When using a multimeter to measure resistance, where should the black-tipped pin be inserted?
The multimeter head is a sensitive magneto electric DC ammeter (microampere meter). When using a multimeter for measurement, first adjust the gear and range, then insert the red probe into the corresponding socket and the black probe into the common terminal socket.
When measuring resistance with a multimeter, set the gear to "Ω", select the appropriate range, and the meter head will be connected in parallel and series with appropriate resistors. At the same time, a battery will be connected in series to allow current to pass through the measured resistor. Based on the magnitude of the current, the resistance value can be measured. When measuring, there is no polarity difference between "+" and "-" for resistance. When measuring polarized components such as crystal diodes and electrolytic capacitors, attention must be paid to the polarity of the probes.
Using a multimeter to measure AC voltage, although the meter head is a magneto electric DC ammeter, when adjusting the gear to "AC~" to measure AC voltage, a parallel or series half wave rectifier circuit is installed. The AC is rectified into DC and then passes through the meter head, so that the AC voltage can be measured by the magnitude of the DC current. So, when measuring AC voltage, as long as the appropriate range is selected, there are no taboos for the red and black probes.
When measuring DC current and DC voltage with a pointer multimeter, pay attention to the polarity of "+" and "-". If the pointer is found to be reversed, the probe should be replaced immediately to avoid damaging the pointer and header. However, when measuring DC current and DC voltage with a digital multimeter, if the polarity is reversed, it is not a big problem, only the display screen shows negative values.
The standard practice is to insert the red probe into the V/Ω hole and the black probe into the common terminal COM hole, so that both voltage and resistance can be measured
In fact, if it is a digital multimeter, you can still measure it by reversing it. The resistance has no polarity, and if the voltage is reversed, it will only display a negative value.
If it is an analog meter, the resistance can also be reversed by inserting the probe, but be careful when measuring DC voltage, as the probe may burn out the meter head anyway
