a value of the distance from the level meter 10 to the interface 74 of the object 72, for example. However, at this time, the distance of elements other than the interface 74 (such as the container built-in object 73) may also be displayed.

[0119] In addition, the current value display screen 801 can be transformed into the adjustment mode selection screen 810. On the adjustment mode selection screen 810, the user selects whether the process for removing peak candidates other than the target peak PS from the reception intensity distribution and determining the correct measurement value associated with the object 72 is performed in the optimization mode 820 or the restricted mode 860. In both the optimization mode 820 and the restricted mode 860, the user selects which of the multiple peak candidates is the target peak PS originating from the object 72. Then, in the optimization mode 820, diagnosis and setting optimization are performed. Specifically, diagnosis related to the measurement environment of the measurement value (such as the horizontal height Y) related to the object 72 is performed based on the reception intensity distribution. According to the diagnosis result, an advisory message indicating guidance on the measurement environment is displayed on the display unit 20. In addition, in the optimization mode 820, optimization of the settings required to determine the measurement value related to the object 72 (for example, the settings of the tracking process) is performed based on the target peak PS selected by the user and the diagnosis result.

[0120] On the other hand, in the limited mode 860, only learning based on the designation of the target peak PS by the user is performed. Learning is a setting related to the reception intensity distribution performed based on the designated target peak PS, and as a specific example, is a setting for removing peak candidates other than the target peak PS from the reception intensity distribution (for example, the mask area W A , background signal W B In the restricted mode 860, no other setting changes are performed.

[0121] Fig.11820 is a flowchart showing the flow of processing in the optimization mode 820. When the optimization mode 820 starts, first, in step 821, a plurality of peak candidates are determined (detected as candidates) by the candidate determination unit 913.

[0122] When the determination of the peak candidates is completed, in step 822 , a process (candidate selection) is performed to cause the user to select one of the plurality of peak candidates as the target peak PS originating from the object 72 to be measured.

[0123] In the process of selecting the candidate, the display unit 20 displays information about the reception intensity and the measurement value corresponding to each peak candidate. Referring to the measurement value, the stability of the reception intensity, etc., the user selects the peak candidate that appears to represent the measurement value (the distance from the level meter 10) of the object 72 to be measured as the target peak PS. For example, if the user knows the design value (height, etc.) of the container information of the container 70, the user can distinguish the peak candidates originating from the inner surface of the container 70 or the object 73 built in the container from the target peak PS originating from the object 72. In addition, for example, in the case where the object 72 is a liquid and its liquid level is shaken, the user can estimate that the target peak is a peak with unstable signal strength. Here, the options of "empty state" and "not applicable" are also displayed on the display unit 20. In the case where the object 72 is not stored in the container 70 (the container 70 is empty), the user can select the option of "empty state". Note that the distance from the level meter 10 to the bottom of the container 70 can also be described in the option of "empty state". Furthermore, when considering that none of the displayed peak candidates represents the measurement value of the storage object 72 to be measured, the user may select an option of “Not Applicable”.

[0124] In step 823, it is determined whether the "Not Applicable" option has been selected. When the "Not Applicable" option is selected ("Yes" in step 823), in step 840, the level meter 10 displays a suggestion message in the display section 20. The suggestion message of step 840 indicates that the level meter 10 has not yet been able to find the interface 74 of the object 72 by measuring and suggestions for improving the measurement environment. For example, the display section 20 displays a message such as "No liquid level signal found, please increase the sensitivity setting or check the installation." After displaying the suggestion message of step 840, the level meter 10 ends the optimization mode 820 without learning and setting the optimization.

[0125] Then, in Fig.11 In step 823, when the “Not Applicable” option is not selected (“No” in step 823), that is, when any one of the peak candidates determined by the candidate determination unit 913 is selected as the target peak PS, the processing of the optimization mode 820 proceeds to step 825.

[0126] In step 825, a diagnosis is performed on the measurement environment based on the target peak value PS and the received intensity distribution. Specifically, the selected target peak value PS and the environmental signal R N For example, if the signal strength of the peak candidate selected by the user is extremely weaker than the signal strength of other peak candidates, it is determined whether there is a problem with the relationship between the ambient signal R N There is a problem with the relationship between the ambient signal R N If there is a problem in the relationship (“No” in step 825 ), a suggestion message is displayed on the display unit 20 in step 827 .

[0127] The advice message displayed in step 827 indicates that the environmental signal R N The influence on the measurement of the level meter 10 is greater. That is, it is suggested that the intensity of the target peak PS may be affected by the ambient signal R N Therefore, the advice message of step 827 advises that the installation of the level meter 10 itself should be checked. After the advice message is displayed in step 827, the level meter 10 learns the user's specified value as the target peak value PS, and ends the optimization mode 820.

[0128] On the other hand, when the ambient signal R N In the case where there is no problem with the relationship between ("Yes" in step 825), the level meter 10 proceeds to step 828, and calculates the close-range measurement limit by using the intensity of the peak candidate selected by the user, the peak not selected from the peak candidates appearing at the close distance of the level meter 10, and the reflection data that may be generated from objects other than the object 72 at the close distance (for example, stray signal waves caused by internal reflection of the container 70, etc.). In the calculation of the close-range measurement limit, the limit on the close-range side (how far the measurement can be performed) is confirmed by the level meter 10 for the measurement range. The reflection signal Rx from a position too close to the level meter 10 may include the influence of internal reflection such as the container 70, so that a valid measurement value is obtained from a position slightly away from the level meter 10.

[0129] Then, in step 829, it is confirmed (diagnosed) whether there is a problem in the calculation result of the close distance measurement limit. For example, the calculated value of the close distance measurement limit is displayed on the display unit 20, and the user selects a distance as the limit on the close distance side of the measurement range.

[0130] In the case where there is a problem in the calculation result of the close distance measurement limit (No in step 829), the process in the optimization mode 820 proceeds to step 830, and an advice message about the result of the distance measurement is displayed on the display section 20. In the advice message of step 830, for example, it is displayed that the sensitivity setting of the close distance measurement should be increased, the installation of the level meter 10 should be checked, etc.

[0131] On the other hand, in the case where there is no problem in the calculation result of the close-range measurement limit ("Yes" in step 829), the processing in the optimization mode 820 proceeds to step 831, and the optimization processing of the measurement conditions is started. After the optimization processing is completed, in step 832, a screen indicating the completion of the optimization processing is displayed on the display unit 20, and the optimization mode 820 is completed.

[0132] In step 831, a diagnosis related to the measurement environment is performed based on the selected target peak PS and the received intensity distribution. Then, optimization of the settings required to determine the measurement value related to the object 72 is performed based on the diagnosis result. In the diagnosis related to the measurement environment, it is estimated whether there is an element reflecting the measurement signal Tx other than the object 72 in the container 70, and the position where the element exists when the element exists. It is assumed that the selected target peak PS is a reflection signal Rx obtained by reflecting the measurement signal Tx by the object 72 to be measured, and the environment peak PS is N is the environmental signal R obtained by reflecting the measurement signal Tx from an element other than the object 72. N Therefore, the target peak value PS and the environment peak value P in the receiving intensity distribution can be N In the optimization of the settings required for determining the measurement value related to the object 72, the measurement conditions required for the level meter 10 to continuously specify the position of the target peak PS included in the received intensity distribution during the measurement are set. For example, in addition to setting the mask area W A and background signal W B In addition, it also performs setting intensity priority and close distance priority when selecting the peak position, as well as setting the tracking duration and range of the estimated position.

[0133] Fig.12 The setting contents according to the diagnosis result (the state of the measurement environment) are shown. Fig.12 Items “Peak Selection”, “Tracking”, and “Learning” indicating the contents of settings to be applied are shown. The item “Peak Selection” is a setting of which peak is preferentially regarded as the target peak PS in the case where there are multiple peaks (for example, intensity priority or close distance priority). The item “Tracking” is a setting of whether it is recommended to terminate the tracking process of searching for a peak near the lost position in a short time or to continue the tracking process for a long time in the case where the level meter 10 loses the target peak PS. In addition, the item “Learning” is a setting of whether it is recommended to store (learn) data required for removing peak candidates other than the target peak PS, such as a mask area W about the received intensity distribution. A and background signal W B data.

[0134] For example, when the intensity of the expected target peak PS is stronger than that of other peak candidates (environmental peak P N ) intensity, the intensity of “Peak Selection” is set to “Intensity Priority Recommendation”. A and background signal W B In the case of maintaining a long period of time, the item "tracking" is set to "long-term recommendation". In the level meter 10, the target peak value PS can be specified without removing the ambient peak value P N In this case, the item "Learning" is "Not Executed".

[0135] exist Fig.12 , the state of the measurement environment (diagnosis result) is classified into state A, state B, state C, etc., and appropriate setting contents are predetermined for each state. By applying the predetermined appropriate setting contents, optimization of the settings required for determining the measurement value related to the distance or horizontal height Y of the object 72 is automatically performed. For example, if the state of the measurement environment is "A", setting contents are applied such that the setting of the peak selection is "intensity priority recommendation", the setting of the tracking is "short time recommendation", and the setting of the learning is "execution". Note that, as Fig.12 As shown, depending on the state, the setting for peak selection may be "short distance priority recommendation", the setting for tracking may be "long time recommendation", or the setting for learning may be "execution".

[0136] When the optimization mode 820 ( Fig.11 ), the setting items related to the measurement of the horizontal height Y, especially the setting items related to "peak selection", "tracking" and "learning", are automatically set. Since these settings are automatically performed by the level meter 10, the user's operation only selects the horizontal height candidate corresponding to the target peak PS, and it is not necessary to set each setting item in detail. In addition, in the case where the measurement environment is not appropriate in the optimization mode 820, a suggestion message for improving the measurement environment is displayed on the display unit 20. By checking the suggestion message, the user can grasp the work to be performed (for example, checking the installation state of the level meter 10) in order to correctly perform the measurement. Therefore, the level meter 10 of the present embodiment is very convenient for the user.

[0137] However, since the setting items of automatic setting are only "recommended", it may not be the optimal setting depending on the measurement environment. Therefore, it is preferable that various setting items can be changed according to the user's desire. For example, when Fig. 9When an option (character string "settings") on the miscellaneous setting screen 630 is selected on the menu screen 600 in , a screen for changing various measurement conditions including setting items such as "peak selection" and "tracking" is preferably displayed on the display section 20. In addition, optimization of settings required to determine the measurement value related to the distance or horizontal height Y of the object 72 can be performed in a question-and-answer format (wizard format) according to the user's wishes. Specifically, questions about the measurement conditions of the horizontal height Y (for example, container information about the size of the container 70, questions about the presence or absence of the object 73 built in the container, etc.) are displayed on the display section 20, and the user inputs answers to the questions. Then, the measurement value determination unit 88 performs optimization of settings required to determine the measurement value related to the distance or horizontal height Y of the object 72 based on the input answer.

[0138] Next, we will describe Fig.10 A case where the restricted mode 860 is selected on the adjustment mode selection screen 810. Fig.13 860 is a flowchart of the processing flow in the limited mode 860. When the limited mode 860 starts, first, in step 861, a screen indicating whether there is an existing learning execution result (execution result presence / absence display) is displayed on the display section 20.

[0139] A plurality of options are displayed on the screen of the execution result presence / absence display. The options in the execution result presence / absence display include an option (“Return”) to return to the previous screen (adjustment mode selection screen 810) and an option (“Execute”) to execute learning. In the case where there is an existing learning execution result (a step for removing the environment peak value P has been completed), N The mask area W A , background signal W B In the case of a setting such as ", a display indicating that there is an existing learning result (for example, "Learning execution result: exists") is performed. In addition, in the case where there is an existing learning execution result, an option to erase the existing learning execution result ("erase") is also included in the options in the execution result existence / non-existence display. When the user selects the "erase" option in step 861 (for example, operating the menu key 32 while the "erase" option is displayed), the processing of the restricted mode 860 proceeds to step 862.

[0140] In step 862, a screen for confirming whether to actually erase the existing learning execution result (erasure necessity confirmation) is displayed on the display unit 20. In step 862, the user selects whether to execute erasure of the existing learning execution result. In the case where the user selects not to execute erasure ("No" in step 862), the display of the display unit 20 returns to the screen for displaying the presence / absence of the execution result (returns to step 861).

[0141] When the user selects to erase the existing learning execution result in step 862 (“Yes” in step 862), the processing of the limited mode 860 proceeds to step 863, and the information about the target peak PS that has been selected and the information for removing the peak candidates other than the target peak PS from the reception intensity distribution (mask area W A , background signal W B When the existing learning execution result is erased, the processing in the restricted mode 860 returns to step 861.

[0142] When the user selects the "Execute" option in step 861, learning starts. When learning starts, the process of the limited mode 860 proceeds to step 864, and a process (candidate selection) is performed to make the user select one of the multiple peak candidates determined by the candidate determination unit 913 as the target peak PS originating from the object 72 to be measured.

[0143] Among the candidate selections of step 864 of the restricted mode 860, the same selections as those of step 822 ( Fig.11 ) The screen for candidate selection may include options of "Not Applicable" and "Empty State".

[0144] After the candidate selection in step 864, it is determined whether the option of "Not Applicable" has been selected in step 865. In the case where the option of "Not Applicable" is selected ("Yes" in step 865), a process of inputting a numerical value is performed in step 866. In the process of inputting a numerical value, the user specifies and inputs the current numerical value of the measurement value of the object 72 to be measured.

[0145] After performing numerical input in step 866, or when the "Not Applicable" option is not selected ("No" in step 865), that is, when any one of the peak candidates determined by the candidate determination unit 913 is selected as the target peak PS, processing of the restricted mode 860 proceeds to step 867.

[0146] In step 867, the peak at the peak position of the peak candidate selected by the user or the numerical value input by the user is stored as the target peak PS, and settings for removing other peak candidates from the received intensity distribution (for example, mask area W) are performed. A , background signal W B Then, a screen indicating that the learning is completed is displayed on the display unit 20, and the restricted mode 860 is completed.

[0147] In the case of limited mode 860, default settings predetermined in initial settings 100 or the like are applied as measurement conditions, including setting items such as "peak selection" and "tracking" automatically set in optimization mode 820. The user can manually change the measurement conditions from menu screen 600 or the like as needed.

[0148] In both the optimization mode 820 in which diagnosis and setting optimization are performed and the limited mode 860 in which only learning is performed, the setting (for example, mask area W) for removing peak candidates other than the target peak PS from the reception intensity distribution is automatically performed by the measurement value determination unit 88. A , background signal W B For example, when the user selects the target peak PS, the measurement value determination unit 88 uses the waveforms of the peak candidates (except the selected target peak PS) appearing in the reception intensity distribution as the background signal W B The waveform of is stored in the storage unit 63. When the measurement value determination unit 88 determines the measurement value of the object 72, the background signal W is removed from the received intensity distribution. B The waveform of the object 72 is obtained by measuring the target peak value PS, and the distance or the horizontal height Y of the object 72 from the level meter 10 is determined based on the target peak value PS.

[0149] If the setting for removing the peak candidates other than the target peak PS from the reception intensity distribution is automatically performed, when removing the peak candidates such as the environment peak PS N When unnecessary information is collected, the user does not need to know the information based on the measured signal Tx, the reflected signal Rx, and the environmental signal R N Therefore, the user can complete the setting of the measurement conditions required for the measurement of the horizontal height Y by a simple operation of selecting the target peak value PS from the given options.

[0150] Note that after the target peak PS is selected in the optimization mode 820 or the limited mode 860 and until the information about the target peak PS is erased, only the information about the measurement value and the reception intensity corresponding to the target peak PS may be displayed as the peak candidate, so that it can be confirmed that the peak candidates other than the target peak PS are removed from the reception intensity distribution. For example, when the adjustment function 800 is executed again after the target peak PS is selected and a screen for selecting a peak candidate is displayed on the display section 20, only the information of the selected target peak PS may be displayed as the peak candidate.

[0151] Next, the following will describe the Fig.10 Specific examples of individual display screens displayed on the display unit 20 in the adjustment function 800 of FIG. In the description of the specific examples of the display screens, the detailed description of the processing performed on each screen can be simplified. In addition, the order of explanation of the screens is not necessarily consistent with the order of processing. First, Fig.14Shown as Fig.10 The optimization mode selection screen 810a and the restricted mode selection screen 810b of the adjustment mode selection screen 810 are shown. In addition to the distance value (here 800mm) measured by the level meter 10, the optimization mode selection screen 810a and the restricted mode selection screen 810b also include an interface position icon 131 and a receiving intensity scale 890. In addition, a selection bar 891 for displaying options is displayed at the lower part of the current value display screen 801. On the optimization mode selection screen 810a, a character string "Execute diagnosis and set optimization" is displayed in the selection bar 891. On the restricted mode selection screen 810b, a character string "Execute learning only" is displayed in the selection bar 891. When the user operates the down key 35 or the up key 36, the display of the selection bar 891 is switched.

[0152] The interface position icon 131 includes a graphic 131a ( Fig.14 ), a graphic 131b imitating the container 70 and a line 131c indicating the interface 74 of the object 72 (which is arranged below the graphic 131a), and an arrow 131d extending from the graphic 131a imitating the level meter 10 to the line 131c of the interface 74. In the graphic 131b imitating the container 70, the line 131c indicating the interface 74 is displayed at a position corresponding to the ratio of the size of the measured value relative to the size of the entire container 70 (the height of the container 70). The interface position icon 131 visually and understandably shows the user that the displayed measured value indicates the distance from the level meter 10 to the interface 74 and the scale of the ratio of the distance to the size of the entire container.

[0153] The reception strength scale 890 indicates the intensity of the received signal received by the receiving circuit 43R for the reflected signal Rx or the ambient signal R N Information about the strength of the received radio wave (received strength), including the reflected signal Rx or the ambient signal R N The peak candidates on which the displayed measurement values ​​are calculated correspond to. For example, the intensity of the radio waves received by the receiving circuit 43R is classified into several levels (here, 4 levels), and the reflected signal Rx or the ambient signal R N The level of the intensity of, as a basis for calculating the displayed measurement value, is indicated by the number of the reception intensity scale 890. For example, if the reflected signal Rx or the ambient signal R N If the reflected signal Rx or the ambient signal R N When weak, the number of reception strength scales 890 displayed is small (at least one).

[0154] The number of the reception intensity scale 890 changes dynamically according to the intensity of the radio wave received by the receiving circuit 43R when it is displayed. Therefore, if the intensity of the radio wave received by the receiving circuit 43R is unstable, the number of the reception intensity scale 890 changes in a short period of time. Note that the information about the reception intensity only needs to be dynamically changed according to the size of the reception intensity, and can be displayed in a form different from the reception intensity scale 890. For example, the reception intensity can be displayed digitally, or the stability of the intensity can be displayed by characters such as "dynamic" (unstable) and "static" (stable).

[0155] Hereinafter, the interface location icon 131 and the reception intensity scale 890 may be displayed on other screens, but unless otherwise specified, descriptions and reference numerals regarding the interface location icon 131 and the reception intensity scale 890 on other screens are omitted.

[0156] When the menu key 32 is operated on the optimization mode selection screen 810a, the optimization mode 820 ( Fig.11 ), and when the menu key 32 is operated on the limited mode selection screen 810b, the limited mode 860 ( Fig.13 ).

[0157] In the optimization mode 820 and the restricted mode 860, while the processing in the processing unit 62 is being executed, the display unit 20 may display the Fig.15 For example, when the candidate determination unit 913 determines (detects candidates) a plurality of peak candidates in the optimization mode 820, the waiting screen 821 is displayed. An animated image is displayed on the waiting screen 821 to indicate that the processing in the processing unit 62 is waiting. For example, Fig.15 As shown, a plurality of quadrilaterals are displayed side by side, and an animation of the sizes of these quadrilaterals changing sequentially is displayed. The animation display is displayed each time the waiting process is performed, but the description thereof will be omitted below.

[0158] In optimization mode 820( Fig.11 ) before executing the candidate selection in step 822, the display unit 20 displays Fig.16 The candidate selection message is shown in . The candidate selection message prompts the user to select a numerical value representing the correct distance of the object 72 on the next screen.

[0159] When the menu key 32 is operated for the candidate selection message, the display unit 20 displays Fig.17 The candidate confirmation screen is shown. Fig.17The candidate confirmation screens include a first candidate confirmation screen 822a, a second candidate confirmation screen 822b, a third candidate confirmation screen 822c, a fourth candidate confirmation screen 822d, and a cancel screen 822e. When the down key 35 or the up key 36 is operated, these screens are switched to each other.

[0160] The first candidate confirmation screen 822a shows that the container 70 is in an empty state and the distance (here, 1500 mm) from the bottom of the container 70 in the empty state. The indication of the empty state is displayed in the selection bar 891 at the bottom of the screen. Information indicating the signal strength is not displayed on the first candidate confirmation screen 822a. In addition, the arrow included in the interface position icon 131 reaches the bottom of the graphic indicating the container 70.

[0161] The second candidate confirmation screen 822b displays the peak position (distance) value "800 mm" of the peak candidate, the interface position icon 131, and the reception strength scale 890. The peak position value is displayed in the selection field 891. The reception strength scale 890 of the second candidate confirmation screen 822b has four scales (signal strength).

[0162] The third candidate confirmation screen 822c displays the peak position value "1490 mm" of the peak candidate, the interface position icon 131, and the reception strength scale 890. The reception strength scale 890 of the third candidate confirmation screen 822c has three scales (signal is slightly weak).

[0163] On the fourth candidate confirmation screen 822d, a character string "Not applicable" is displayed instead of the value of the peak position in the selection field 891. In the case where the user considers that any peak candidate is not suitable as the position of the interface 74 of the object 72, the fourth candidate confirmation screen 822d is selected. Information indicating the signal strength is not displayed on the fourth candidate confirmation screen 822d. In addition, no arrow is displayed on the interface position icon 131.

[0164] In the cancel screen 822e, the selection bar 891 includes a character string "Return". The information indicating the signal strength and the interface position icon 131 are not displayed on the cancel screen 822e. When the menu key 32 is operated on the cancel screen 822e, the display of the display unit 20 returns to the adjustment mode selection screen ( Fig.14 ).

[0165] The user selects one of the peak candidates as the target peak PS by operating the menu key 32 on a screen indicating the peak position of the peak candidate considered to correspond to the target peak PS (e.g., the second candidate confirmation screen 822b and the third candidate confirmation screen 822c). In the case where the fourth candidate confirmation screen 822d (not applicable) is selected in the optimization mode 820, an advice message indicating that no liquid level signal is found and advice for improving the measurement environment are displayed on the display unit 20.

[0166] Fig.18 shows the user selected target peak PS and ambient signal R N Suggested message if there is a problem with the relationship between Fig.11 The suggestion message suggests that the environmental signal R N The influence relative to the measurement of the level meter 10 is large, and it is suggested that the installation of the level meter 10 itself should be checked.

[0167] Fig.19 The calculation result confirmation screen for the close-range measurement limit is displayed ( Fig.11 The calculation result confirmation screen of the close-range measurement restriction can be switched between the result negation screen 829a and the result approval screen 829b by operating the down key 35 or the up key 36. When the menu key 32 is operated on the result negation screen 829a, there is a problem in the calculation result of the close-range measurement restriction. When the menu key 32 is operated on the result approval screen 829b, there is no problem in the calculation result of the close-range measurement restriction.

[0168] Fig. 20 830a (shown as a suggestion message in the case where the calculation result of the close distance measurement limit is not optimal) Fig.11 830 in step 830). The advice message 830a displayed here advises that the installation of the level meter 10 should be checked. Then, the advice message 830a advises to increase the close distance sensitivity setting (to set the sensitivity to high).

[0169] Fig.21 The optimization process start confirmation screen is shown. This screen is displayed when the optimization process starts. Fig.11 By operating the down key 35 or the up key 36, the optimization process start confirmation screen can be switched between the start confirmation screen 831a and the start negation screen 831b. When the menu key 32 is operated on the start confirmation screen 831a, the optimization process is started. When the menu key 32 is operated on the start negation screen 831b, the optimization process is canceled, and the display of the display unit 20 returns to the adjustment mode selection screen ( Fig.14 ).

[0170] Fig. 22The optimization completion screen is shown. This screen is displayed when the optimization process is completed ( Fig.11 The optimization completion screen displays the detection settings (measurement conditions) that have been optimized and which settings have been specifically performed by the optimization. Fig. 22 It shows that learning is performed, the peak selection mode is set to "short distance priority", and tracking is performed for a long time. Since the display content of the optimization completion screen has a large amount of information, the display unit 20 may not be able to display all the information together in one screen. In this case, the display content of the optimization completion screen can be scrolled by operating the down key 35 or the up key 36. Then, when all the display content to be displayed is displayed and the scroll reaches the bottom, "OK" is displayed on the display unit 20. When the menu key 32 is operated in the state where "OK" is displayed, the optimization is completed, and the display of the display unit 20 returns to the adjustment mode selection screen ( Fig.14 ).

[0171] Next, Fig.23 A display screen showing the presence or absence of a learning execution result in the limited mode 860 ( Fig.13 Step 861 in the figure). There are three types of display screens for the presence or absence of learning execution results: a cancel selection screen 861a, an erase selection screen 861b, and a learning execution selection screen 861c. These screens include a display indicating that there is an existing learning execution result ("Exists"). In the case where there is no existing learning execution result, a display such as "None" is performed. The cancel selection screen 861a, the erase selection screen 861b, and the learning execution selection screen 861c differ from each other in the character strings displayed in the selection bar at the bottom of the screen ("Return", "Erase", and "Execute", respectively). These screens can be switched to each other by the user operating the down key 35 or the up key 36. When the menu key 32 is operated when the selection bar is in the "Return" state (cancel selection screen 861a), the display of the display unit 20 returns to the adjustment mode selection screen ( Fig.14 ).

[0172] Fig.24 The erasure necessity confirmation screen showing the learning execution result ( Fig.13 When the menu key 32 is operated while the selection bar indicating the presence or absence of the learning execution result on the display screen is in the "erase" state (erase selection screen 861b), the display of the display unit 20 is changed to the erase negation screen 862a.

[0173] In the selection column of the erasure negation screen 862a, a message indicating that the existing learning execution result does not need to be erased ("No") is displayed. When the menu key 32 is operated on this screen, the display of the display unit 20 returns to the erasure selection screen 861b. By operating the down key 35 or the up key 36, the erasure negation screen 862a can be changed to and from the erasure affirmation screen 862b.

[0174] In the selection column of the erase confirmation screen 862b, a message indicating that the existing learning execution result should be erased ("Yes") is displayed. When the menu key 32 is operated on this screen, the existing learning execution result is erased, and the display of the display unit 20 changes to the erase completion screen 863. The erase completion screen 863 shows that the existing learning execution result has been erased. When the menu key 32 is operated on the erase completion screen 863, the display of the display unit 20 changes to the erase selection screen 861b. However, after the learning execution result is erased, the existing learning execution result is displayed as "None" on the erase selection screen 861b.

[0175] Fig.25 The learning execution confirmation screen is shown. When the menu key 32 is operated on the learning execution selection screen 861c, the display of the display unit 20 changes to the execution confirmation screen 861d. By operating the down key 35 or the up key 36, the execution confirmation screen 861d can be switched to the execution denial screen 861e. When the menu key 32 is operated on the execution confirmation screen 861d, learning starts, and the peak candidate ( Fig.13 When the menu key 32 is operated on the execution denial screen 861e, the display of the display unit 20 returns to the learning execution selection screen 861c.

[0176] Similar to the optimization mode 820, in the restricted mode 860 as well, when a peak candidate is selected, the display unit 20 displays the peak candidate. Fig.17 Then, in the case where an option indicating "not applicable" is selected in the restricted mode 860 (the fourth candidate confirmation screen 822d), the display in the display unit 20 changes to the Fig.26 The numerical value input screen related to the distance shown in the figure. On the numerical value input screen, the user can continuously change the numerical value of the distance displayed in the selection column by operating the down key 35 or the up key 36. The user adjusts the displayed numerical value to an appropriate numerical value as the peak position of the target peak PS, and then operates the menu key 32 to input the distance value of the target peak PS.

[0177] Fig. 27 860 shows a learning completion screen in the restricted mode 860. This screen is displayed when learning is completed in the restricted mode 860 ( Fig.13When the menu key 32 is operated on this screen, the display of the display unit 20 returns to the adjustment mode selection screen ( Fig.14 ).

[0178] Next, we will refer to Fig.28 Another example of the level meter 10 is described. Fig.28 FIG. 1 is a perspective view showing another example of the level meter 10. Fig.28 In, with Figure 1 and Figure 2 The components of the level meter 10 in FIG. 1 are composed of components having the same functions as those of the level meter 10 in FIG. Figure 1 and Figure 2 The components in FIG. 1 are denoted by the same reference numerals, and their description will not be repeated unless necessary.

[0179] Fig.28 The housing 15 of the level meter 10 in the embodiment includes a base 15a and an end 21. The base 15a is arranged at one end side (lower side) in the longitudinal direction A (measurement axis direction) of the housing 15. The end 21 is arranged at the other end side in the longitudinal direction A. Fig.28 In the embodiment, the display portion 20 is provided in the terminal 21. In addition, the end portion 21 can be separated from the base portion 15a. The base portion 15a has a cylindrical shape, and the end portion 21 has a prism shape.

[0180] The end portion 21 can be fixed to the base 15a by a fastening screw relative to the back side of the display unit 20. In addition, a connection connector for transmitting electrical signals between the base 15a and the end portion 21 is preferably provided. For example, one of a pair of connection connectors can be provided on the base 15a, and the other of a pair of connection connectors can be provided on the end portion 21. Connecting a pair of connection connectors enables sending and receiving electrical signals between the base 15a and the end portion 21. In addition, when the end portion 21 is separated from the base 15a, the connection connector is connected between the base 15a and the end portion 21 via a cable for sending and receiving electrical signals. As a result, even in a state where the end portion 21 is separated from the base 15a, the display unit 20 can be displayed corresponding to the measured horizontal height Y. In this way, when the end portion 21 can be separated from the base 15a, the user can confirm the display of the display unit 20 at a position away from the base 15a. For example, in the case where the level meter 10 is provided at a position higher than the user's viewpoint, it may be difficult for the user to confirm the display of the display unit 20. Here, when the end portion 21 can be separated from the base 15 a , the user can easily confirm the display portion 20 at the location where the container 70 is installed by pulling the end portion 21 to the height of his / her viewpoint.

[0181] exist Fig.28 In the embodiment, the connection portion 12 is provided in a portion of the end portion 21 opposite to the display portion 20. By rotating the housing 15, the user can orient the connection portion 12 in a direction that is easy to handle.

[0182] In addition, Fig.28 In the embodiment, the status light 52 is provided on the outer peripheral surface of the base 15a in the housing 15. Therefore, Fig.28 The status light 52 in FIG. 1 is provided on one end side (lower side) in the longitudinal direction A relative to the display section 20. Fig.28 Although not shown in FIG. 1 , the status LED 50 of the status light 52 is provided inside the sensor unit 16 .

[0183] In addition to the up key 34 and the down key 35, Fig.28 The direction keys 33 in the figure also include a left key 38, a right key 37, and a center key 39. The user can easily switch the display mode of the display unit 20 by operating these keys, and can easily change various setting values ​​in the setting mode. In addition, operating the left key 38 can have a similar effect as operating the left key 38 at the same time. Figure 1 and Figure 2 The functions of the menu key 32 and the up key 36 in the level meter 10 are shown in FIG.

[0184] In the following, Fig.28 Some screens displayed on the display unit 20 of the level meter 10 will be described as follows. Figure 1 and Figure 2 Another example of each screen in the level meter 10. Fig.28 The display unit 20 of the level meter 10 is larger than Figure 1 and Figure 2 The display part 20 of the level meter 10 is formed in the display part 20, so there is a margin in the entire display space. Fig.29 Shows Fig.14 Another example of the adjustment mode selection screen. Fig.29 In the adjustment mode selection screen 810c, Fig.14 Compared to the display of , a sufficient interval is ensured between the interface position icon 131 and the display of the reception intensity scale 890 and the current value (here, 2800mm). In addition, a title bar 899 of "Adjustment Function" indicating that this screen is part of the adjustment function 800 is displayed in the upper part of the screen. Then, an option of "Perform diagnosis and setting optimization" indicating the optimization mode 820 and an option of "Perform learning only" indicating the restricted mode 860 are displayed below the adjustment mode selection screen 810c. The user moves the cursor 810d up and down by operating the up key 34 or the down key 35 to select one of the options. In this way, in Fig.29 On the adjustment mode selection screen 810c, the display of the options is not switched, but all selectable options are displayed together.

[0185] exist Fig.30 In, display Fig.17 Another example of a candidate confirmation screen. Fig.30 In the candidate confirmation screen 822z of FIG. 822, a plurality of options of peak positions (distances) of peak candidates (here, 1200 mm, 2000 mm, 2800 mm, and empty state: 3200 mm) are displayed together on one screen in the candidate display area 895 on the right side of the screen. The user moves the cursor 895a up and down by operating the up key 34 or the down key 35 to select one of the options. Therefore, the user does not need to Fig.17 Switch the display to confirm the candidate value. Fig.30 However, an option of "Not applicable" may also be displayed. A title bar 899 of "Adjustment function" is also displayed on the candidate confirmation screen 822z.

[0186] exist Fig.31 In, display Fig. 22 Another example of an optimization completion screen. Since there is a margin in the display space, the optimization setting contents are displayed together on one screen without performing the above steps. Fig. 22 The scrolling display shown is shown. Also on the optimization completion screen, a title bar 899 of "Adjustment Function" is displayed.

[0187] Next, we will refer to Fig.32 A further example of the level meter 10 is described. Fig.32 is a perspective view showing still another example of the level meter 10. Fig.32 In, with Figure 1 and Fig.28 The components of the level meter 10 in FIG. 1 are composed of components having the same functions as those of the level meter 10 in FIG. Figure 1 and Fig.28 The components in FIG. 1 are denoted by the same reference numerals, and their description will not be repeated unless necessary.

[0188] exist Fig.32 In the embodiment, the level meter 10 includes a sensor unit 16 and a remote controller 55, which can communicate with the sensor unit 16 at a location away from the sensor unit 16. Then, the sensor unit 16 and the remote controller 55 are connected by a communication cable 11. Fig.32 In the level meter 10 of FIG. 1 , only the sensor unit 16 is attached to the container 70 containing the object 72 , and the remote controller 55 communicates with the sensor unit 16 at a location away from the container 70 .

[0189] like Fig.32 As shown, the sensor unit 16 has a substantially cylindrical shape. The status light 52 is provided on the upper portion of the sensor unit 16. The remote controller 55 corresponds to Figure 1 and Fig.28The housing 15 of the level meter 10 in the sensor unit 16 includes a display unit 20 that performs display according to the measured horizontal height Y. The display unit 20 can display a bar display 22 and a color scale 24. In addition, the remote controller 55 includes an operation unit 30 for the user to operate the level meter 10. In addition, the remote controller 55 has a connection unit 12 as a connection terminal with an external device. The remote controller 55 also includes a remote status light 54. The remote status light 54 is lit in the same lighting state as the status light 52 of the sensor unit 16.

[0190] Fig.32 The display unit 20 of the level meter 10 is Figure 1 and Fig.28 The display unit 20 of the level meter 10 similarly displays various types of information. Fig.32 The information indicated to the user by the display unit 20 is equivalent to Figure 1 and Fig.28 The size of the display unit 20 can be simplified. Fig.32 The display content of the display unit 20 in .

[0191] In the following, Fig.32 Some screens displayed on the display unit 20 of the level meter 10 will be described as follows. Figure 1 and Fig.28 Another example of each screen in the level meter 10 is shown in FIG. Fig.33 is a diagram showing the adjustment function 800 ( Fig.10 ) is a diagram showing screen transitions of the display unit 20 of the remote controller 55 in the adjustment function 800. In the adjustment function 800, a character string is displayed on the display unit 20 of the remote controller 55 instead of the bar display 22 and the color scale 24. Due to display space, the interface position icon 131 and the reception intensity scale 890 are not displayed on the display unit 20 of the remote controller 55. In addition, only one line of the character string is displayed.

[0192] When the adjustment function 800 starts, first, a character string "adjustment function" is displayed on the display unit 20. When the menu key 32 is operated in this state, a cancel screen 800a showing a character string "return" is displayed on the display unit 20. When the menu key 32 is operated in this state, the adjustment function 800 is interrupted, and the display unit 20 returns to the normal measurement mode 500 as shown in FIG.

[0193] By operating the direction key 33, the display unit 20 can mutually switch between the cancel screen 800a, the optimization mode selection screen 810a, and the limited mode selection screen 810b. In the display unit 20 of the remote controller 55, the character string "Diagnosis / Optimization" indicates the optimization mode selection screen 810a. In addition, the character string "Learning Only" indicates the limited mode selection screen 810b.

[0194] When the menu key 32 is operated on the optimization mode selection screen 810a, the Fig.11 Here, as another example of the screen of the display unit 20, the candidate selection ( Fig.11 Another example of a screen in step 822 in FIG. 1 and a screen in which a suggestion message ( Fig.11 Another example of a screen of step 827 in FIG.

[0195] Before executing the candidate selection in step 822, a candidate selection message is displayed in the display unit 20 in the form of a character string "Select the correct distance". The message prompts the user to select a numerical value representing the correct distance of the object 72 on the next screen. When the menu key 32 is operated for the candidate selection message, a second candidate confirmation screen 822b is displayed on the display unit 20. The value "800mm" of the peak candidate is displayed on the second candidate confirmation screen 822b. By operating the direction key 33, the second candidate confirmation screen 822b can be switched to a third candidate confirmation screen 822c displaying the value "1000mm" of another peak candidate. In addition, although in Fig.33 Although not shown in the figure, by operating the direction key 33, the display section 20 can be changed to the first candidate confirmation screen 822a indicating that the container 70 is in an empty state and the fourth candidate confirmation screen 822d displaying the character string "Not applicable". When the menu key 32 is operated on any candidate confirmation screen, the displayed peak candidate is selected as the target peak PS.

[0196] The display section 20 of the remote controller 55 does not display a long advice message due to display space. Therefore, in the display section 20 of the remote controller 55, the number of the "diagnosis code" (here, 5-200) is displayed instead of the advice message. The number of the diagnosis code and the corresponding advice message are described in a document prepared corresponding to the remote controller 55 (such as an operation manual of the remote controller 55). The user can check the content of the advice message by comparing the displayed diagnosis code with the document.

[0197] Next, Fig.34 is a diagram showing a restricted mode 860 ( Fig.13 ) is a diagram showing the screen transition of the display unit 20 of the remote controller 55. Fig.33 When the menu key 32 is operated on the limited mode selection screen 810b (character string "Learning Only") of Fig.13 Here, as another example of the screen of the display unit 20, the candidate selection ( Fig.13 Another example of the screen in step 864 in FIG. 1 and when learning is completed ( Fig.13 Another example of the screen displayed during step 867 in FIG.

[0198] In the restricted mode 860, the screen display for candidate selection is similar to Fig.33 First, a candidate selection message is displayed on the display unit 20 in the form of a character string "Select the correct distance", and a plurality of peak candidates are displayed on the second candidate confirmation screen 822b, the third candidate confirmation screen 822c, etc., and these screens can be mutually transitioned on the next screen. When the menu key 32 is operated on any candidate confirmation screen, the displayed peak candidate is selected as the target peak PS.

[0199] Even when learning is completed, a long character string is not displayed on the display section 20 of the remote controller 55. Therefore, when learning in the limited mode 860 is completed, only “Completed” is displayed on the display section 20 of the remote controller 55.

Claims

1. A level meter for measuring the level of an object stored in a container, the level meter comprising: a transmitting / receiving unit, the transmitting / receiving unit comprising a transmitting circuit for transmitting a measuring signal for measuring the horizontal height and a receiving circuit for receiving a reflected signal generated due to reflection of the measuring signal; a distribution determining unit, the distribution determining unit determining a reception intensity distribution of the reflection signal with respect to a distance from the level meter based on the reception intensity of the reflection signal received by the receiving circuit; an extraction unit that extracts a peak position and a peak intensity from the reception intensity distribution determined by the distribution determination unit; a measurement value determination unit that determines a measurement value related to the distance to the object or the horizontal height based on the peak position extracted by the extraction unit; a candidate determination unit that extracts, through the extraction unit, a plurality of combinations of the peak positions and the peak intensities from the reception intensity distribution determined by the distribution determination unit, and determines the plurality of combinations as a plurality of peak candidates; as well as A display section configured to display information related to the measurement value and the reception intensity corresponding to each of the plurality of peak candidates determined by the candidate determination unit.

2. The level meter according to claim 1, wherein: When any one of the multiple peak candidates displayed on the display unit is selected as a target peak, the measurement value determination unit removes the peak candidates other than the target peak from the received intensity distribution, and determines the distance or the horizontal height of the object based on the target peak as the measurement value related to the object. 3 . The level meter according to claim 2 , wherein after the target peak is selected, the display section displays the measurement value corresponding to the target peak and the information related to the reception intensity as a peak candidate. 4 . The level meter according to claim 2 , wherein after the target peak value is selected, information on the target peak value can be erased. 5 . The level meter according to claim 1 , wherein when displaying the information on the measurement value and the reception intensity corresponding to each of the plurality of peak candidates, the display section displays stability of the reception intensity.

6. The level meter according to claim 1, wherein: After the target peak value is selected, diagnosis regarding the measurement environment is performed based on the target peak value and the reception intensity distribution, and the display section displays an advice message regarding the measurement environment of the level meter according to a result of the diagnosis.

7. The level meter according to claim 1, wherein: After selecting the target peak, diagnosis about the measurement environment is performed based on the target peak and the reception intensity distribution, and the measurement value determination unit performs optimization of settings required to determine a measurement value about the distance or level of the object according to a result of the diagnosis.

8. The level meter according to claim 7, wherein: The measurement value determination unit performs optimization of settings required for determining the measurement value related to the distance to the object or the level by applying predetermined settings corresponding to the classification of the result of the diagnosis.

9. The level meter according to claim 1, wherein questions regarding measurement conditions of the level meter are displayed on the display section, and optimization of settings required for determining the measured value of the distance to the object or the level is performed based on input of answers to the questions.

Images