Specific Gravity Measurement Device

Abstract

A specific gravity measurement device has an in-air weight sensor that measures the weight, in air, of an object to be measured, memory that automatically stores the weight in air, an in-liquid weight sensor that measures the weight, in a liquid, of the object to be measured, a memory that automatically stores the weight in the liquid, a measuring device that, on the basis of the weight in air and the weight in a liquid, measures the specific gravity of the object, and an initialization device that automatically initializes the display of the specific gravity of the object, after the object to be measured is retrieved from within the liquid.

Claims

1. A specific gravity measurement device, comprising: a display means for displaying a predetermined content; an in-air weight measurement means for measuring an in-air weight of an object to be measured in air; an in-air weight storage means for automatically storing the in-air weight measured by the in-air weight measurement means; an in-liquid weight measurement means for measuring an in-liquid weight of the object to be measured in a liquid; an in-liquid weight storage means for automatically storing the in-liquid weight measured by the in-liquid weight measurement means; a measuring means for measuring a specific gravity of the object to be measured based on the in-air weight stored in the in-air weight storage means and the in-liquid weight stored in the in-liquid weight storage means; and an initialization means for automatically initializing a display of the specific gravity of the object to be measured by the measuring means and displayed on the display means after the object to be measured is taken out of the liquid.

2. A specific gravity measurement device, comprising: a display means for displaying a predetermined content; an in-liquid weight measurement means for measuring an in-liquid weight of an object to be measured in a liquid; an in-liquid weight storage means for automatically storing the in-liquid weight in the liquid measured by the in-liquid weight measurement means; a measuring means for measuring a specific gravity of the object to be measured based on an in-air weight of the object to be measured in air and the in-liquid weight in the liquid stored in the in-liquid weight storage means; and an initialization means for automatically initializing a display of the specific gravity of the object to be measured by the measuring means and displayed on the display means after the object to be measured is taken out of the liquid.

3. The specific gravity measurement device according to claim 1, wherein the in-air weight storage means automatically stores the in-air weight when a difference in the in-air weight of the object to be measured in air measured by the in-air weight measurement means falls within a first predetermined range set in advance, or automatically stores the in-air weight after a first predetermined time has passed since the difference fell within the first predetermined range.

4. The specific gravity measurement device according to claim 1, wherein the in-liquid weight storage means automatically stores the in-liquid weight when a difference in the in-liquid weight of the object to be measured in the liquid measured by the in-liquid weight measurement means falls within a second predetermined range set in advance, or automatically stores the in-liquid weight after a second predetermined time has passed since the difference fell within the second predetermined range.

5. The specific gravity measurement device according to claim 2, wherein the in-liquid weight storage means automatically stores the in-liquid weight when a difference in the in-liquid weight of the object to be measured in the liquid measured by the in-liquid weight measurement means falls within a second predetermined range set in advance, or automatically stores the in-liquid weight after a second predetermined time has passed since the difference fell within the second predetermined range.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is an external perspective view of a specific gravity measurement device according to an embodiment of the present invention, viewed from the front side.

[0028] FIG. 2(a) is a vertical side cross-sectional view of the specific gravity measurement device according to the same embodiment and FIG. 2(b) is a block diagram of a measuring unit of the specific gravity measurement device according to the same embodiment.

[0029] FIG. 3 is a flowchart for explaining a process when measuring specific gravity of an object to be measured using the specific gravity measurement device according to the same embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, a preferred embodiment of a specific gravity measurement device according to the present invention will be described in detail with reference to the drawings. It is noted that, in the following description, when vertical and horizontal directions are indicated, it shall mean vertical and horizontal directions when viewed from the front of the figure.

[0031] Referring to FIGS. 1-3, specific gravity measurement device 1 is composed of a rectangular cylindrical liquid tank 2 containing a liquid L, an object-to-be-measured receiving member 4 which is accommodated in the liquid tank 2 via a support unit 3 in a non-contact manner and into and out of which the liquid L in the liquid tank 2 can flow freely, a mid-air mounting member 5 on which an object to be measured M is placed when a weight of the object to be measured M in air is measured, and a measuring device 6 receiving and supporting the object-to-be-measured receiving member 4 via the support unit 3. The measuring device 6 includes an electromagnetic sensor 7 for converting a weight acting on the object-to-be-measured receiving member 4 into an electric signal and a measuring unit 8 (see FIG. 2(b)) for measuring specific gravity of the object to be measured M from an output of the sensor 7 when the object to be measured M is placed on the mid-air mounting member 5 and an output of the sensor 7 when the object to be measured M is submerged and placed on the object-to-be-measured receiving member 4. As shown in FIG. 2(b), the measuring unit 8 is composed of an amplifier 8a for amplifying the output of the sensor 7 and outputting an analog signal corresponding to the load, an A-D converter 8b for converting the analog signal into a digital signal, a CPU 8c, a ROM 8d storing a program, etc., a RAM 8e serving as a work area, a buffer memory, etc., an input key 8f capable of inputting various data, and a display unit 8g capable of displaying various contents.

[0032] Thus, a feature of the specific gravity measurement device 1 thus configured is a part related to processing contents when measuring the specific gravity of the object to be measured M. Thus, this point will be described specifically with reference to FIG. 3.

[0033] Referring to FIG. 3, first, a user makes initial settings (step S1). More specifically, the user presses the input key 8f (see FIG. 1) while the liquid L is in the liquid tank 2 as shown in FIG. 2(a) and the object to be measured M is neither placed on the mid-air mounting member 5 nor put into the liquid tank 2. As a result, the CPU 8c (see FIG. 2(b)) resets the output of the sensor 7, that is, the weights of the object-to-be-measured receiving member 4, the mid-air mounting member 5, and the support unit 3, and stores 0 in the RAM 8e and also causes the display unit 8g to display 0.

[0034] The user further presses the input key 8f (see FIG. 1) to set a time to pass (for example, 0 seconds, 5 seconds, 10 seconds, 15 seconds, 20 seconds, 30 seconds, etc.) before the weight of the object to be measured M in air measured by the sensor 7 is stored in the RAM 8e. This setting content is stored in the ROM 8d by the CPU 8c. The user further presses the input key 8f (see FIG. 1) to set a time to pass (for example, 0 seconds, 5 seconds, 10 seconds, 15 seconds, 20 seconds, 30 seconds, etc.) before the weight of the object to be measured M in the liquid measured by the sensor 7 is stored in the RAM 8e. This setting content is stored in the ROM 8d by the CPU 8c.

[0035] Thus, after such initial settings are made (step S1), the CPU 8c reads out a program stored in the ROM 8d and checks whether or not the output of the sensor 7 is outside a predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) set in advance. More specifically, the CPU 8c checks the output of the sensor 7 at fixed intervals, obtains a difference between the previously checked output value from the sensor 7 and the currently checked output value from the sensor 7, and checks whether or not the value of the difference is outside a predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) set in advance when the program was created (step S2). When not outside the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S2: NO), the CPU 8c determines that the object to be measured M is not placed on the mid-air mounting member 5, and repeats the processing of step S2 until the value becomes outside the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.). On the other hand, when the value is outside the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S2: YES), the CPU 8c determines that the object to be measured M has been placed on the mid-air mounting member 5 by a person or robot, and moves onto the processing of step S3.

[0036] Next, the CPU 8c checks the output of the sensor 7 at fixed intervals, obtains a difference between the previously checked output value from the sensor 7 and the currently checked output value from the sensor 7, and checks whether or not the value of the difference is within a predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) set in advance when the program was created (step S3). When not within the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S3: NO), the CPU 8c determines that the output from the sensor 7 is not stable, and repeats the processing of step S3 until the value falls within the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.). On the other hand, when the value is within the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S3: YES), the CPU 8c determines that the currently checked output value from the sensor 7 is the weight of the object to be measured M in air. As a result, the weight of the object to be measured M in air is measured (step S4). At this time, the CPU 8c causes the display unit 8g to display the weight of the object to be measured M in air and also causes the display unit 8g to display an indication informing that the weight of the object to be measured M in air has been determined.

[0037] Next, the CPU 8c reads out, from the ROM 8d, the setting set in step S1 above as to the time to pass before the weight of the object to be measured M in air is stored in the RAM 8e, and stores the measured weight of the object to be measured M in air in the RAM 8e after the set time has passed (step S5). More specifically, for example, when the set time is 0 seconds, the CPU 8c stores the measured weight of the object to be measured M in air in the RAM 8e immediately after the weight of the object to be measured M in air is measured. When the set time is 5 seconds, the CPU 8c stores the measured weight of the object to be measured M in air in the RAM 8e after 5 seconds have passed since the weight of the object to be measured M in air was measured.

[0038] Thus, in this manner, the weight of the object to be measured M in air with high measurement accuracy can be automatically stored in the RAM 8e by taking the output value from the sensor 7 falling within the predetermined range as the weight of the object to be measured M in air and storing the weight in the RAM 8e immediately or after the predetermined time has passed.

[0039] Next, the CPU 8c checks the output of the sensor 7 at fixed intervals, obtains a difference between the previously checked output value from the sensor 7 and the currently checked output value from the sensor 7, and checks whether or not the value of the difference is outside a predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) set in advance when the program was created (step S6). When not outside the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S6: NO), the CPU 8c determines that the object to be measured M is not submerged in the object-to-be-measured receiving member 4, and repeats the processing of step S6 until the value becomes outside the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.). On the other hand, when the value is outside the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S6: YES), the CPU 8c determines that the object to be measured M has been submerged in the object-to-be-measured receiving member 4 by a person or robot, and moves onto the processing of step S7.

[0040] Next, the CPU 8c checks the output of the sensor 7 at fixed intervals, obtains a difference between the previously checked output value from the sensor 7 and the currently checked output value from the sensor 7, and checks whether or not the value of the difference is within a predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) set in advance (step S7). When not within the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S7: NO), the CPU 8c determines that the output from the sensor 7 is not stable, and repeats the processing of step S7 until the value falls within the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.). On the other hand, when the value is within the predetermined range (for example, ?0.0001 g to 0.0001 g, 0 to 0.01 g, etc.) (step S7: YES), the CPU 8c determines that the currently checked output value from the sensor 7 is the weight of the object to be measured M in the liquid. As a result, the weight of the object to be measured M in the liquid is measured (step S8). At this time, the CPU 8c causes the display unit 8g to display the weight of the object to be measured M in the liquid and also causes the display unit 8g to display an indication informing that the weight of the object to be measured M in the liquid has been determined.

[0041] Next, the CPU 8c reads out, from the ROM 8d, the setting set in step S1 above as to the time to pass before the weight of the object to be measured M in the liquid is stored in the RAM 8e, and stores the measured weight of the object to be measured M in the liquid in the RAM 8e after the set time has passed (step S9). More specifically, for example, when the set time is 0 seconds, the CPU 8c stores the measured weight of the object to be measured M in the liquid in the RAM 8e immediately after the weight of the object to be measured M in the liquid is measured. When the set time is 5 seconds, the CPU 8c stores the measured weight of the object to be measured M in the liquid in the RAM 8e after 5 seconds have passed since the weight of the object to be measured M in the liquid was measured.

[0042] Thus, in this manner, the weight of the object to be measured M in the liquid with high measurement accuracy can be automatically stored in the RAM 8e by taking the output value from the sensor 7 falling within the predetermined range as the weight of the object to be measured M in the liquid and storing the weight in the RAM 8e immediately or after the predetermined time has passed.

[0043] Next, the CPU 8c reads out the weight of the object to be measured M in air and the weight of the object to be measured M in the liquid automatically stored in the RAM 8e, and measures specific gravity of the object to be measured M. More specifically, the CPU 8c measures specific gravity of the object to be measured M by calculating using the numerical expression of the weight of the object to be measured M in air/(the weight of the object to be measured M in air?the weight of the object to be measured M in the liquid) (step S10).

[0044] Next, the CPU 8c causes the display unit 8g to display the measured specific gravity of the object to be measured M (step S11).

[0045] Next, the CPU 8c checks the output of the sensor 7 at fixed intervals and checks whether or not the output value from the sensor 7 is within a predetermined range (for example, a range of 0 to 0.0001 g) set in advance when the program was created (step S12). When not within the predetermined range (for example, the range of 0 to 0.0001 g) (step S12: NO), the CPU 8c determines that a person or robot has not taken out the object to be measured M from the object-to-be-measured receiving member 4, and repeats the processing of step S12 until the output value falls within the predetermined range (for example, the range of 0 to 0.0001 g). On the other hand, when within the predetermined range (for example, the range of 0 to 0.0001 g) (step S12: YES), the CPU 8c determines that a person or robot has taken out the object to be measured M from the object-to-be-measured receiving member 4, and initializes the specific gravity of the object to be measured M displayed on the display unit 8g (causes the display unit 8g to display 0) (step S13). At this time, the CPU 8c also clears the weight of the object to be measured M in air and the weight of the object to be measured M in the liquid automatically stored in the RAM 8e.

[0046] In this manner, the specific gravity of the object to be measured M displayed on the display unit 8g is initialized (0 is displayed) when the output value of the sensor 7 falls within the predetermined range (for example, the range of 0 to 0.0001 g). By doing so, the occurrence of troubles such as a situation where the display disappears although the specific gravity of the object to be measured M is not checked can be reduced.

[0047] Thus, the CPU 8c completes the specific gravity measurement processing of the object to be measured M after completing the processing of step S13 above. If specific gravity of another object to be measured M is to be measured successively with the initial settings (see step S1) kept as they are, the processing of step S2 to step S13 only needs to be performed.

[0048] Thus, according to the present embodiment described above, the measured weight of the object to be measured M in air is automatically stored in the RAM 8e, the measured weight of the object to be measured M in the liquid is automatically stored in the RAM 8e, the specific gravity of the object to be measured M is measured using the weight of the object to be measured M in air and the weight of the object to be measured M in the liquid stored in the RAM 8e, and the measured specific gravity is displayed on the display unit 8g. When the object to be measured M is taken out of the liquid, the display of the specific gravity displayed on the display unit 8g is automatically initialized. This makes it possible to automate the specific gravity measurement work, thereby eliminating the need to press the input key 8f as in the conventional case, so that measurement errors due to artificial vibration can be reduced substantially close to zero. As a result, according to the present embodiment, measurement errors can be significantly reduced, and thus, a true specific gravity value can be repeatedly measured. Further, according to the present embodiment, the work using a robot is also possible.

[0049] The specific gravity measurement device shown in the present embodiment is merely an example and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. For example, the structure of the specific gravity measurement device is not limited to the structure shown in the present embodiment, and the present invention can be applied to a specific gravity measurement device of any structure. For example, the present invention can be applied to such a specific gravity measurement device that a weight of an object to be measured M in air is known in advance without measurement, a weight of the object to be measured M in a liquid is measured, and specific gravity of the object to be measured M is measured using the previously known weight of the object to be measured M in air and the measured weight of the object to be measured M in the liquid. At this time, the processing of step S2 to step S6 shown in FIG. 3 becomes unnecessary, and the user inputs the previously known weight of the object to be measured M in air using the input key 8f in step S1.

[0050] Further, in the present embodiment, the same predetermined range is given as an example in measuring the weight of the object to be measured M in air and the weight of the object to be measured M in the liquid. However, the present invention is not limited thereto, and the predetermined range may be set to different ranges in measuring the weight of the object to be measured M in air and the weight of the object to be measured M in the liquid, respectively.

[0051] Further, in the present embodiment, the example in which the predetermined range is set in advance when the program is created has been shown. However, the present invention is not limited thereto, and the user may optionally set the predetermined range. At this time, the user sets it using the input key 8f in the processing of step S1. It is a matter of course that the user may optionally set all the predetermined ranges in step S3, step S7, and step S12 shown in FIG. 3 or may optionally set any of the predetermined ranges.

[0052] On the other hand, the determinations that the object to be measured M has been placed on the mid-air mounting member 5 and that the object to be measured M has been submerged in the object-to-be-measured receiving member 4 by the CPU 8c shown in the present embodiment are merely examples, and any method of determination is acceptable and the present invention is not limited thereto.