Description Description: In the display interface, click the button to switch the data set;continue to pre the button to clear the accumulated data to zero. Component aging and temperature changes after prolonged use may introduce minor errors in measuring small currents. To avoid this error, you can unplug the current outlet and pre and hold the button to connect the power until the display shows AAAand then release the button. Use isolated power Both power supplies must be isolated and not connected to any load. The maximum voltage of the isolated power supply is 20V Powered by a DC-DC converter Black thin wires are not connected and should be wrapped with insulators to avoid short circuits. The DC-DC converter must be a universal cathode structure. Using system power Black thin wires are not connected and should be wrapped with insulators to avoid short circuits. Note: After a long time use, due to the aging of components or temperature variation, it may appear tiny error when measuring the small current. To avoid this error, you can unplug the current wire socket and keep preing the button to connect power supply until the screen display AAA, then loose button. Package Included: 1 X Multifunction Electrical Parameter Meter Tester