Multimeter Measurement of AC Voltage with DC and AC/DC Current
How to measure AC and DC with a multimeter
Digital multimeter to measure AC voltage: the black pen to - or ground (pen jack marked with), the red pen to AC (or V letters under the addition of a ~) holes; gear refers to the AC ~ column of 750 (or 1000) (if it is the measurement of the utility 220V) range. Then the two pens were in contact with the two holes of the power socket, the reading is the value of the AC voltage.
Pointer meter to measure AC voltage: the black pen connected to the negative or ground, the red pen connected to +, gear dial to AC ~ 500V, the same digital multimeter inserted into the two-pen test, the pointer pointed to the number of the right side of the maximum range to correspond to the read: that is, the selection of the 500V file, the readings should be read to see the reading plate on the right side of the maximum number of markers for the 50 row, if the pointer is pointed to 20, then the reading is 200V.
Digital multimeter DC voltage: the same measurement of AC, only the red pen connected to the + hole, the red pen is also in contact with the power supply + pole, gear in the DC (or V letters under a short horizontal line) gear, range depending on the specific circumstances, from large to small. For example, measuring a No. 5 battery, then choose 2V range. If the polarity is reversed, there will be a - negative display before the reading.
Pointer multimeter DC voltage: the same as the digital multimeter measurement method, readings with the above measurements of AC voltage; when you can not determine the positive and negative poles of DC voltage, you can first take it as an AC power to measure, but do not care about the readings, just the pen on the polarity of the measurement to see which of the two measurements of the pointer to be deflected, then this time the pen in contact with that is the correct positive and negative polarity. Then dial the gear to the appropriate range of DC voltage and then measure the reading.
Digital multimeter due to accurate measurement, take the value of convenient, full-featured and other advantages, so by the radio enthusiasts welcome, the most common digital multimeter generally have resistance measurement, sound detection, diode positive conduction voltage measurement. AC and DC voltage and current measurement, transistor amplification and performance measurement. Some digital multimeter is increased capacitance measurement, frequency measurement, temperature measurement, data memory and voice reporting and other functions, to bring great convenience to the actual test work. However, the digital multimeter due to improper use, in the actual detection is easy to cause damage to the table components, resulting in failure. I cause damage to the digital multimeter according to the actual situation, summed up the digital multimeter in the use of the precautions for beginners to try to prevent damage to the digital multimeter.
Digital multimeter damage in most cases is caused by the measurement of the wrong gear, 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 measuring 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, will not cause damage to the digital multimeter.
