Digital Voltmeter Intelligent,High speed,High accuracy,High impedance,Auto,wide range,high reliability, With LCD screen ,RS-232 Digital Millivoltmeter: ... ,RS-232 availabl DF1934ADF1935 DF1934BDF1935B Range100μV~300V-80dB~50dB-77dBm52dBm100μV~300V-80dB~50dB-77dBm52dBm Error1.5%1 ... ~2MHz Input impedance10MΩ//30pF10MΩ//30pF ModeOne CH V,dB/dBmDual CH V,dB/dBm IndicationDigital,Model B with RS232Large ...