JP4060008B2 - Moisture measuring device for ready-mixed concrete, mortar, sand, etc. and measuring method thereof - Google Patents

Description

BACKGROUND OF THE INVENTION
The present invention relates to a moisture measuring device and a moisture measuring method for measuring any one of ready-mixed concrete, mortar, and sand.
[Prior art]
Conventionally, various devices for measuring moisture such as ready-mixed concrete and mortar have been proposed as follows.
For example, there is one that obtains moisture from the weight change by heating and drying the object to be measured (using a lamp, a heater, or high-frequency heating), but in this case, the measurement takes too much time. In addition, there is a device that irradiates and transmits radiation (radioisotope) to an object to be measured, and obtains moisture by attenuation, but in this case, the apparatus is large and expensive. In addition, there are some that irradiate and transmit microwaves to the object to be measured and obtain moisture by attenuation, but in this case, other than sand can not be measured, if you try to measure raw concrete or mortar, the attenuation is large There is a problem that the necessary sensitivity cannot be obtained.
[Problems to be solved by the invention]
This invention is made | formed in view of the said situation, and provides the water | moisture content measuring apparatus and the water | moisture content measuring method which can measure water | moisture content, such as ready-mixed concrete and mortar, correctly and with sufficient workability | operativity.
[Means for Solving the Problems]
According to the moisture measuring apparatus according to the first aspect of the present invention, the apparatus measures the capacitance of any one of ready-mixed concrete, mortar, and sand, which are objects to be measured, provided in the apparatus main body. The moisture content can be determined based on the measurement of the capacitance of any one of ready-mixed concrete, mortar, and sand, which is the object to be measured, contained in the sample case attached to the main body, and the operation unit By providing the display unit, the display unit can facilitate the confirmation of the measurement results, and the sample case can be attached to and detached from the device body. It is easy to clean, or when it is broken, it is easy to clean the new part, and even if the connector part breaks down or breaks, it can be easily replaced. Since a capacity, there is an advantage that requires only replacement of the connection connector portion only.
Furthermore, according to the moisture measuring apparatus according to the first aspect of the present invention, since the sample case is a case having an inner surface as an inclined surface, the inner surface of the sample case is formed as an inclined surface, so that the object to be measured can be easily taken in and out. In addition, by providing a mounting guide that engages with a mounting guide groove provided on the bottom surface of the sample case on the upper case in the device, the sample case can be attached to the device body without worrying about the positional relationship with the connector. It can be securely mounted at a predetermined position.
The moisture measuring method for measuring any one of ready-mixed concrete, mortar, and sand according to claim 2 measures the capacitance of any one object to be measured in ready-mixed concrete, mortar, and sand. In the moisture measuring method for determining the moisture content of the object to be measured by the means to be provided, the electrode case is provided in the sample case for housing the object to be measured used in the apparatus, and the electrode part of the sample case is provided in the apparatus main body. Provided with a moisture measuring device in which the connector portion is detachable from the apparatus main body, and the inner surface of the storage area of the sample case is inclined such that the opening surface side is larger and the bottom portion is smaller. A moisture measuring method characterized by comprising a mounting guide that is formed into a surface shape and that is provided on an upper case of the apparatus to engage with a mounting guide groove provided on the bottom surface of the sample case. Moreover, the LCR series resonant circuit having a variable capacitor, and supplying high-frequency power having a predetermined frequency from the outside, a step of taking a resonance capacitance of the variable capacitor variable to raw across the variable capacitor after the resonance state Connecting any one of the objects to be measured from concrete, mortar, and sand, changing the capacity of the variable capacitor to resonate, and from the capacitance change value of the variable capacitor at each resonance, And a step of obtaining a capacitance.
According to the present invention, the capacitance of the object to be measured can be accurately obtained from the capacitance change value of the variable capacitor by utilizing the resonance with the simplest circuit configuration among the LCR series resonance circuits.
The moisture measuring method for measuring any one of ready-mixed concrete, mortar, and sand according to the invention of claim 3 measures the capacitance of any one object to be measured among ready-mixed concrete, mortar, and sand. In the moisture measuring method for determining the moisture content of the object to be measured by the means to be provided, the electrode case is provided in the sample case for housing the object to be measured used in the apparatus, and the electrode part of the sample case is provided in the apparatus main body. Provided with a moisture measuring device in which the connector portion is detachable from the apparatus main body, and the inner surface of the storage area of the sample case is inclined such that the opening surface side is larger and the bottom portion is smaller. A moisture measuring method characterized by comprising a mounting guide that is formed into a surface shape and that is provided on an upper case of the apparatus to engage with a mounting guide groove provided on the bottom surface of the sample case. Moreover, the high frequency bridge circuit constituted by CR equipped with two variable capacitors, a high frequency power of a predetermined frequency applied from the outside, to balance the high frequency bridge circuit by varying the capacitance of the two variable capacitors step Connecting any one of ready-mixed concrete, mortar, and sand to both ends of one of the variable capacitors, and changing the capacity of the two variable capacitors to balance the high-frequency bridge circuit; And obtaining a capacitance of the device under test from a capacitance change value of one of the variable capacitors connected to the device under test.
According to the present invention, the L (inductance) component is unnecessary, the circuit configuration is simplified compared to the LCR series resonance circuit, and the balance of the high-frequency bridge circuit that is the simplest among the high-frequency bridge circuits is utilized. The capacitance of the object to be measured can be accurately obtained from the capacitance change value of the one variable capacitor.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
This moisture measuring device for ready-mixed concrete, mortar, sand and the like estimates the moisture content by measuring the capacitance of ready-made concrete, mortar, sand and the like.
In addition, since the capacitance is affected by the bulk density, it is possible to estimate the moisture content with higher accuracy by measuring the mass of the sample and correcting the capacitance.
In general, the water content W and the capacitance C can be expressed by the equation W = K · C. Here, K is a constant depending on the material.
Moreover, it is thought that the change in the capacitance measured by the moisture measuring device mainly depends on the moisture content W of the ready-mixed concrete or the like to be measured existing between the measurement electrodes.
Therefore, the water content W can be obtained by measuring the capacitance C of the object to be measured.
The moisture measuring device of the present invention is based on the above principle, and the moisture measuring device of the embodiment of the present invention will be described in detail below.
1 and 2 attached herewith show the configuration of the moisture measuring apparatus according to the embodiment of the present invention, which includes a box-shaped lower case 13, a packing 19 and an upper case 14 that constitute the apparatus main body. is doing.
Between the lower case 13 and the upper case 14, a battery storage unit 50, a support substrate 21 and a display unit 60 comprising an LCD (liquid crystal), a control program for this moisture measuring device, are stored, and a capacitance calculation, etc. The CPU board assembly 2 including the CPU 80 for performing various calculations of the above, display control of the display unit 60, and the like, and the operation switch board assembly 3 constituting the operation unit 70 are incorporated.
Furthermore, an LCR series resonance circuit or a high-frequency bridge circuit described later is mounted in the apparatus main body.
The operation unit 70 is configured such that the panel sheet 4 and the filter 17 are stacked on the operation switch board assembly 3 so that a large number of operation keys 3a for inputting numerical values and items can be operated on the upper case 14. .
Further, the display screen 60a of the display unit 60 for displaying various measurement results and the like is configured to be exposed on the upper case 14 from the hole 4a and the transparent part 17a provided in the panel sheet 4 and the filter 17, respectively. Visible from above the case 14.
By providing the operation unit 70 and the display unit 60 as described above, the operation is facilitated and the confirmation of display contents is facilitated.
An accommodation region 90 for the sample case 40 is formed on the upper case 14, and the contact assembly 1 that makes electrical connection with the sample case 40 can be attached to and detached from a vertical wall portion 14 a that forms the accommodation region 90. It is attached to. Since the contact assembly 1 is detachable, there is an advantage that maintenance and replacement of the contact assembly 1 are easy.
The inner surface of the accommodation region 90 of the sample case 40 is formed in an inclined surface shape having a large opening surface side and becoming smaller toward the bottom, thereby facilitating entry / exit of an object to be measured such as ready-mixed concrete 100.
Further, on the upper case 14, a mounting guide 40b having a wide width on the side of the vertical wall 14a and a narrow width on the insertion end side is provided, which is engaged with a mounting guide groove 40a provided on the bottom surface of the sample case 40, as shown in FIG. Thus, by mounting the sample case 40 in the direction of the arrow shown in FIG. 1 while engaging the mounting guide 40b in the mounting guide groove 40a of the sample case 40, without worrying about the positional relationship with the contact assembly 1, The sample case 40 can be accurately positioned on the upper case 14 with the contact assembly 1 to be in a measurement state.
The mounting guide groove 40a and the mounting guide 40b may be provided not only in the sample case and the main body device but also in either the sample case or the main body device.
The display unit 60 is fixed in place using the upper fixture 7, the lower fixture 8 and the screw 200.
The battery storage unit 50 includes a lower battery holder 16a and an upper battery holder 16b at the lower part of the lower case 13, and stores, for example, a single-type dry battery between the first and second battery contacts 10 and 11. It is like that.
A battery lid packing 20, a second battery contact 10, a battery lid 15, and a battery lid set screw 9 are arranged on the side wall of the lower case 13.
A communication connector 22 is arranged on the back side of the lower case 13 so that data can be output to a printer or a computer. The AC jack 12 is arranged so that it can be used with two power sources. Yes. A communication connector cover 23 and an AC jack cover 18 are attached to the communication connector 22 and the AC jack 12, respectively, and have a waterproof structure.
FIG. 4 attached herewith shows the contact assembly 1 that is electrically connected to the measurement electrodes 41 and 42 provided on the sample case 40.
As shown in FIG. 4, the contact assembly 1 has a pair of contact springs 32, a contact cover 34, and a contact fixture 35 with a screw 200 or the like with respect to a pair of connector receivers 36 provided on the plate 33. It is assembled using. The analog substrate 31 is attached to the back surface of the plate 33.
As shown in FIG. 1, the measurement electrodes 41 and 42 provided on the sample case 40 are connected to the pair of contact springs 32, respectively, so that the measurement exposed to the sample storage portion 45 provided inside the sample case 40. By storing, for example, ready-mixed concrete 100 between the exposed surfaces 41a and 42a of the electrodes 41 and 42, the moisture content of the ready-mixed concrete 100 can be measured by the moisture measuring device of the present embodiment, and the capacitance can be calculated. It is said.
In the present invention, it is not essential to provide the sample case 40. Instead of the sample case 40, the electrode inserted in the object to be measured is connected to the moisture measurement of the present embodiment with a cable or the like. It is also possible to measure the capacitance by connecting to the apparatus and measuring it.
FIG. 5 and FIG. 6 attached show configurations of an LCR series resonance circuit and a high-frequency bridge circuit that measure the capacitance mounted on the moisture measuring device according to the present embodiment.
The LCR series resonance circuit shown in FIG. 5 supplies high-frequency power having a frequency f from a high-frequency power source 150 to a series resonance circuit including resistors R, r, a coil (inductor) L, and a variable capacitor C, and the capacitance of the variable capacitor C is increased. A sample case 40 accommodating the ready-mixed concrete 100 is attached to the apparatus main body, and the resistance Rx equivalently shows the electrical characteristics of the ready-mixed concrete 100 at both ends of the variable capacitor C brought into the resonance state. Then, the parallel circuit of the capacitor Cx is connected, the capacitance of the variable capacitor C is varied again, resonance is performed, and the capacitance of the ready-mixed concrete 100 is measured from the capacitance change value of the variable capacitor C at each resonance.
In FIG. 5, V is a voltmeter.
As a result, the capacitance of the device under test can be accurately obtained from the capacitance change value of the variable capacitor VC using the resonance with the simplest circuit configuration among the LCR series resonance circuits.
The high-frequency bridge circuit shown in FIG. 6 is supplied from a high-frequency power source 150 to a high-frequency bridge circuit including a high-frequency power having a frequency f and a detector DET, and connecting resistors R1, R2, R3, variable capacitors VC1, VC2, and capacitor C3 in a bridge connection. The capacitance of the two variable capacitors VC1 and VC2 is varied to balance the high-frequency bridge circuit. Next, the sample case 40 containing the ready-mixed concrete 100 is mounted on the main body of the apparatus, and is attached to both ends of the variable capacitor V2. The parallel circuit of the resistor Rx and the capacitor Cx expressed equivalently is connected, and the capacitances of the two variable capacitors VC1 and VC2 are changed again to balance the high-frequency bridge circuit.
And the electrostatic capacitance of the ready-mixed concrete 100 which is the said to-be-measured object is calculated | required from the capacity | capacitance change value of one variable capacitor VC2.
As a result, the L (inductance) component is unnecessary, the circuit configuration is more simplified than that of the LCR series resonance circuit, and the balance of the high-frequency bridge circuit that is the simplest among the high-frequency bridge circuits is utilized. From the capacitance change value of the variable capacitor VC2, it is possible to accurately obtain the capacitance of the ready-mixed concrete that is the object to be measured.
It should be noted that a conductor that affects the measured value of metal or the like is not disposed in the vicinity of the installation location of the sample case 40 in the apparatus main body, so that the mounting position of the metal part or the like is not required when the moisture measuring apparatus is assembled. Even if there is a slight deviation, there is no instrumental error, and the characteristics of the object to be measured can be more accurately reflected in the measurement value, and the accuracy of the measurement result can be expected.
【The invention's effect】
According to the present invention described above in detail, the following effects can be obtained.
According to the first aspect of the present invention, it is possible to realize a moisture measuring device that can ensure the accuracy of measurement of an object to be measured such as ready-mixed concrete, mortar, sand, etc., and further facilitate the operation and confirm the measurement result. The sample case can be easily cleaned and replaced with a new one. In addition, the connector can be easily cleaned even if the connector is broken or broken. Part replacement is easy, and the inner surface of the sample case is inclined, making it easy to put in and out of the object to be measured. It is possible to provide a moisture measuring device that can be securely attached to a position .
According to the second aspect of the present invention, it is possible to provide a moisture measuring method capable of accurately obtaining the capacitance of the object to be measured with a simple configuration using an LCR series resonance circuit.
According to the invention described in claim 3, it is possible to provide a moisture measuring method capable of accurately obtaining the capacitance of the object to be measured from the capacitance change value of the variable capacitor with a simple configuration using a high frequency bridge circuit. can Ru.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a moisture measuring device according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a moisture measuring device according to the present embodiment.
FIG. 3 is a perspective view of a bottom portion of a storage case in the moisture measuring device according to the present embodiment.
FIG. 4 is an exploded perspective view of a connector portion of the moisture measuring device according to the present embodiment.
FIG. 5 is a circuit diagram showing an LCR resonance circuit mounted on the moisture measuring device of the present embodiment.
FIG. 6 is a circuit diagram showing a high-frequency bridge circuit mounted on the moisture measuring device of the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Contact assembly 2 CPU board assembly 3 Operation switch board assembly 3a Operation key 4 Panel sheet 13 Lower case 14 Upper case 15 Battery cover 22 LCD module 40 Sample case 41 Measurement electrode 42 Measurement electrode 50 Battery storage part 60 Display part 70 Operation part 90 Storage area 100 Ready-mixed concrete 150 High-frequency power supply Rx Resistance Cx Capacitor VC1 Variable capacitor VC2 Variable capacitor C Variable capacitor DET Detector L Coil

Claims (3)

Capacitance of any one object to be measured out of ready-mixed concrete, mortar, and sand installed in the main body of the device, which has a display unit that displays operation procedures and measurement results, and an operation unit that inputs numerical values and selects items Moisture measuring device for determining the moisture content of any one of the measured objects of ready-mixed concrete, mortar, and sand contained in a sample case that is detachably attached to the apparatus main body Because
A configuration in which high frequency power of a predetermined frequency is supplied from the outside to an LCR series resonance circuit having a variable capacitor in the device, and the capacitance of the variable capacitor is varied to resonate, or in the device A high-frequency bridge circuit composed of CR with two variable capacitors is externally supplied with a high-frequency power supply of a predetermined frequency, and the capacitance of the two variable capacitors is varied to balance the high-frequency bridge circuit. It is characterized by comprising, and
The inner surface of the storage area of the sample case for storing the object to be measured is formed in an inclined surface shape that the opening surface side is large and decreases toward the bottom, the electrode case is provided on the sample case, and the sample is provided on the apparatus body. A connector portion is provided for electrical conduction with the electrode portion of the case . The connector portion is detachable from the apparatus main body, and engages with a mounting guide groove provided on the bottom surface of the sample case on the upper case of the apparatus. A moisture measuring device for measuring any one of ready-mixed concrete, mortar, and sand, characterized by being provided with a mounting guide . The means for measuring the capacitance of the fresh concrete, mortar, any one of the object of the sand, moisture measuring method for determining the moisture content of the object to be measured, housing the object to be measured for use in the apparatus The sample case is provided with an electrode portion, and the apparatus main body is provided with a connector portion for electrical connection with the electrode portion of the sample case, and the connector portion is provided with a moisture measuring device that is detachable from the apparatus main body. In addition, the inner surface of the storage area of the sample case is formed in an inclined surface shape that the opening surface side is large and decreases toward the bottom, and is mounted on the upper case of the apparatus to engage with a mounting guide groove provided on the bottom surface of the sample case A moisture measuring method characterized in that a guide is provided ,
A step of supplying resonance to the LCR series resonance circuit having a variable capacitor by supplying high frequency power of a predetermined frequency from the outside and changing the capacitance of the variable capacitor;
A process of connecting any one of ready-mixed concrete, mortar and sand to both ends of the variable capacitor after the resonance state, and changing the capacitance of the variable capacitor to resonate;
A moisture measuring method for measuring any one of ready-mixed concrete, mortar, and sand, comprising a step of obtaining a capacitance of the object to be measured from a capacitance change value of the variable capacitor at each resonance. The means for measuring the capacitance of the fresh concrete, mortar, any one of the object of the sand, moisture measuring method for determining the moisture content of the object to be measured, housing the object to be measured for use in the apparatus The sample case is provided with an electrode portion, and the apparatus main body is provided with a connector portion for electrical connection with the electrode portion of the sample case, and the connector portion is provided with a moisture measuring device that is detachable from the apparatus main body. In addition, the inner surface of the storage area of the sample case is formed in an inclined surface shape that the opening surface side is large and decreases toward the bottom, and is mounted on the upper case of the apparatus to engage with a mounting guide groove provided on the bottom surface of the sample case A moisture measuring method characterized in that a guide is provided ,
A step of balancing the high-frequency bridge circuit by adding a high-frequency power source of a predetermined frequency from the outside to a high-frequency bridge circuit composed of CR having two variable capacitors, and changing the capacitance of the two variable capacitors;
Connecting one arbitrary measured object of ready-mixed concrete, mortar, and sand to both ends of one variable capacitor, changing the capacitance of the two variable capacitors, and balancing the high-frequency bridge circuit;
Measuring the any one of the fresh concrete, mortar, sand, characterized in that a step of determining the capacitance of the object to be measured from the change in capacitance value of one variable capacitor connected to the object to be measured Moisture measurement method.

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