Digital multimeter detects the principle circuit of bidirectional thyristor

The picture below is a schematic diagram of testing using a digital multimeter. Turn it to the NPN position, first open the G pole of the bidirectional thyristor VT, connect the pole to the "C" hole of the hFE socket through the current limiting resistor R (about 330Ω), and insert the T1 pole into the "E" hole through the wire. The role of the resistor R here is to prevent the hFE line from being overloaded. At this time, the digital multimeter displays "000", indicating that it is in the off state. Then use a wire to short-circuit the G pole and T2. The multimeter number immediately jumps from "578" to "578", which indicates that there is continuity. The picture on the right is a verification circuit for bidirectional conduction of a bidirectional thyristor. The difference from the picture on the left is that the T1T2 is reversed, and the G pole is still touched with the C pole through the wire. At this time, the digital multimeter displays the value from "000" to "428". This proves that the bidirectional thyristor can conduct electricity in both directions. Yes, the quality is good.