JPS61195341A - Water content measurement device - Google Patents

Abstract

PURPOSE:To accurately measure a water content by providing one electrode with a hot electrode and an earthing electrode on its surface and an earthing electrode via an insulating plate on the reverse side, while the other electrode with an earthing electrode through an insulating plate. CONSTITUTION:The device is provided with a pattern of a hot electrode 13 and an earthing electrode 14 having comb-like parts 12a, 12b contacting with detected objects such as hair or fiber on the front surface of the insulating plate 11 of glass or epoxy. A pattern of earthing electrodes 15 is provided on the reverse surface of the insulating plate 17 and the earthing electrodes 15, 14 are electrically connected by means of through-holes to form a lower electrode 16. An earthing electrode 18 is provided on an insulating plate 17 to form an upper electrode 19. The detected member is held between the comb- like part 12a, 12b of the earthing electrode 14, the hot electrode 13 of the lower electrode 16 and the electrode 19, and the high frequency is applied between the upper and lower electrodes 19 and 16 to measure the capacitance of the detected body to measure the water content.

Description

[Detailed Description of the Invention] <Technical Field of the Invention> The present invention measures the capacitance of a test object such as hair or fibers by holding the test object between electrodes and applying a high frequency between the electrodes. The present invention relates to a moisture content measuring device for measuring the moisture content of the above-mentioned subject.

<Prior art> As shown in Figures 1 and 2, the conventional moisture content measuring device has a hot electrode 1 and a ground electrode 2 arranged on a lower electrode 4 on an electrically insulating plate 3, and a lower electrode 4 on an electrically insulating plate 5. It consists of an upper electrode 7 with a ground electrode 6 arranged thereon, a specimen 8 such as hair or fibers is held between the upper electrode 7 and the lower electrode 4, and a high frequency is applied between the upper electrode 7 and the lower electrode 4. The structure is such that the water content is measured by detecting the capacitance of the subject 8.

With the water content measuring device configured as above, the capacitance is affected by the dielectric constant of all substances existing between the hot electrode 1 and the earth electrode 2, and therefore the stray capacitance due to disturbances near the electrodes. If a change occurs, accurate moisture content measurement cannot be performed, so the fixing base 9 that fixes the lower electrode 4 is made of a conductive material and connected to the ground electrode 2 for shielding. Insulation plate 3
Due to distortion of the flat surface of the fixing base 9, the insulating plate 3 and the fixing base 9
It is difficult to completely bring them into close contact with each other, and the resulting gap between the insulating plate 3 and the fixing base 9 causes a change in capacitance, making accurate measurement impossible.

<Object of the Invention> The present invention will be explained with reference to the water content diagrams to FIG. 3, which eliminate the above-mentioned drawbacks.

The water content measuring device of the present invention has a hot electrode having comb-shaped parts 12m and 12b that come into contact with a subject such as hair or fibers on the surface of an electrically insulating plate 11 made of a glass epoxy material, etc. A pattern of a ground electrode 13 and a ground electrode 14 are arranged, and a pattern of a ground electrode 15 is arranged on the back surface of the electrically insulating plate 11 as shown in FIG.
5 and the ground electrode 14 are electrically connected through a through hole to form a lower electrode 16, a ground electrode 18 is disposed on an electrically insulating plate 17 to form an upper electrode 19, and the upper electrode 19 and the above A subject such as hair or fibers is held between the hot electrode 13 of the lower electrode 16 and the comb-shaped parts 12a and 12b of the ground electrode 14, and a high frequency is applied between the upper electrode 19 and the lower electrode 16 to test the subject. The structure is such that the water content is measured by detecting (measuring) the capacitance of the sample.

By providing the ground electrode 15 on the back surface of the lower electrode 16 as described above, if the thickness of the electrically insulating plate 11 is kept constant, there will be no gap created when the lower electrode 16 and the fixing base 20 are attached (fixed). Regardless of the situation, the capacitance between the hot electrode 13 and the ground electrode 14 is kept constant, allowing accurate measurement, and the ground electrode 15 on the back side of the lower electrode 16 acts as a shield to reduce the influence of external disturbances. can be removed and stable water content measurements can be made.

<Effects of the Invention> Since the moisture content measuring device of the present invention has the above-described configuration, it is possible to reliably prevent changes in capacitance when measuring the moisture content of a specimen, and to measure the moisture content of the specimen. can be measured accurately, and mass productivity can be improved because the presence or absence of a gap that sometimes occurs when attaching the lower electrode to the fixing base has no bearing on changes in capacitance during measurement.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional model diagram showing one embodiment of the water content measuring device of the present invention, FIG. 2 is a front view of the lower electrode in FIG. 1, and FIG. 3 is a back view of the lower electrode in FIG. 1. FIG. 4 is a cross-sectional model diagram showing an example of a conventional moisture content measuring device, and FIG. 5 is a cross-sectional model diagram showing a state of measurement of the moisture content of a subject using an example of the conventional moisture content measuring device. . In the drawing, 11 is an electrical insulating plate, 13 is a hot electrode, 14 is a ground electrode, 15 is a ground electrode, 16 is a lower electrode, 17
18 is an electrically insulating plate, 18 is a ground electrode, and 19 is an upper electrode. Agent: Patent attorney Aihiko Fukushi (and 2 others) Figure 2, 3rd flash

Claims (1)

[Claims] 1. In a water content measuring device that holds a test object such as hair or fiber between electrodes and measures the capacitance of the test object by applying high frequency between the electrodes to measure the water content of the test object. , one of the electrodes has a hot electrode and a ground electrode on the front surface and a ground electrode on the back surface with an insulating plate in between, and the other electrode has a ground electrode with an insulating plate in between. A moisture content measuring device featuring: