GUILDLINE INSTRUMENTS 6640Q QUANTUM HALL RESISTANCE (QHR) BRIDGE has been completely redesigned to provide better uncertainties and more operational capability.


  • New Patented Toroid Design
  • New Dual Processor Design
  • New Dedicated High Speed Real-Time Processor For Fast Measurements
  • New 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
  • Fasted Measurement Speed of 2 Seconds
  • Change All Key parameters “On-the-Fly” While the Measurement is Running
  • Linearity: ± 0.005 ppm of Full Scale
  • Resolution: ± 0.0001 ppm of Full Scale
  • Fully Programmable USB, IEEE 488.2
  • Industry Standard SCPI Programming Command Language
  • BridgeWorksTM Data Acquisition Software
  • Unique Calibration Support Strategy
  • Complete Automated Measurements
  • Quantum Hall Turn-Key Systems Available