Product features: Digital LCD display, easy to read, can display measurement data and graphics Rotary switch control, easy to use for key measurement Press and hold the test button to exit the frequency measurement function. The frequency measurement range is from 1Hz to above 1MHz. When the measured frequency is lower than 25KHz, the cycle is displayed Square wave generator, with multi gear square wave frequency selectable. Rotate the left or right test button to switch to different square wave frequencies, and long press the test button to exit the square wave generator Pulse signal generator, turn left or right test button to adjust the pulse duty cycle from 1% to 99%. Press and hold the test button to exit the pulse signal generator Use 5V Type-c power supply interface for power supply, and customers can also weld 9V battery interface for power supply Automatic shutdown, shutdown current is only about 20nA Note: Before testing the capacitor, first discharge the capacitor, and then insert it into the test base for measurement, otherwise the microcontroller of the tester may be damaged. Input voltage: DC5V Working voltage: about 30mA, Control of transistor tester The tester is controlled by a rotary encoder switch, The rotary encoder switch can be operated in 6 ways: short press, long press, left rotation, right rotation, press and hold left rotation, press and hold right rotation. Press once in the shutdown state to turn on the power and start the test. If no device is detected after one test. Press and hold the switch or rotate the switch left and right to enter the function menu. After entering the function menu, the left or right switch can be selected above or below the menu item. To enter a function item, press the switch briefly. When you need to exit from a function, press and hold the switch. Calibration: The tester calibration is used to eliminate the error of its own components and make the final test results more accurate. Calibration is divided into quick calibration and full function calibration. Operation method for quick calibration: short circuit the three test points TP1, TP2 and TP3 with wires, then press the test button, and observe the screen at the same time. The screen color will become white on a black background, and the prompt message "Selftest mode..?" will appear After that, press the test button to enter the fast calibration process; If the prompt "Self test mode..?" appears After that, if no key is pressed within 2 seconds, a normal test process will be conducted, and the resistance values of the wires shorting TP1, TP2, and TP3 test points will be displayed finally. After entering the quick calibration process, some data will appear on the screen, regardless. Wait until a flashing string appears on the screen isolate Probes! After that, remove the wires shorting TP1, TP2 and TP3. The quick calibration is completed until the string "Test End" appears on the screen. For the first calibration, use the full function calibration mode. Full function calibration needs to be entered from the function menu, and another 220nf capacitor needs to be prepared. Full function calibration performs a more comprehensive calibration process and takes longer. After entering the function menu, turn the test button to the menu item "Selftest", and then press the test button to enter the full function calibration process. The flashing string "short Probes!" first appears on the screen, At this time, just like rapid calibration, use wires to short circuit the three test points and wait for the calibration process. The flashing string "isolate probes!" appears on the screen When the string "1 - | | - 3>100nf" appears on the screen, the prepared 220nf capacitor is installed on test points TP1 and TP3. Wait until the screen prompts "Test End", and the full function calibration process is completed. Package list: GM328A transistor tester X1