How to distinguish between zero wire and fire wire and earth wire with a multimeter
1 method: the multimeter set to the beeping gear with a pen contact zero row, another pen were in contact with several unknown wires - the pen is not long enough? You can take a piece of wire, one end of the wire is connected to the zero row, and the other end is led to the test e69da5e887aae799bee5baa6e79fa5e981933131333365666235 point near. Anything that makes the multimeter beep during the test is the zero wire.
2 Voltage to ground method
Method: Measure several lines to be tested and the wall (there is a known ground or ground row of course, better) between the voltage, the resulting voltage is called "ground voltage". Voltage to ground for 220V or so, is the firewire; to ground voltage is 0, is the ground; to ground voltage is not 0, but still very low (usually not more than 24V), is the zero line.
Multimeter, also known as multipurpose meter, multi-purpose meter, triple meter, complicated meter, etc., is an indispensable measuring instrument for power electronics and other departments, generally to measure voltage, current and resistance as the main purpose. Multimeter is divided into pointer multimeter and digital multimeter according to the display mode. It is a multifunctional, multi-range measuring instrument, generally the multimeter can measure DC current, DC voltage, AC current, AC voltage, resistance and audio level, etc. Some can also measure AC current, capacitance, inductance and some parameters of semiconductors (e.g., β) and so on.
Basic functions
Multimeter can not only be used to measure the resistance of the object being measured.
AC and DC voltage can also be measured DC voltage. Some multimeters can even measure the main parameters of transistors and the capacitance of capacitors. Fully master the use of multimeter is one of the most basic skills of electronic technology. Common multimeters are pointer multimeters and digital multimeters.
Pointer multimeter is a multi-functional measurement instrument with a head as the core component, and the measurement value is read by the pointer of the head. Digital multimeter measurement value by the liquid crystal display directly in the form of digital display, easy to read, some also with voice prompts. Multimeter is a common head, set of voltmeter, ammeter and ohmmeter in one instrument.
Multimeter DC current gear is a multi-range DC voltmeter. Its voltage range can be extended by connecting a closed-circuit voltage divider resistor in parallel with the meter head. The DC voltage range of the multimeter is a multi-range DC voltmeter. The voltage range of the multimeter can be enlarged by connecting a voltage divider resistor in series with the head of the meter. Different voltage divider resistors have different ranges. The multimeter's head is a magneto-electric measurement*, which can only pass DC, and uses a diode to change AC to DC, thus realising the measurement of AC power.
