Mar 18, 2022 
Saelig Company, Inc has introduced the AltoNovus OR-01 OhmRanger-LCV™ Low Compliance Voltage Ohmmeter, an accurate, affordable, portable meter which can measure a wide range of resistances simply and quickly. Individually factory-calibrated, this meter measures resistances from greater than 100Mohms down to 10 Ohms. Additional built-in features include a signal-to-noise measurement, which indicates how much noise, variation, and AC elements are in the signal, as well as maximum and minimum current samples during the reading. Higher resistances (lower currents) are more susceptible to noise errors.
The maximum regulated stimulus voltage that can be supplied by OhmRanger-LCV can be selected as 206mV or 380 mV to prevent harming a device under test. The maximum stimulus current is limited to approximately 30mA. A backlit 128 x 64 LCD display provides a wealth of information about the resistance readings, which are displayed every 400mS and built from 160 averaged samples to eliminate 50/60 Hz line noise. Factory set calibration compensation is applied to both current and voltage, in order to give an accurate reading of resistance. A configurable audible signal informs the operator that a stable reading has been achieved.
A typical application example is that of D-Wave Systems, a quantum computing systems and services company that needed to measure the resistance of their sensitive Josephson junctions (a Quantum Computer's equivalent of a 'transistor'). In practice, these devices are extremely sensitive and easy to damage. Most conventional ohmmeters are designed to apply a 3-10V stimulus voltage to the Device Under Test (DUT). Measuring the resistance of a Josephson junction with a standard multimeter will destroy the device. D-Wave staff noted: "The AltoNovus OhmRanger-LCV turned an error-prone measurement into a simple measurement, a valuable addition to our work of building quantum computers. The low compliance voltage ensured that our device under test never sees a stimulus above 400mV.”
A fully-isolated micro-USB interface is provided in the OhmRanger-LCV for device control (SCPI-format) and data export, essential in preventing a PC connection cable from affecting sensitive measurements. The compact (5.8” x 3.6” x 1.2”) and lightweight (7oz) OhmRanger-LCV is powered by 2 x AA batteries, which provide about 150 hours of operation. A user-configurable automatic Power Off timer and configurable LED backlight helps to maximize battery life.
The OhmRanger-LCV is designed by UK-based AltoNovus, which specializes in designing and building compact, low power measurement products. Aimed at the quantum computing and nanostructures communities, including those focused on Transition Edge Sensors, nanowires, nanoscale meta materials, and Micro-Electro-Mechanical technologies.
