JPS5848617Y2 - Sensitivity setting rod - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sample rod necessary for setting the sensitivity of flaw detection products and iron powder detectors.

Devices for detecting flaws on the surface of copper wire using eddy current testing and for detecting iron powder in copper wire using magnetism both consist of a detector body and a detection coil.

As a method of checking the true detection sensitivity of these devices, as shown in Figures 1 and 2, a metal rod 1 made of copper wire with actual flaws or copper wire mixed with iron powder is inserted into the coil hole 2 of the detection coil 2.
At present, a good method is to insert it into `` and move it back and forth to find its detection sensitivity.

However, when actually carrying out this work, there is naturally a gap between the inner diameter of the coil hole 2' and the outer diameter of the metal rod 1, so it is necessary to insert it at an angle as shown in Fig. This has the disadvantage that it is very difficult to set the true sensitivity, and that settings vary from person to person.

In order to eliminate such drawbacks, the sensitivity setting rod of the present invention has the outer circumference of a metal rod serving as a sample coated with a non-magnetic non-metal, and the outer diameter of the non-magnetic non-metal and the inner diameter of the detector hole through which the metal rod is passed. and provide sensitivity setting rods that closely match.

As shown in FIG. 3, the metal rod 1 is a so-called sample, such as a copper wire with flaws on its surface or a copper wire with iron powder inside, and its outer periphery is coated with a non-magnetic non-metal 3. .

The non-magnetic non-metal 3 is made by, for example, wrapping a paper string around the metal rod 1 in a spiral shape, hardening it with epoxy resin or covering it with a shrink tube, and the sensitivity setting rod is connected to the coil hole 2'.
Its outer diameter is such that it passes through the coil hole 2' of the detection coil 2.
It almost matches the inner diameter of.

After adjusting the detection level of the detection coil 2 with the sensitivity setting rod passing through the center of the coil hole 2',
The test is carried out by continuously passing a rolled and drawn metal wire similar to that of the metal rod 1.

The sensitivity setting rod of the present invention has a metal rod 1 serving as a sample coated with a non-magnetic non-metal 3, but even with the non-magnetic non-metal 3 there is no practical problem in detection accuracy.

Further, the metal rod 1 has the same outer diameter as the metal wire to be detected, for example, 1, 5 mm, 2.0 mm, 2.3 mm, 2
゜6mm and 3.2mm, while the inner diameter of the coil hole 2' is 4.5mm, and this outer diameter difference is coated with a non-magnetic non-metal, making it difficult to bend even a relatively thin metal rod. ing.

As described above, since the sensitivity setting rod of the present invention always passes through the center of the coil hole, there are no individual differences in the adjustment of the detection level, and the effect of maintaining stable detection accuracy is extremely large.

In addition, although the metal rod serving as the sample is coated with a non-magnetic non-metal, the metal rod itself does not slip and can be used for a long period of time, which is highly effective.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing how a metal rod serving as a conventional sample is used, and FIG. 3 is a cross-sectional view showing how the sensitivity setting rod of the present invention is used. The numbers used in the drawings are commonly used; 1 indicates the metal rod, 2 indicates the detection coil, 2' indicates the coil hole, and 3 indicates the nonmagnetic nonmetal.

Claims (1)

[Scope of utility model registration request] 1. A sensitivity setting rod characterized in that the outer circumference of a metal rod serving as a sample is coated with a non-magnetic non-metal, and the outer diameter of the non-magnetic non-metal almost matches the inner diameter of a hole in a detector through which the metal rod is passed. . 2. The sensitivity setting rod as recorded in Paragraph 1 of the Utility Model Registration Claim, wherein the non-magnetic non-metal is a spirally wound paper string hardened with epoxy resin or a shrink tube.