JPH0213963Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a detection electrode for a moisture meter for measuring moisture in wood, etc., and particularly to a detection electrode for an electrical resistance moisture meter.

For example, in furniture manufacturing, it is important to measure the moisture content of wood, and for this purpose electrical resistance moisture meters are used. This electrical resistance moisture meter is connected to a detection electrode via an electrical cord, which is pressed against the surface of wood to measure the electrical resistance of the wood. There are two types of detection electrodes: a needle electrode for general wood, and a conductive rubber electrode for measuring surface finishing materials and thin plates without scratches or holes.

Needle electrodes can measure the resistance of the deep layers of wood to some extent, but since they are different from high-frequency moisture meters, they can measure moisture relatively close to the surface. Conductive rubber electrodes are used for surface finishing materials and thin sheet materials (veneer boards) when they cannot be used for surface finishing materials or thin sheet materials (veneer boards) because the needle must be inserted into the wood surface. Since the conductive rubber electrode is simply pressed against the surface of the wood, it will not damage the surface, and there is no risk of cracking even in the case of a thin plate.

For the above reasons, it is necessary to prepare two types of detection electrodes for the wood electrical resistance moisture meter: needle electrodes and conductive rubber electrodes, which is not only uneconomical but also
It is not compact and is difficult to carry.

As a solution to the above problem,
There is a U-shaped box as disclosed in Japanese Patent No. 31994 in which a display section, a needle electrode, and a conductive rubber electrode are integrally provided in three directions.

Furthermore, Japanese Utility Model Publication No. 31-11787 discloses a sensor in which a needle electrode is provided at one end of the sensing electrode and a conductive rubber electrode is provided at the other end. These devices have the disadvantage that the structure, especially the connection of the cord, is complicated and the cost is high.

This invention was created in view of the above points,
A conductor rubber is provided on the cap that covers the needle of the needle electrode, and the conductor rubber is configured to be in contact with the needle electrode, and when measuring the moisture content of surface finishing materials, etc., the cap is left attached. A sensing electrode is provided in which a conductive rubber is pressed against a surface to be measured.

The present invention provides a highly portable and economical detection electrode for an electrical resistance type wood moisture meter with the above-mentioned configuration.

The invention will be explained in more detail below in the form of an example with reference to the accompanying drawings, in which: FIG.

FIG. 1 shows a needle electrode 1, the head of which is covered with a cap 12 provided with a conductive rubber 10, which is a characteristic feature of the present invention.

In FIG. 1, reference number 2 is the grip handle of the needle electrode 1, 2' is a joint plate made of high insulation resistance material, and 3 is a round metal fitting that serves as an electrical shield.
It is electrically insulated from the connecting plate 2'.
The round metal fitting 3 holds a connection cord 15, and the wiring in the connection cord 15 is electrically connected to the needle holder 4 held by the round metal fitting 3 itself, for example, by soldering.

Reference number 7 is a needle holder receiver made of highly insulating material;
Separately provided for positive (+) and negative (-) to further improve insulation.

The needle 5 is inserted into the insertion hole of the needle holder 4, and is securely fixed with a screw 6 screwed into a side screw hole of the needle holder 4. In this embodiment, since two needle holders 4 are provided in each of the positive and negative needle holder receivers 7, there are two needles 5 in each of the positive and negative needles.

Referring to Figures 2a and 2b, cap 1
2 is provided with four conductor rubbers 10.
As can be seen in Figure 1, a cap 1 is attached to the needle electrode.
2 is attached, the tip of the needle 5 pierces the conductive rubber 10 protruding from the back side of the cap 12, so that they become electrically conductive.

Furthermore, by providing a guide bead 13 on the skirt portion of the cap 12 parallel to the axis of the cap 12 and engaging it with the split groove 8 of the needle holder receiver 7, the needle 5 can be reliably moved to the corresponding conductor rubber 10. It will be pierced.

Since the wood moisture meter ends up measuring high resistance, in order to eliminate the influence of leakage between the conductor rubber 10, as shown in Figures 3a and 3b,
A guard 14 is provided which also serves as the guide bead 13 described above, and when the cap 12 is attached, this guard 1
4 should be electrically connected to the round metal fitting 3. The round metal fitting 3 is electrically connected to the ground wire (not shown) in the connection cord 15, so the guard ring 1
4 is also grounded when the cap 12 is installed. The ground wire is also connected to the moisture meter body using a two-core shielded wire, thereby blocking any leakage current.

Preferably, the guard 14 is made of a rod having a cross-sectional shape as shown in FIG.

Further, the conductor rubber 10 can be attached to and detached from the cap 12 by providing a keyhole-shaped hole in the cap.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of the present invention, with a portion cut away to illustrate the interior for ease of understanding. FIG. 2a is a front view showing the main parts of the present invention, and FIG. 2b is a side view thereof with a portion cut away. Figures 3a and 3b are views similar to Figures 2a and 2b, illustrating a modified form thereof. Figure 4 shows - of Figure 3b.
A cross-sectional view along the line. 1... Sensing electrode, 2... Grip handle, 2'... Joint plate, 3... Round metal fitting, 4... Needle holder, 5... Needle,
6...screw, 7...needle holder holder, 8...divided groove,
10...Conductor rubber, 12...Cap, 13...
Guide bead, 14...guard, 15...connection fittings.

Claims (1)

[Scope of claim for utility model registration] (1) A plurality of needles that are held in a needle holder and pierce the surface of the wood to be measured for moisture as detection electrodes of an electric resistance wood moisture meter, and a detachable cover for the needles. In a detection electrode for an electrical resistance wood moisture meter having a freely movable cap, the cap is provided with a plurality of conductive rubbers penetrating through its top wall and arranged at positions where the plurality of needles penetrate, A sensing electrode device characterized in that it functions as a needle electrode when the cap is removed and as a conductive rubber electrode when the cap is attached. (2) The sensing electrode according to item (1) of the utility model registration claim, wherein the skirt portion of the cap is provided with a guide bead that engages with the groove of the needle holder receiver for the needle holder. (3) The cap is constructed by combining two halves through a guard, and the guard is engaged with the split groove of the needle holder receiver for the needle holder and is grounded. The first claim of the utility model registration that the positive and negative electrodes are isolated from each other
The sensing electrode described in section (1).