1. Field of the Invention
This invention relates to a test probe for a measuring instrument, such as a tester (circuit tester), and a tester incorporating the test probe.
2. Prior Art
In a measuring instrument, such as a tester which has a possibility of measuring high voltages, to prevent failure of the instrument due to a disconnection or the like and for safety purposes, it is required to prevent a mechanical force from being applied to electrically-connecting portions. To this end, in a conventional tester, the inside of a grip and covering of a lead wire are bonded to each other to prevent a mechanical force from being applied to a portion where a probe and the lead wire are soldered to each other (connecting portion) when the lead wire is pulled.
FIG. 1 shows a test probe of the conventional tester constructed as described above. In this test probe 51, a core wire 53a of a lead wire 53 is soldered to a proximal end of a probe 52, while a grip 54 having the proximal end of the probe 52 screwed to a distal end thereof and a covering 53b of the lead wire 53 are stuck to each other by an adhesive 55. As a result, even if a force for drawing the lead wire 53 out of the grip 54 is applied, the force acts on the grip 54 but does not act on the soldered portion 56.
In the conventional test probe 51 thus constructed, although a mechanical force is not applied to an electrically-connecting portion, the grip 54 and the lead wire 53 are stuck to each other, so that, when any of the component parts of the grip 54, the probe 52, the lead wire 53 and the like is broken, it is impossible to replace only the broken component part. Further, when the soldered portion 56 suffers from connection failure, it is impossible to repair the same.
Furthermore, since the probe 52 and the lead wire 53 are connected to each other by soldering, the connection operation is required to be manually carried out. This requires skills and increases manufacturing costs of the test probe, while relatively degrading the reliability of the connecting portion.