The two red and black pens of the multimeter, which holes are inserted in the multimeter?
The pens of the multimeter are divided into red and black. The red pen should be inserted into the jack marked with "+" and the black pen into the jack marked with "-".
The main performance index of the multimeter basically depends on the performance of the meter head. The sensitivity of the head refers to the DC current value flowing through the head when the pointer of the head is deflected to full scale, the smaller this value is, the higher the sensitivity of the head is. The greater the internal resistance when measuring voltage, the better its performance.
Precautions:
1, the multimeter is damaged in most cases because of the measurement of the wrong gear caused by, such as in the measurement of AC utility, the measurement of the gear selection is placed in the resistance block, in this case, once the pen contact with the utility, instantly can cause damage to the internal components of the multimeter.
Therefore, before using the multimeter to measure, you must check whether the measurement position is correct. At the end of the use, the measurement selection will be placed in the AC 750V or DC 1000V, so that in the next measurement, no matter what parameters are measured by mistake, it will not cause damage to the digital multimeter.
2,Some digital multimeters are damaged because the measured voltage and current exceed the range. Such as in the AC 20V gear measurement of utility power, it is easy to cause damage to the digital multimeter AC amplifier circuit, so that the multimeter loses the AC measurement function.
When measuring DC voltage, the measured voltage exceeds the measuring range, which is also easy to cause the failure of the internal circuit of the meter. When measuring current, if the actual current value exceeds the range, it will only cause the fuse in the multimeter to blow, and will not cause other damages.
Therefore, when measuring voltage parameters, if you don't know the approximate range of the measured voltage, you should first put the measurement gear in the highest grade, and then change the gear after measuring its value to get a more accurate value. If the voltage value to be measured is far beyond the maximum range that the multimeter can measure, it should be equipped with another high resistance measuring pen.
