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| Effective Measuring Range of Insulation Tester |
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The measuring range for which the accuracy of an insulation tester is guaranteed. There are two kinds of effective measuring ranges: the first and second effective measuring ranges.
First effective measuring range
From 1/1000 to 1/2 the maximum effective scale value
(When there is no major scale division for 1/2 the maximum effective scale value, the nearest major scale division is used.)
Second effective measuring range
Scales divisions not included in the first effective measuring range
For example for a 500V/100MΩ insulation tester;
First effective measuring range: 0.1-50MΩ(±5% of indicated value)
Second effective measuring range: 50-100MΩ(±10% of indicated value)
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The ratio of the effective value to the average value.
Form factor = Effective value/Average value
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The manner in which a device changes its output quantity it, its indication for a measured quantity or its response over a range of frequencies.
AC signals to measure with a tester can be of one frequency or from a wide frequency band ranging from low to high frequencies. To measure these frequencies, it is better to use a tester having a wide frequency response range. |
When a current-carrying conductor is placed in a magnetic field so that the direction of the magnetic field is perpendicular to the direction of the current flow, voltage is developed in the direction perpendicular to both the magnetic field and the current flow. This is called the Hall effect and the Hall element is a device that utilizes the effect.
Kyoritsu AC/DC clamp meters and clamp sensors employ the Hall element.
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Power line AC voltage from a utility company has near sinusoidal waveform of fundamental frequency with little distortion. When only a load consisting of resisters, capacitors and coils, called a linear load (its constant is fixed regardless of the amount of current flowing through it), is connected to mains supply, no distortion is introduced into the load current waveform. However, when a non-linear load, such as a semiconductor and a saturable reactor, is connected, distortion appears in the load current waveform. The current with a waveform containing distortion, or harmonic current, flows in the direction toward the low impedance side and in the process, produces voltage drop over the impedance of the current path, causing the load voltage also to contain harmonics.
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| The value indicated by a tester for a measured quantity |
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