Rapid-Tech Equipment was started in 1996 by Mike Collins after many years working in senior management in a number of the world’s leading test equipment companies. He believed there was a need for a company that could provide advice & high quality test & measuring equipment to it’s customers at a substantial cost savings.So, when you are in the market to buy test equipment, Rapid-Tech Equipment is your complete test & measurement equipment resource. This website is designed to provide the most-up-to-date technical information, and it is hoped that you our customer will find out everything you need to know without having to look further.
The Guildline 6645Q Quantum Hall System was developed to meet the needs of Standards Laboratories across the world for improved calibration and maintenance of primary resistance standards.
Based on Guildline’s 60 years of experience in high precision resistance measurements and 50 years of expertise in Direct Current Comparison (DCC) Resistance Bridges, the 6645Q System is the leading calibration system for primary resistance standards.
± 0.005 ppm (1:1to 13.4:1 Ratios)
Display resolution (ppm)
Selectable (Programmable) from 0.0001 ppm to 10 ppm
0.01 ppm/°C of reading (Outside Operating Temperature)
Automatic current reversal rate (in seconds)
4 to 1637 programmable, increment of 1 second
Fastest Measurement Sample Rate
USB, IEEE488.2, SCPI Based Language Instructions
Test current (for measurements to 100 kO)
Range (±30Vdc compliance)
Accuracy[error(ppm) + offset(A)]
Bridge Operating Temperature to Full Specifications
21 °C to 25 °C
69.8 °Fto77 °F
Bridge Maximum Operating Range (<50 % RH)
+ 18 °C to +28 °C
+65 °Fto +82 °F
Bridge Temperature Storage Range
-20 °C to +60 °C
-4°Fto+ 140 °F
Vac:100 V, 120 V, 220 V, 230 V and 240 V; All ± 10 %