Moisture meter

Abstract

Provided is a moisture meter that can measure the moisture content of an object with high accuracy even when the user holds the moisture meter by hand. 【Solution means】 A moisture meter 1 that calculates the moisture content of an object by measuring the capacitance between a + electrode 31 and a - electrode 32, comprising a ground electrode 33 electrically connected to the - electrode, the ground electrode being brought into contact with the user's skin when measuring the capacitance of the object. The moisture meter further includes a housing 2, the + electrode, the - electrode, and the ground electrode are provided on the surface of the housing, each of the + electrode and the - electrode is provided on a first surface that is one surface of the housing, and the ground electrode is provided on a surface of the housing other than the first surface.

Description

Technical Field

[0001] The present invention relates to a moisture meter.

Background Art

[0002] As the background art in this technical field, there is a published utility model Japanese Utility Model Publication No. 62-99854 (Patent Document 1). This publication describes a "high-frequency wood moisture meter that measures the moisture content of wood and the like using high frequencies."

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a user measures the moisture content of an object while holding the moisture meter by hand, there is a risk of an error in the measurement result due to the influence of the hand.

Means for Solving the Problems

[0005] To solve the above problems, for example, the configuration described in the claims is adopted. This application includes a plurality of means for solving the above problems. For example, a moisture meter that measures the capacitance between a + electrode and a - electrode and calculates the moisture content of an object, comprising a ground electrode electrically connected to the - electrode, wherein the ground electrode is brought into contact with the user's skin when measuring the capacitance of the object, moisture meter.

Effects of the Invention

[0006] According to the present invention, it is possible to provide a moisture meter that can measure the moisture content of an object with high accuracy even when the user holds the moisture meter by hand. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0008] An example (embodiment) of the moisture meter will be described with reference to FIGS. 1 to 5. The moisture meter 1 in the present embodiment is a high-frequency moisture meter that measures the capacitance between the + electrode and the - electrode and calculates the moisture content of the object. The high-frequency moisture meter measures the capacitance that changes according to the increase or decrease of moisture by measuring the amount of high-frequency current flowing through it, and calculates the moisture content.

[0009] The moisture meter 1 includes a housing 2, a + electrode 31, a - electrode 32, a ground electrode 33, a display unit 4, and an operation unit 5. The housing 2 has a substantially rectangular parallelepiped shape. The housing 2 is made of an insulating member.

[0010] The + electrode 31, the - electrode 32, and the ground electrode 33 described later are provided protruding from the surface of the housing 2. The + electrode 31 and the - electrode 32 are provided on the first surface (the back surface shown in FIG. 2 in the present embodiment), which is one of the surfaces of the housing 2.

[0011] By the way, in a hand-held moisture meter that measures the moisture content of an object while the user holds the moisture meter by hand, there is a possibility that an error may occur in the measured value of the capacitance due to a human body (the user's hand) having a high moisture content approaching the moisture meter.

[0012] Regarding this point, conventionally, after holding the moisture meter by hand, the power of the moisture meter is turned on, and the capacitance is measured based on that state including the handle, so as to measure the change in capacitance caused only by the increase in moisture of the object.

[0013] However, after the power is turned on, since the user is a living human being, the hand holding the moisture meter may not be fixed at a certain position and may shift, which may cause an error in the measured value.

[0014] Therefore, the moisture meter 1 in the present embodiment includes a ground electrode 33. The ground electrode 33 is electrically connected to the - electrode 32 and is brought into contact with the user's skin when measuring the capacitance of the object. With this configuration, after the user's finger touches the ground electrode 33, by turning on the power of the moisture meter 1, the capacitance can be measured based on the state where the handle is at the same potential as the - electrode, so that it is possible to suppress an error in the measured value due to the influence of the handle.

[0015] The ground electrode 33 is provided on the second surface (the right side surface shown in FIG. 3 in the present embodiment) adjacent to the first surface, which is a surface of the housing 2 other than the first surface. With this configuration, the user's finger can be brought into contact with the ground electrode 33 while the + electrode 31 and the - electrode 32 are in contact with the object.

[0016] The + electrode 31, the - electrode 32, and the ground electrode 33 are each elongated and extend along the same direction. With this configuration, a wide - range electric field can be generated between the + electrode 31 and the - electrode 32, and between the + electrode 31 and the ground electrode 33, so that the measurement accuracy can be improved. Also, as in this embodiment, the electrode close to the ground electrode 33 may be the + electrode 31. That is, the + electrode 31 may be located between the - electrode 32 and the ground electrode 33.

[0017] The principle of the moisture meter 1 will be described. The moisture meter 1 increases or decreases the oscillation frequency according to the change in the capacitance of the object in contact with the high - frequency (20 - 22 MHz) oscillation circuit through each electrode. This signal is divided by a frequency divider through an amplifier circuit, and the microcomputer counts the period. First, in order to measure the capacitance of the air in the atmosphere during measurement, the + electrode 31 and the - electrode 32 are exposed to the air, and the power is turned on with the skin touching the ground electrode 33. Then, the divided period is counted and the value is stored in the storage unit inside the microcomputer. Next, the + electrode 31 and the - electrode 32 are brought into contact with the object, and similarly counted and stored. The difference between the two is calculated by the microcomputer, and the moisture content is calculated from this value and displayed on the display unit 4.

[0018] Note that the moisture content of the object may be calculated using the information on the density and thickness of the object input in advance by the operation unit 5. Also, since measurement values immediately after the + electrode 31 and the - electrode 32 are brought into contact with the object are likely to have errors, they may not be used.

[0019] A method of measuring the moisture content of an object using the moisture meter 1 will be described. First, the user's skin is brought into contact with the ground electrode 33 (contact step). Next, in parallel with the contact step, the power is turned on by the operation unit 5 of the moisture meter 1 with the + electrode 31 and the - electrode 32 exposed to the air (operation step). Next, as shown in FIG. 5, in parallel with the contact step, the + electrode 31 and the - electrode 32 are brought into contact with the object (measurement step).

[0020] Using the moisture meter 1 of the present embodiment described above, the following measurements 1 to 3 were performed 10 times as a set. The object to be measured was wood (cedar), the thickness was 40 mm, and the density was 0.35 g / cm 3 It was. Measurement 1: The object was measured while holding the moisture meter 1 by hand so as to cover almost the entire front surface of the moisture meter 1. Measurement 2: The object was measured while holding the moisture meter 1 by hand so as to cover approximately half of the front surface area of the moisture meter 1. Measurement 3: The object was measured while holding the moisture meter 1 by hand so as not to cover the front surface of the moisture meter 1 with the hand as much as possible.

[0021] The difference between the maximum value and the minimum value of the moisture content calculated in Measurements 1 to 3 was calculated. The measurement results are shown in Table 1.

[0022]

Table 1

[0023] Similar measurements were performed using a known moisture meter that has been conventionally used (hereinafter sometimes referred to as a conventional moisture meter). The measurement results are shown in Table 2.

[0024] The conventional moisture meter used was the HS-100 (model) manufactured by Micro Measurer Co., Ltd. FIG. 6 is a perspective view of the conventional moisture meter. FIG. 7 is a rear view of the conventional moisture meter. The conventional moisture meter is a high-frequency moisture meter that calculates the moisture content of an object by measuring the capacitance between a + electrode and a - electrode provided on the back as shown in FIG. 7.

[0025]

Table 2

[0026] When using the moisture meter 1 of this embodiment, the difference value between the maximum value and the minimum value among Measurements 1 to 3 (Table 1) is clearly smaller than the difference value between the maximum value and the minimum value among Measurements 1 to 3 when using a conventional moisture meter (Table 2). From this, it can be said that the moisture meter 1 of this embodiment can measure the moisture content of the object with high accuracy even when the user holds the moisture meter 1 by hand.

[0027] As described above, the present invention has been described in detail. However, the present invention is not limited to the above-described embodiments, and various changes, improvements, etc. are possible without departing from the gist of the present invention.

Explanation of Reference Numerals

[0028] 1: Moisture meter 2: Housing 31: + Electrode 32: - Electrode 33: Ground electrode 4: Display unit 5: Operation unit

Claims

1. A moisture meter that measures the capacitance between a positive electrode and a negative electrode to calculate the moisture content of an object, a ground electrode electrically connected to the negative electrode; The earth electrode is in contact with the skin of the user when measuring the capacitance of the object. Moisture meter.

2. A housing is further provided, the + electrode, the - electrode and the earth electrode are provided on a surface of the housing, Each of the + electrode and the - electrode is provided on a first surface, which is one surface of the housing; The earth electrode is provided on a surface of the housing other than the first surface. The moisture meter according to claim 1 .

3. The housing has a substantially rectangular parallelepiped shape, the ground electrode is provided on a second surface of the housing adjacent to the first surface, The + electrode, the - electrode and the earth electrode each have an elongated shape extending in the same direction. The moisture meter according to claim 2.

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