Multimeters, also known as multiplex tables, multimeters, tri-meters, and multi-use meters, are indispensable measuring instruments for power electronics and other departments. Generally, voltage, current and resistance are the main purposes. The multimeter is divided into a pointer multimeter and a digital multimeter according to the display mode. It is a multi-functional, multi-range measuring instrument. The general 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 semiconductor. Some parameters (such as β) and so on.
The multimeter can be used not only to measure the resistance of the object being measured, but also to measure the DC voltage. Even some multimeters can measure the main parameters of the transistor and the capacitance of the capacitor. Fully mastering the use of the multimeter is one of the most basic skills of electronic technology. Common multimeters have pointer multimeters and digital multimeters. The pointer multimeter is a multi-function measuring instrument with a head as the core component, and the measured value is read by the head pointer. The measured value of the digital multimeter is displayed directly by the liquid crystal display in digital form, which is convenient to read, and some also have a voice prompt function. The multimeter is a meter that shares a meter head, a voltmeter, an ammeter, and an ohmmeter.
It is not suitable for the multimeter to measure the leakage of 220V. Because you want to measure the leakage current, the multimeter's measurement of weak AC current is a weak item. It is also troublesome to measure. If you have to measure it, you need to use a current transformer. You might as well Use a clamp meter to measure, but use a clamp meter with a suitable range and better sensitivity.
If you suspect that the circuit is leaking, you can use the empty open with leakage protection to judge the range of leakage and solve the fault.
As for the use of electricity to block the leakage of the measurement line, I feel that it is not suitable. Because it is leakage, the resistance between the hot wire and the protective ground is not infinite, but the voltage of the multimeter is not enough to explain the insulation between them, that is to say, the insulation resistance is completely different when the voltage is 9V and 220V. Therefore, the measured insulation resistance is measured at a higher voltage than the applied voltage to obtain reliable data. So you must use a shaker.
Of course, if you only measure the short circuit or path between the fire line and the protection ground, it is also possible to use a multimeter to block the electricity. It is just impossible to measure the insulation data between them.
Strictly speaking, the measurement of the line insulation resistance circuit should use a shaker. The shaker is equivalent to a 1000v or 500v generator. The leakage current is generated by the sampling resistor inside the table and the sampling voltage is generated on the resistor. Normally, a stability greater than 0.5 mega ohms is acceptable. The internal battery of the multimeter is 9v to 15v. The resistance and voltage files can only determine the short circuit, and roughly judge whether there is leakage.
1. Power-off measurement: Turn off all electrical appliances, use the multimeter RX10K file, one test pen to receive the test fire line, and the other test pen ground (or faucet), it should show the resistance infinity, otherwise leakage.
2. Live measurement: use the multimeter 250V AC voltage file to measure the metal casing of the electrical appliance suspected of leakage. One meter is connected to the outer casing, and the other is grounded (or faucet). When the voltage is higher than 30-50 volts, the indicator is changed. Use AC 50 volts, if the power supply is confirmed to be higher than 30 volts, it is normal, less than 30 volts is normal, and then the zero and fire power plugs are reversed and measured once to determine.
3. Leakage measurement between the live wire and the neutral wire (or fire wire and fire wire): Turn off all electrical appliances and measure the resistance between the live wire and the neutral wire. It should be infinite, otherwise it is leakage.
The accuracy of the above method for troubleshooting is 99.9%, which is convenient, rapid and practical. The megohmmeter special shaker must be used only when doing engineering. The efficiency of maintenance is low. Only the multimeter measurement is confirmed, but the line is indeed leaking. Shake the watch, but the multimeter can't measure the leakage.
In addition, the calculation of the household electrical equipment, the length of time, for 4 & TImes; 6 square line, if the power equipment, long-term use, about 200 degrees a month is not much, if far greater than this number, you can judge the home has leakage Happening.
Tws Sports Headphones,Wireless Sport Earphone,Sports Bluetooth Earphones,Wireless Earphones For Workout
Guangzhou YISON Electron Technology Co., Limited , https://www.yisonearphone.com