| 摘要 |
PURPOSE:To simplify measurement work and prevent the occurrence of measurement miss by disposing magnetism sensors and a high magnetic permeability yoke to a head part in a distance-variable manner, discriminating the polarity obtained by the output of this head and displaying the same. CONSTITUTION:If the leading end of the measuring head part 7 of a body is approached to the magnetic pole to be measured, and a switch 3 is closed by operating a push button 2, a power source is supplied from a battery 4 to respective Hall ICs 8, 9. At this time, a transistor 8f is turned on by the Hall voltage from the Hall element 8a and therefore an LED5 corresponding to a character N turns on a light. When the magnetic pole is of reverse polarity, the LED6 corresponding to a character S is lighted by the Hall voltage from the Hall element 9a. If a yoke 10 is moved closer to or apart from the ICs 8, 9 by operating a knob 13, the magnetic flux number of the ICs 8, 9 changes and this makes sensitivity adjustment possible. Hence, the adverse influence by the nearbly weak magnetic fields is eliminated by lowering the sensitivity and the measurement is made accurate. |
