JPH028202Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rod-shaped electrode for a device for measuring moisture in particulate matter.

Moisture measuring devices with rod-shaped electrodes can be used to measure grains, sand,
It is suitably used to measure the moisture content of granular materials such as cement, fertilizer, and synthetic resin powder. For example, a moisture measuring device is already in use that measures the electrical characteristics of coffee beans packed in a jute bag by inserting a rod-shaped electrode into the coffee beans, and then calculates the moisture content of the coffee beans.

This rod-shaped electrode is constituted by a positive electrode with a sharp tip, an insulator, and a negative electrode arranged linearly in this order from the tip to form a rod shape.
The electrical characteristics of the particulate matter are detected between the positive and negative electrodes, and the water content of the particulate matter is then measured.

However, the conventionally used rod-shaped electrodes have the following two drawbacks. First, when fine water droplets adhere to the surface of the insulator of the rod-shaped electrode due to moisture or the like, a leakage current flows between the positive electrode and the negative electrode, which deteriorates the degree of insulation between these electrodes. for example,
In Africa's coffee bean producing regions, the temperature is 40 degrees Celsius and the humidity is 90%.
It is a hot and humid area, and in such an environment, a weak current flows through the electrode section before measurement, and the meter does not show a zero value. Even if this is adjusted to zero, accurate moisture measurement cannot be expected. Moreover, the water content (electrical resistance) of coffee beans is 6% to 18%.
% (700000~7MΩ) cocoa beans 4%~14%
(800,000 to 40 MΩ), and in order to measure this accurately, it is essential to take measures against moisture in the moisture measuring device, including the rod-shaped electrode.

Therefore, the rod-shaped electrodes of conventional moisture measuring devices have had problems with their accuracy when measuring in humid locations. Second, in order to reduce costs and ease the assembly process, conventional rod-shaped electrodes use hollow material spliced to other members except for the tip electrode, which has the disadvantage of being easily broken.

The present invention provides a rod-shaped electrode for a moisture measuring device that solves the above problems, that is, it provides a rod-shaped electrode that enables highly accurate moisture measurement even in humid places.

According to the present invention, in a rod-shaped electrode for a moisture measuring device, which is configured in a rod shape by linearly arranging a positive electrode with a sharp tip, an insulator, and a negative electrode, two insulators are linearly arranged. consists of two insulators,
A rod-shaped electrode for a moisture measuring device is provided, characterized in that a ground electrode is provided between two insulators. Another feature of this invention is that the positive electrode with a sharp tip is a threaded rod (rod-shaped conductive material) that also serves as a lead wire.
However, each of the ground electrode and the negative electrode has a similar pipe material (tubular conductive material) that also serves as a lead wire extending through an insulating tube to the handle attachment portion, thereby providing a reinforcing structure.

The present invention is described below in the form of an embodiment together with the accompanying drawings.
Explain in detail.

FIG. 1 shows a rod-shaped electrode of a moisture measuring device which is an embodiment of the present invention, and reference number 1 is a conical positive electrode with a sharp tip. Screw hole 10a in the center of the recess 10
The threaded tip of the rod-shaped conductive wire 1' is screwed into the rod-shaped conductive wire 1'. The positive electrode 1 and this rod-shaped conductive wire 1' are arranged coaxially. This rod-shaped conductive wire 1' is covered with an insulating tube 6 made of heat-shrinkable material. A first tubular insulator 3 is provided on this insulating tube 6 adjacent to the positive electrode 1 . First tubular insulator 3
The tip on the positive electrode side has a small diameter, and this small diameter portion is fitted into the recess 10 of the positive electrode 1 to ensure the connection. Further, a two-stage stepped recess 11 is provided at the rear end of the first tubular insulator 3. It has a tip that is complementary to the two-stepped recess. A ring-shaped earth electrode 5 attached to the tip of the tubular conductor 5'
is fitted onto the insulating tube 6 and fitted into the first tubular insulator 3. The rear end of this ring-shaped earth electrode 5 has a small diameter, and from the rear end surface,
A tubular conductor 5' integral therewith extends coaxially over the rod-shaped conductor 1'.

The tubular conductor 5 is further covered with a heat-shrinkable large-diameter insulating tube 7. A second tubular insulator 3a of approximately the same type as the first tubular insulator 3 having a tip complementary to the rear end surface of the ground electrode 5 is fitted onto the large diameter insulating tube 7, and the tubular negative electrode 2 is further passed through. It is fitted into the rear end of the second tubular insulator 3a. A cylindrical conductor 2' integral with the negative electrode 2 extends rearward from the rear end of the negative electrode 2 coaxially with the tubular conductor 5' and the rod-shaped conductor 1'.

The rear part of the rod-shaped electrode is fitted into the handle holder 20, and the rod-shaped conductor 1', the tubular conductor 5', and the cylindrical conductor 2' are exposed in this order, and are connected by nuts 21, 25, and 22, respectively. It is connected to conductors 28, 27, and 26 of the circuit on the measuring device side. Note that insulating washers 23 and 24 are provided on each nut tube to prevent electrical contact between the respective conductors.

Reference number 9 in the drawings is a cylinder made of an insulating material that constitutes the outer shell of the rod-shaped electrode. In this embodiment, the rod-shaped electrode has the same diameter over its entire length, except for the sharp tip of the positive electrode 1.

FIG. 2 is a block diagram of a moisture measuring device using a rod-shaped electrode according to the present invention.

Positive and negative electrode terminals 26, 28 and earth electrode terminal 27
are connected to the positive and negative terminals 31, 32 and the ground terminal 33 of the moisture measuring device using a 3-core shielded cord, respectively.
It is becoming connected to. Note that the ground terminal 33 is connected to the box 34 of the moisture measuring device.

Although the present invention has been described in detail in the form of embodiments, the present invention is not limited to the form of the above-mentioned embodiments, but can be modified in various ways within the technical scope described in the claims of the utility model registration. For example, the connection of the positive electrode and negative electrode can be reversed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the tip and rear ends of a rod-shaped electrode according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a block diagram of a moisture measuring device using a rod-shaped electrode of the present invention. 1... Positive electrode, 2... Electrode, 3, 3a... Insulator, 5... Earth electrode.

Claims (1)

[Claims for Utility Model Registration] (1) A rod-shaped electrode for a moisture measuring device in which a positive electrode, an insulator, and a negative electrode are arranged linearly in a rod shape, and the insulator is linearly arranged. A rod-shaped electrode for a moisture measuring device comprising two insulators and a ground electrode provided between the two insulators. (2) The rod electrode according to item (1) of the utility model registration claim, wherein the positive electrode has a sharp tip.