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Quantum Hall Resistance Bridge

Quantum Hall 6640Q Resistance Bridge, uncertainty +/- 0.015 ppm

RESISTANCE Guildline Instruments


  • Patented Torroid design
  • Dedicated high speed real-time processor for fast measurements
  • Built-in Windows 10 computer and touch screen display providing complete measurement results and graphs
  • Best Accuracy: ± 0.015 ppm of reading at QHR currents of 30 µA - 100 µA with interchange
  • Change all key parameters “On-the-Fly” while the measurement is running


  • The 6640Q QUANTUM HALL RESISTANCE (QHR) BRIDGE has been completely redesigned to provide better uncertainties and more operational capability. The 6640Q Quantum Bridge incorporates many patented new design and measurement technologies to provide a Precision Resistance Bridge operating at room temperature that will scale from the Quantum Hall resistance value of 12906.4035 Ω to nominal resistance values of 0.1 Ω to 100 kΩ.


National Measurement Institutes, Military, and calibration laboratories throughout the world.


More info on the RESISTANCE

The 6640Q is based on over 50 Years of Guildline’s experience designing and manufacturing DCC Bridges; and incorporates customer feedback from over two hundred Guildline 6622A Resistance Bridges in use at NMIs, militaries, and calibration laboratories throughout the world.

In fact, many of the design concepts incorporated into this new 6640Q Bridge are patent protected. While the design enhancements are not visible, the end measurement results are clearly visible. These enhancements allow for considerably less noise, faster measurement cycles, improved stability and repeatability; and most of all, the world's most advanced operator interface found on any Resistance Bridge.

The 6640Q Bridge can be used to build up or down from the Quantum Hall value of 12906.4035 Ω to nominal resistance values from 0.1 Ω to 100 kΩ; transferring directly to 1 kΩ and 10 kΩ with a relative accuracy of 2×10-8 (2 sigma level) or better at the 30 µA to 100 µA level required for QHR Systems. The 6640Q Quantum Bridge can be used stand-alone, with Guildline’s Bridgeworks software, or with its advanced IEEE-488.2 Structure and Industry Standard SCPI Command Set. Guildline’s 6664C Low Thermal Quad Matrix Scanner is also available to automate this process and a customer can easily use their own software to make automated measurements.

For full details download the datasheet

Where we add value

We are measurement system architects

We aim to exceed your expectations and provide solutions which add value to your business and make you more profitable. Our approach is simple yet effective; working with you to ensure that our solutions meet your requirements, perfectly.

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Or speak to our expert UK-based team now

UK +44 (0)1264 316470   US: +1 512 210 2288