JPH0311749Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a ground resistance meter using an alternating current potential difference method.

As schematically shown in FIG. 1, this type of ground resistance meter includes a dial 1 connected to a variable resistor, a galvanometer 2, a range selector switch 3,
It is equipped with a power switch 4. The measurement is carried out by setting the pointer of the galvanometer 2 to 0 while turning the dial 1 with the power switch 4 pressed, and reading the scale of the dial 1 at the current position of the indicator 5. However, in this earth resistance meter, although the dial 1 and the galvanometer 2 are placed side by side as shown, the movement of the line of sight when reading the scale on the index 5 after balancing the galvanometer 2 is difficult. Therefore, it was difficult to read the scale on the indicator 5 while checking the movement of the pointer of the galvanometer 2. Furthermore, although it is desired that the on-site measuring device be made smaller, as mentioned above, the dial 1 and the galvanometer 2 are arranged in parallel and independently, which requires installation space and is an impediment to miniaturization. I was getting used to it.

Therefore, the purpose of this invention was to provide a ground resistance meter that allows you to read the scale of the dial without moving your line of sight when you turn the dial to balance the galvanometer, and that is suitable for downsizing the device. It's about doing.

Next, an embodiment of this invention will be described with reference to FIG. 2 and subsequent figures.

As shown in FIGS. 2 and 3, the ground resistance meter 11 according to this invention includes a dial device 12 and a galvanometer 13, which are placed oppositely on a housing 14. Dial device 12
has a variable resistor 15, the shaft 16 of which extends outward from the through hole 17 of the housing 14,
It is tightened and fixed by a nut 18. The shaft 16 has a set screw 2 inserted into a screw hole 20.
1, a dial knob 19 is integrally attached. A donut-shaped dial plate 22 is attached to the outer periphery of the dial knob 19 so as to be orthogonal to the axis passing through the shaft 16. This dial plate 22 is provided with a dial scale 23 indicating resistance values displayed along its outer periphery. On the other hand, the galvanometer 13 has a movable part 24 that includes a movable coil, for example, and in this embodiment, the movable part 24 is fitted into a recess 25 of the housing 14. The movable part 24 also includes a pointer 2.
6 is attached, and its tip extends so as to overlap above the dial plate 22. A housing 14 located below the pointer 26
A scale plate 27 made of a transparent material is attached to the surface, and a galvanometer scale 28 is attached to this plate, and in this case, the 0 point is the reading position of the dial scale 23. It is located in Further, the scale plate 27 extends so that a portion thereof overlaps above the dial plate 22, and a vernier scale 29 is attached to a portion along the outer periphery of the dial plate 22. Furthermore, a transparent cover 30 is placed over the galvanometer 12. By the way, when the dial knob 19 is rotated, the pointer 26 moves in accordance with the rotation of the dial knob 19 using a known circuit. For example, when the dial knob 19 is rotated clockwise, the pointer 26 is rotated counterclockwise.

In the above configuration, the dial plate 22
A portion of the dial 23 is covered above by a scale plate 27 and a transparent cover 30, and since both are made of transparent material, the dial scale 23 can be read through them. In this case, the vernier scale 29 attached to the scale plate 27 is adjacent to the dial scale 23, and the tip of the pointer 26 is adjacent to the dial scale 23.
overlaps with In the measurement operation, first, turn the dial knob 19 in a predetermined direction to align the pointer 26 with the 0 point on the galvanometer scale 28. In this case, when the dial knob 19 is rotated, the pointer 26 moves in the opposite direction. Since it rotates in the direction, pointer 2
It is only necessary to rotate the dial knob 19 in the direction in which 6 approaches the 0 point, making it easy to operate intuitively. After setting the pointer 26 to the zero point in this way, it is sufficient to read the dial scale 23 located at the tip of the pointer 26. In this case, if the vernier scale 29 is used, the indicated value can be read more precisely. In this way, the dial scale 23 of the dial device 12 is directly read by the pointer 26 of the galvanometer 13, so there is almost no need to shift your line of sight, and you can check whether the pointer 26 has deviated from the zero point. You can read it while checking it.
Further, since the dial device 12 and the galvanometer 13 are arranged close to each other, it is suitable for downsizing the device.

Another embodiment is shown in FIG. 4, in which a ground resistance meter 11' has a dial plate 22' of a dial device 12 located above a galvanometer 13. In this case, the dial plate 22' is made of a transparent material, and the pointer 26 located below it is visible through the transparent cover 30 and the dial plate 22'.

Note that this invention is not limited to the above-described embodiments; for example, the dial device 12 and the galvanometer 13 may be arranged vertically facing each other on the surface of the housing 14.

As is clear from the description of the embodiments described above, according to this invention, the galvanometer and the dial device are arranged abutting each other so that their parts overlap,
By using the galvanometer pointer as an index of the dial device, it is easy to operate the dial knob when setting the pointer to the zero point, and the ground resistance to be measured can be measured at the tip of the pointer when adjusting the zero point. can be given instructions. Therefore, there is almost no need to shift your line of sight, and you can read the measured value while checking whether the pointer has deviated from the zero point.
Extremely practical. Furthermore, since the galvanometer and the dial device are placed close to each other, it is suitable for downsizing the device.

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional earth resistance meter, Figure 2
The following figures show examples of this invention; Figure 2 is an enlarged front view of the main parts of the earth resistance meter according to this invention;
FIG. 3 is a sectional view taken along the - line, and FIG. 4 is an enlarged sectional view of a main part showing another embodiment. In the figure, 11 and 11' are earth resistance meters, 12 is a dial device, 13 is a galvanometer, 14 is a housing, and 1
9 is a dial knob, 22, 22' is a dial plate, 23 is a dial scale, 26 is a pointer, 27
28 is a scale plate, 28 is a galvanometer scale, and 29 is a vernier scale.

Claims (1)

[Claims for Utility Model Registration] (1) In an AC potentiometer type grounding resistance meter that includes a galvanometer and a dial device for balancing the galvanometer, the galvanometer and the dial device are , a part of which overlaps with each other, and the pointer of the galvanometer is arranged oppositely to serve as an index with respect to the dial plate of the dial device, and the dial device is operated to balance the galvanometer. In the earth resistance meter, the pointer indicates a measured earth resistance value on a scale of the dial plate. (2) In claim 1 of the utility model registration, the direction of rotation of the dial of the dial device and the direction of rotation of the pointer accordingly are opposite to each other as a pair of meshing gears. A ground resistance meter featuring: (3) Utility Model Registration The earth resistance meter according to Claim 1, characterized in that a vernier scale is provided adjacent to the outer periphery of the dial plate of the dial device.