... ,High impedance,Auto,wide range,high reliability, With LCD screen ,RS-232 Digital Millivoltmeter:Intelligent High speed,High accuracy,High impedanceAuto ... ,wide range,high reliabilityWith LCD screen ,RS-232 availabl DF1934ADF1935 DF1934BDF1935B Range100μV~300V-80dB~50dB-77dBm52dBm100 ...