Guildline’s NEW 6645Q Quantum Hall Resistance System has been designed and developed to meet the needs of Standards Laboratories around the world for an improved level of accuracy in the calibration and maintenance of primary resistance standards.


  • Complete Turn-Key QHR System – Fully Integrated and Ready to Use!
  • New 6640Q DCC Bridge With Patented Toroid Design and New Dual Processor Design!
  • Built in Nano-Voltmeter for Hall Resistances and Longitudinal Resistances!
  • Pre-Cool with Nitrogen for Cost Savings!
  • 4 to 6 Day Uninterrupted QHR Operation!
  • Option for Magnetic Field Strength up to 14 Tesla!
  • Best Accuracy: ± 0.015 ppm of Reading at QHR Currents of 30 µA - 100 µA With Interchange!
  • Premium QHR Sample Included, built by NMI with 20 years’ Experience!
  • Fasted Measurement Speed of 0.5 Seconds!
  • BridgeWorks™ Data Acquisition Software and Complete Automated Measurements!