Patent ID: 7750621

Claim:
A clamp meter adapted for measuring consumption of current and power of an electrical appliance, the clamp meter comprising a power inlet port and a power outlet port and a current detection element arranged between the power inlet port and the power outlet port, a display device mounted on the clamp meter, the power inlet port being adapted to connected to a power source and the power outlet port being adapted to connect to the electrical appliance, whereby when the electrical appliance is turned on, the current detection element detects and converts current flowing through the power outlet port into a digital signal, which is displayed on the displayed device, wherein the clamp meter forms a slide groove outside the power inlet port to slidably receive a gate board, the gate board having edges forming at least one positioning projection, which selectively and sequentially engages a plurality of notches defined in side walls of the slide groove, so as to selectively position the gate board with respect to the slide groove.