1.2. Use the method that the meter pen of the machine contacts the two ends of the wire. If the machine gives a sound and light alarm, it means the wire is conductive; otherwise, it is broken. On the contrary, it is an open circuit. 2.1. This machine is mainly used to drytest the continuity of wires and other conductors, equivalent to a thousandohm multimeter's continuity file, simple and convenient to use. 3.4. This machine uses a 9V battery. You can open the back cover to the battery. The product principle diagram is as follows. The red and black meter pens are equivalent to switches. When not measuring, the circuit is off and there is no current consumption. A 9V battery can be used for 3 5 years. 4.3. Before the test, directly short the meter pens of the machine. If there is a sound and light alarm, it is normal. If not, please check whether the meter pens or the battery is normal.