Guildline Instruments 6640Q Quantum Hall Resistance DCC Bridge has been designed to provide better uncertainties and more operational capability in Direct Current Comparator (DCC) Resistance Bridges used with Quantum Hall Resistance Systems (i.e. QHRs).


  • New Patented Torroid Design!
  • New High Speed Real-Time Processor For Faster Measurements!
  • New Built-in Windows 10 Computer and Touch Screen Display Providing Complete Measurement Results!
  • Best Accuracy: ± 0.015 ppm of Reading at QHR currents of 30 µA - 100 µA with Interchange!
  • Fasted Measurement Speed of 0.5 Seconds!
  • Change All Key parameters “On-the-Fly” While the Measurement is Running!
  • Linearity: ± 0.005 ppm of Full Scale and Resolution: ± 0.0001 ppm of Full Scale!
  • USB, IEEE 488.2 and Industry Standard SCPI Programming Command Language!
  • BridgeWorksTM Data Acquisition Software and Unique Calibration Support Strategy!
  • Complete Automated Measurement and Turn-Key Systems Available!