For first time to upgrade the software, please install USB driver as the instruction(how to install usb driver.txt) in folder driver, Please note the PC tools only can be run on PC with OS WinXP or Win7

1. Power off the meter
2. Connect the meter and PC by USB cable.
3. Power on the meter.
4. Run COMBO_DFU.exe
5. Choose the new firmware
6. Click on Start.
7. Power off the meter once download finished.
8. Remove USB cable
9. Power on meter again.
