Superaccurate multimeter

Called the PXI-4071 FlexDMM, the device is a modular instrument that plugs into a bus backplane. Developed by National Instruments Inc., it measures voltages from ±10 nV to ±1 kV and resistances from 10 µ to 5 G. A solid-state current shunt measures dc current in eight ranges from 1 µA to 3 A along with 6 ac rms current ranges from 100 µA to 3 A. Reading rates vary from 7 samples/sec at 7-1/2 digits to 10 ksamples/sec at 41/2 digits. The digitizer acquires dc-coupled waveforms in all voltage and current ranges with a 1.8 Msamples/sec maximum sample rate. It incorporates built-in isolation to allow measuring differential waveforms up to 500-V common mode. Time and frequency domain analysis of fly-back signals and other aperiodic highvoltage ac waveforms take place using a graphical development environment called LabView.