Since 1994, Measurements International’s (MI) 6010B, and 6010C technology has set the standard for DC Current Comparator (DCC) Resistance Bridge performance in calibration laboratories globally. The time has now come to advance this best-in-class series, taking advantage of twenty-first century AccuBridge® technology.
Measurements International’s major technological advantage in resistance measurements is the development of the only commercially available portable quantum Hall system, QUANTΩ, (Figure 1) which uses AccuBridge® technology as the measurement system operated in ambient temperatures. The current range is from 1 µA to 200 mA for use as a quantum Hall bridge and a resistance bridge . The 6020Q features increased ampere turn (AT) sensitivity with more turns on both the master and slave windings, and a new voltage feedback circuit to improve on the linearity error of the nanovolt amplifier.
Measurements International has world class expertise in both DC Resistance Metrology at NMI’s and ISO17025 Accreditation throughout industry. As your accreditation partner and global support partner, MIL offers leading product knowledge and applications expertise through coaching, system design, implementation, calibration services and ongoing expert support insuring your competitive advantage.
At MI, it’s not only about the equipment and science, it’s about what you can do and the ease with which you can do it.
The AccuBridge® 6020Q (Furthermore 6020Q) room temperature quantum hall resistance bridge can be used to characterize both GaAs/AlGaAs (Figure 2) or graphene samples by measuring and plotting the field sweep, the contact resistance (Vcr), the longitudal resistance and disspation of the I = 2 plateau (Vxx), and transfering the Hall Resistance (Vxy) to a 1,000 Ω or 10 kΩ standard resistor.
Enhancements using AccuBridge® technology include a higher ampere turn sensitivity covering a wider range of resistance ratio, a current and voltage feedback circuit for increased linearity performance and a new calibration technique with increased resolution in obtaining even tighter specifications. In addition to the updated technology, it has the 6010’s dependability, simplified calibration, ease-of-use, automation, speed of measurement and worldwide support making the 6020Q the best and only resistance bridge that offers uncertainty specifications that rival anything available today.
The 6020Q is a fully automated bridge. Its speed, precision and measurement accuracy accounts for its preferred status as the primary resistance bridge in most NMIs throughout the world. It is designed for flexibility and ease of use and is perfectly suited for stand-alone resistor calibrations.
The 6020Q has two inputs: Rx and Rs. The number of inputs can be expanded to 40 when used in conjunction with the 4200 Series Low Thermal Four Terminal Matrix Scanners, see Figure 3. It is recommended that the Model 4210A 10 Channel Matrix Scanner be ordered for use in the quantum Hall system. Measurements can then be performed automatically with software. Delayed or scheduled measurements can be performed at any time.
Automatic current reversal insures that dc offsets and thermals are cancelled outing the measurement. See the 4200 Data Sheet for a complete range of Matrix Scanners.
Overview
As a stand-alone device, the 6020Q is capable of performing the sweep check, contact resistance, longitudinal potential difference (dissipation) and Hall resistance measurements on the quantum Hall resistance (QHR) sample. You can select menu driven functions using the front panel display or over GPIB488. In addition, you can use the 6020Q as a high accuracy dc resistance ratio bridge for calibrating resistors using either a 1 Ω or 10 kΩ standard resistor. For laboratories without a QHR system, the 6020Q can be used to build up from the 1 Ω or down from the 10 kΩ.
The 6020Q performs the field sweep check measurement (see Figure 4) by feeding a current, into the source and drain of the sample, and then reversing it. This enables measurement of potential differences between various points on the sample. These potential differences can be measured at Hall resistances Vxy(1-2) or Vxy(3-4) and the longitudinal resistance Vxx(1-3) and Vxx(2-4) on the sample. Vxy(1-2) and Vxy(3-4) should be in close agreement with each other, as should Vxx(1-3) and Vxx(2-4).
