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Overview
The AltoNovus ΩhmRanger-LCV (OR-01) is a handheld, low-compliance-voltage ohmmeter designed to measure resistance safely on sensitive devices such as Josephson junctions, nanowires and MEMS. It applies a selectable maximum stimulus of approx. 206 mV or 380 mV and limits current to ~30 mA to avoid forward-biasing or damaging delicate structures. Readings span 10 Ω to >100 MΩ.
A backlit 128×64 display shows resistance, applied voltage and measured current, plus a Signal-to-Noise Ratio (SNR) indicator with min/max current samples. Readings update about every 400 ms and are built from 160 averaged samples to reduce 50/60 Hz hum. A fully isolated micro-USB port supports SCPI control and data export. Power is via two AA cells for around 150 hours, with auto power-off and adjustable backlight to extend battery life.
Why consider ΩhmRanger-LCV?
Where conventional DMMs may apply 3–10 V across a DUT, ΩhmRanger-LCV’s low-stimulus approach helps protect fragile junctions and cryogenic devices while providing practical, portable measurements. It is a focused alternative to using a benchtop SMU when you need quick, safe resistance checks without complex setup.
Related Products
- Resistance Meter Catalogue
- AltoNovus NanoRanger™ NR-01 Nanoammeter (companion DC current instrument)
- AltoNovus brand overview
Why Engineers Choose The AltoNovus ΩhmRanger-LCV (TT-OR-01) Low-Compliance Voltage Ohmmeter
Protect Delicate Junctions
Automate & Log Safely
Faster Stable Readings
Features*
Low stimulus voltages, selectable between approx 380mV or approx 205mV.
- Stimulus voltage at the output terminal is limited by the maximum current supply of approx 20mA.
- Accurate readings from >100M to 10 Ohms.
- A 128 x 64 LCD display gives a wealth of information about your Resistance readings.
- A large display shows MΩ, KΩ, and Ω, all on one line.
- Readings every 400mS, built up from 160 samples and averaged to tune out mains noise (both 50 Hz and 60 Hz).
- Fully isolated USB Interface for device control and readings export.
- SNR display indicates noise level on signal.
- On-screen confirmation of stimulus voltage.
- Range Bar movement after every reading shows that ΩhmRanger-LCV™ is operating correctly.
- Range Coverage Bar shows the ranges covered during the measurement.
- User-configurable Auto Power-off timer.
- ΩhmRanger-LCV™ is highly portable with dimensions of 148 x 90 x 30mm.
- 2 x AA batteries should give around 150 hours of operation.
* Features may be subject to change.
A Real Customer Need - Met
The Josephson Junction is the Quantum Computer's equivalent of a 'transistor'. Although it is delicate, the ΩhmRanger-LCV™ can measure its resistance without risking its integrity.
D-Wave Systems, the Quantum Computing systems and services company, needs to measure the resistance of their Josephson Junctions. Working closely, a prototype Low Compliance Voltage Ohmmeter was quickly developed and the design was subsequently refined through testing and practical lab use. The result is the ΩhmRanger-LCV™, the low compliance voltage ohmmeter, scheduled for general release in October 2021.
On completion of test and evaluation, D-Wave commented;
"The AltoNovus ΩhmRanger-LCV turned an error-prone measurement into a simple measurement ..... a valuable addition to our work building quantum computers."
"The fundamental element in D-Wave's unique product is a Josephson Junction - this is the "transistor" in a quantum computer. In practice, these devices are extremely sensitive and easy to damage. Measuring the resistance with a standard multimeter will destroy the Josephson Junction.
The AltoNovus ΩhmRangerLCV turned an error-prone measurement into a simple measurement. The low compliance voltage ensures that the device under test never sees a stimulus above 400mV. The ΩhmRanger-LCV measures a wide resistance range, and the upper end of the range (400MOhm) ΩhmRanger-LCV makes it simple. This, in addition to a nice group of features, including a quality metric - signal-to-noise, continual indication of the stimulus voltage, and a cute mode for measuring microscopic pins while looking through a microscope, makes this device a valuable addition to our work building quantum computers."
General Information | |
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Part Number (SKU) |
TT-OR-01
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Manufacturer |
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Physical and Mechanical | |
Weight |
0.3 kg
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Other | |
Warranty |
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HS Code Customs Tariff code
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EAN |
5055383620371
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Frequently Asked Questions
Have a Question?
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Is ΩhmRanger-LCV certified for lab use?
Yes. The manual lists UKCA, CE and FCC compliance; operating environment is 0–50 °C, 10–90% RH non-condensing.
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Does the USB isolation help measurement accuracy?
Isolation reduces ground loops and PC-coupled interference that would otherwise corrupt low-level measurements—important when measuring nanoamps across high resistances.
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Is this a replacement for an SMU (e.g., Keysight B2900, Keithley 2400)?
No. SMUs source/measure with flexible sweeps but are larger and costlier. ΩhmRanger-LCV is a focused, portable low-stimulus ohmmeter for safe resistance checks.
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How long does the instrument run on batteries?
Typical operation exceeds 150 hours on two AA cells, helped by an auto power-off timer and backlight control.
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Can I automate measurements or log data to a PC?
Yes. A fully isolated micro-USB port supports SCPI commands for control and data export into scripts or logging tools.
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What is the SNR readout for?
It quantifies noise on the signal and shows minimum/maximum current during a reading, helping diagnose pickup and optimise fixturing and shielding.
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How fast are readings and how is noise handled?
Displays update about every 400 ms and average 160 samples to reduce 50/60 Hz mains hum for stable results.
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What resistance range does it cover?
From 10 Ω to greater than 100 MΩ, suitable for contacts, thin films, sensors and wiring.
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Why use ΩhmRanger-LCV for Josephson junctions or cryogenic devices?
Such devices can be damaged by higher stimulus voltages; ΩhmRanger-LCV’s low-stimulus design enables resistance checks without exceeding ~400 mV.
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What does “low compliance voltage” mean on ΩhmRanger-LCV?
It limits the maximum voltage applied to the DUT (206 mV or 380 mV), reducing risk of junction damage compared with multimeters that apply several volts.