What is the Ω-range of a multimeter used to measure?
The Ω file of the multimeter is the resistance file, which is used to measure the resistance value of the resistor.
The digital multimeter with manual range change and the digital multimeter with automatic range change. Their use is very simple, the measurement of resistance, the red pen into the multimeter "VΩ" hole, the black pen into the multimeter "COM" hole, and then the multimeter's range switch to the resistance position, the red and black pens were contacted by the measured two pins can be read. The two pins of the measured resistor can be read out the resistance value of the resistor.
When measuring, for the multimeter with automatic range change, there is no need to consider the size of the resistance value, the multimeter can automatically switch to the appropriate range. For a multimeter with manual range change, it is necessary to adjust the range switch to the appropriate position according to the size of the resistance value before measurement. In addition, many manual range multimeter, the minimum resistance file can not return to zero, for example, the general 3 / ½ digital multimeter, its 200 Ω file in the red and black pens shorted, the general display of the reading in the zero point a few to one point a few Ω (the smaller the better this readings), so in the measurement of 10 Ω or less of the small resistance resistance, should be displayed in the readings subtracted from the readings of the red and black pens shorted, so that the result is the true resistance value of a small The result is the true resistance value of the small resistor.
Multimeter measurement of the control line and the switchboard connected does not affect the control loop indicator light slightly bright how to deal with the situation
According to what you said, there is a device shorted to ground, because the equipment are grounded protection, you measure, the zero line and the ground line must have voltage, otherwise the indicator will not be weakly lit. Why is it bright? Because the indicator is connected to the phase line, a pole connected to the zero line. After the phase line to ground, because the zero line and the ground line has some voltage, so that is, the phase line and the zero line has a voltage (when the power supply is disconnected), so the indicator light is slightly bright. Why is there voltage on the zero and ground lines? Because the distribution cabinet is some distance away from the transformer, there could be voltage between the grounding pole under the transformer and the grounding pole of the distribution cabinet. I get this all the time and there's nothing to do but check one device at a time.
