UT804 is a 40000 count 4 3/4-digit, auto-ranging true RMS desktop digital multimeter. It features a full-function analog bar graph display, full-range overload protection, and dual power supply mode (battery and AC power), making it a high-precision electrical measurement instrument with superior performance. This meter can be used to measure: true RMS AC or (AC+DC) voltage and current, DC voltage and current, resistance, diode, circuit continuity, capacitance, frequency, duty cycle, temperature, (4~20mA)% measurement, maximum/minimum value, relative measurement, etc. It also has white backlight, user settings, RS232 and USB data transfer, 9999 data storage, data hold, low battery indication and auto power off function when powered by battery.