JPS61194341A - Apparatus for measuring water content - Google Patents

Abstract

PURPOSE:To make it possible to easily and certainly perform the replacement of a humidity sensor when the humidity sensor generates trouble or damage during use, by providing the humidity sensor in a detachable manner. CONSTITUTION:In a probe for detecting the humidity of a specimen to convert the same to an electric signal, a humidity sensor 16 for sensing the moisture of hair through the close contact therewith is attached to a metal support stand 68 by a screw 75 in a detachable manner. The signal detected by the humidity sensor 16 is transmitted and inputted to a signal base board 71 by the connectors 76a, 76b provided to the end part of said sensor 16. Exterior members 12, 13, 14 formed of a synthetic resin have structural assemblies 59, 60, 61 for closely contacting hair with the sensor part. The arm 65 attached to an angle 67 by a shaft 70 through a coil spring 69 has action for holding a specimen.

Description

[Detailed Description of the Invention] <Technical Field of the Invention> The present invention relates to a moisture content measuring device that measures the capacitance of a test object such as hair or fibers using a humidity sensor to measure the moisture content of the test object. be.

<Prior art> In conventional moisture content measuring devices of this type, a humidity sensor that measures the capacitance of a test object such as hair or fibers is fixed to a measuring part such as a probe, and the humidity sensor is used for this purpose. There was a drawback that even if the device broke down or was damaged, it could not be easily and reliably replaced.

<Object of the invention> The purpose of the present invention is to provide a moisture content measuring device that eliminates the above-mentioned drawbacks. ◎〈Embodiments of the invention〉 The following is an example of the moisture content measuring device of the present invention. will be explained with drawings.

FIG. 1 is an external perspective view showing an embodiment of the moisture content measuring device of the present invention. In FIG. 1, an ia main body case and an internal diagram of the main body case l show a control circuit.

Built-in display circuit. Reference numeral 2 denotes a panel for displaying the lighting position of the LED display section 3 in percentage (%), and the display contents of the panel 2 divide the percentage display to clarify the characteristics of the object to be measured, such as hair or fibers. . In this example, in order to clarify the characteristics of the subject, the display contents of panel 2 in this example are 6-9% dry, 10-14%
It is divided into three parts: normal (15% to 17%) and wet (15% to 17%), and each of the three divisions is clearly distinguished by the color of the arrow mark 4 on the panel 2. In addition, the classification display has been changed on panel 2 (dry due to relative humidity).

A knob 5 is provided for changing the classification between normal and wet. 6 is an indication of the relative humidity range (for example, the relative humidity is classified into three levels: 30 degrees or less, 30 degrees to 80%, and 80 degrees or more. This category is determined by testing based on the performance of this device), and the measurement By moving the hour knob 5 to the position corresponding to the relative humidity at the time of measurement, the measurement results are displayed in appropriate categories. 7 is a power cord for connecting the control circuit etc. of the main body case 1 to the power supply, and 9 is a curl that transmits the signal of the measuring section (sensor section) 10 to the control circuit inside the main case L, considering ease of use and storage efficiency. code, 12, 13
．． Reference numeral 14 denotes an exterior member made of synthetic resin that constitutes the probe 15 of the measurement unit 10. The exterior member 13 has a function of sandwiching the subject with the exterior member 14 by an internal coiled spring, and is provided on the exterior member 14. It has a function of pressing the subject against the humidity sensor 16. Further, when the probe 15i of the measurement section 10 is not in use, it is stored in a storage section 17 formed at the rear of the main body case l. 18 (f'i is a switch operation section for holding the measured value.

FIG. 2 is an exploded perspective view of the main body part shown in FIG. 1. In FIG. Corresponding to the positional relationship, there are LED light leak holes 209 and concave grooves 22 at the bottom of the division display belt 21. Power switch hole 23
．． Light leak hole 25 for power display LED 24. Operation section 27 of the hold switch (switch for fixing the measured value for a short time) 26. A light leak hole 29 for the hold display LED 2B is provided. The above classification display belt 21 is installed by fitting it into the mounting groove 22 of the main body case l, then fixing the panel 2 to the main body case l, and attaching the knob 5 to the rising part 31 provided at the end of the classification display belt 21. Insert and complete. Also, the concave groove 22 for attaching the classification display bell) 21fl
By moving the knob 5 along the relative humidity display section 6, the display classification of the object changes by several inches (the color display section of the panel 2 changes) to correct the influence of the ambient humidity of the object. become. The panel 2 also has a light leak hole 33 for the display LED. Power switch cover mounting hole 3
4. An operation display section 36 for the hold switch 26 is provided. Inside the main body case l, a main board 38 on which a control circuit is set and a memory display board 40 on which a display LED 39 is set that lights up in response to a signal from the control circuit are installed. The main board 38 has transformers 41° IC42 and 43.
・44. Resistance 45. Parts such as a capacitor 46 are attached, and a power cord 7 and a curl cord 9 from the probe 15 are connected to form a predetermined circuit. The signal from the control circuit is connected to the connector 48 and the cable 4.
A signal is transmitted to the display substrate 40 via 9. The display board 40 also includes a power switch 50 for turning on and off the power. Power display LED (energization display LED) 24
, hold switch 26. Hold operation display LED28
The display board 10 is attached to the main body case l with a plurality of screws 52. The main board 38 also includes a back cover 53 and a plurality of insulating spacers 54, which constitute the external force on the bottom of the main body case 1. Bis55.
It is attached by a nut 56. A plurality of legs 57 made of a soft material such as rubber and having a suction function are attached to the main board 38 in order to prevent scratches on the mounting surface of a desk or the like and to prevent movement of the instrument (main body). There is.

FIG. 3 is an exploded perspective view of a probe for detecting the humidity of a subject and converting it into an electrical signal.
6 is a humidity sensor that detects moisture by contacting the hair, 12
．． 13,14tIi This is an exterior member made of synthetic resin, and the exterior member 12.13.14id is made of the following metals.
Contains synthetic resin parts. 59.60,611ri This is a structural assembly for bringing hair into close contact with the sensor portion of the exterior member 12.

59 is a holding plate made of synthetic resin with multiple screws 62
It is attached to the metal mounting plate 60 at. The metal mounting plate 6
0 has rising sections 63 at both ends, and the shaft 61 is passed through a mounting hole 64 provided in the sections 63 to be attached to an arm 65. The arm 65 has a mounting hole at the end opposite to where the metal mounting plate 60 is mounted. Mounting angle 67
is attached to a metal support 68, and a coiled spring 6 is attached so that the arm 65 exerts a holding effect on the subject.
The arm 65 is attached to the shaft 70 through a coiled spring 69 so that the arm 65 exerts a holding effect through the shaft 70 through the spring 9 . In addition, the metal support base 68
There is a signal board 71 in which a circuit for converting the humidity of the subject into an electrical signal is set, and a metal plate 72 below the signal board 71 for shielding the stray capacitance of the signal board 71. There is a protruding section 73 at the end of the metal plate 72, and this section contacts the ground line of the signal board 71 to perform its function. The arm 65 has an exterior member 60
is attached, and the humidity sensor 16 is detachably attached to the metal support base 68 with screws 75. The signals detected by the humidity sensor 16 are transmitted to the signal board 71 through connectors 76a and 76b provided at the ends, and are input to the signal board 71. The input of the signal board 71 is connected to a connector 79 connected to the end 78 of the curl cord 9 by a connector 77 on the output side, and is connected to the main board 38 of the main body case l via the connector 79 and the curl cord 9. connector 80
The signal is transmitted to the control circuit of the main board 38. Further, the exterior member 59 and the exterior member 61 are connected by screws 81.
The agreement will be concluded. 82 is a screw that attaches the back cover 53 to the main body case L; 83 is a power switch cover;
'i is an insulating spacer, and 85 is a mounting screw.

FIG. 4 is a block diagram showing the electric circuit of the moisture content measuring device of the present invention. In FIG. It is formed by two electrodes 90 and 91 planes,
When a subject such as hair comes into contact with the surfaces of these electrodes 90.91, the dielectric constant between the electrodes 90.91 changes, thereby changing the capacitance between the electrodes 90.91. Here, the relationship between the moisture content of the hair, which is the subject, and the capacitance of the sensor when the hair tJ1 is sandwiched between the sensor portion of the probe 15 is shown in FIG. in this case.

The moisture content of hair was measured by gravimetric method.

In this way, the higher the moisture content, the larger the capacitance of the sensor, which is almost in direct proportion to the sensor.This type of sensor with variable capacitance can be regarded as a type of variable capacitor, and when combined with a fixed resistor, oscillation can be achieved. A circuit can be formed to convert capacitance changes into frequency changes. 93#: is a capacitance/frequency conversion circuit that converts the capacitance change into a frequency change.

The capacitance/frequency conversion circuit 93 is provided in the probe 15. The frequency signal converted by the capacitance/frequency conversion circuit 93 is transmitted to the frequency/voltage conversion circuit 94 of the main body via the curl cord 9. In this case, since it is converted into a frequency signal (converted to digital) and transmitted, an accurate signal value that is resistant to noise and has no attenuation is transmitted.The frequency signal transmitted to the frequency/voltage conversion circuit 94 is The voltage conversion circuit 94 converts it into a voltage (analog) signal proportional to the frequency and applies it to the voltage signal amplification circuit 95.The voltage signal applied to the voltage signal amplification circuit 95 has a large amount of change in the voltage signal. Since the voltage is small, only the necessary portion (region where the voltage changes) is increased and the voltage signal is amplified into a voltage signal whose amount of change is easy to determine.The sensor surface state memory circuit 96
and is applied to the voltage signal storage circuit 97. The sensor surface state memory circuit 96 (the applied voltage signal is
5 open state (nothing is in contact with the sensor surface)
It is temporarily stored as a voltage signal when it is in an open state. Further, the voltage signal applied to the voltage signal storage circuit 97 is
When the display of the LED lamp becomes stable with the hair being held between the terminals 5 and 5, the current display is memorized so that it can be held for about 10 seconds by pressing the hold button (hold switch) 98. In this case, after pressing the hold button 98, the display can be checked for a while even if the subject's hair is removed from the probe 15. , in the case of Matako, hold button 98
The display will be released after 10 seconds after pressing .

The voltage signals from the surface state storage circuit 96 and voltage signal storage circuit 97 are applied to a voltage signal difference detection circuit 99. The voltage signal applied to the voltage signal difference detection circuit 99 detects the difference between the voltage signal in the open state and the voltage signal in the measurement state in which the probe 15 is holding hair as a test object, and detects the difference in the voltage signal when the sensor surface is dirty. Even if the ambient humidity changes due to the weather, air conditioning equipment, etc., the condition of the sensor surface at that time is detected each time, and the voltage signal/display value conversion circuit detects the correct moisture content of the hair, which is the subject being tested. 100 is applied. The voltage signal applied to the voltage signal/display value conversion circuit 100 is compared with a reference voltage signal for each water content obtained through experiments to identify the display value, and is converted into a predetermined display signal to be used in the LED lamp. It is applied to the operating circuit 101. Based on the display signal applied to the LED lamp operating circuit 101, the 12 LED lamps 39 are turned on to display the moisture content in 1% increments from 6% to 17% to display the moisture content of the hair to be examined.

The operating state of the moisture content measuring device configured as described above will be explained with reference to FIG.
The signal is temporarily stored in a sensor surface state storage circuit 96 via a capacitance/frequency conversion circuit 93, a curl code 99, a frequency/voltage conversion circuit 94, and a voltage signal amplification circuit 95. The voltage signal in the measurement state of the soldered state is sent to the humidity sensor 16. Capacitance/frequency conversion circuit 93. Curl code 91 frequency/voltage conversion circuit 94. The voltage signal is applied to the voltage signal difference detection circuit 99 via the voltage storage circuit 97, and the voltage signal difference detection circuit 99 detects the difference between the voltage signal in the open state and the voltage signal in the measurement state, and displays the voltage signal/display. The value conversion circuit 1ootc is applied, and the voltage signal/display value conversion circuit 100 converts it into a prescribed display signal and outputs
A predetermined number of L of the 12 LED lamps 39 is applied in the LED lamp operation circuit 101.
The ED lamp 39 is driven to display the moisture content of the hair, which is the subject, on the panel 2. In the above case, hold button 98
By pressing , the display can be checked for a while even if the subject's hair is separated from the probe 15.

<Effects of the Invention> Since the moisture content measuring device of the present invention has the above-described configuration, the humidity sensor can be easily and reliably replaced in the event of failure or damage during use.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an embodiment of the moisture content measuring device of the present invention, FIG. 2 is an exploded perspective view of the main body of FIG. 1, and FIG.
The figure is an exploded perspective view of the probe in Figure 1, Figure 4 is a block diagram showing the electric circuit of the moisture content measuring device of the present invention, Figure 5 is an enlarged plan view of the main parts of the humidity sensor in Figure 3, and Figure 6 is an exploded perspective view of the probe in Figure 1. The figure is a characteristic diagram of the humidity sensor of FIG. 3. In the drawing, 16 indicates a humidity sensor. Agents: Patent Attorney Aihiko Fuku (and 2 others) Atsushi l

Claims (1)

[Claims] 1. A moisture content measuring device that measures the capacitance of a test object such as hair or fibers using a humidity sensor to measure the moisture content of the test object, characterized in that the humidity sensor is detachably provided. rate measuring device.