Technel represents Guildline Instruments one of the world’s premier manufacturers of resistance metrology instrumentation. Guildline produces standard resistors of different accuracy levels to meet any resistance measurement application from bench top instrumentation to the most demanding national metrology laboratories. Products include 4-terminal decade box standards and RTD simulators, precision air and oil based resistors and ultra high-value resistance standards up to 10 Peta ohms. Guildline also manufactures precision air and liquid baths to alleviate temperature effects on resistance measurements providing the best possible environmental control and reduced uncertainty. The latest product for the ultimate in resistance measurement is the Model 6625A-QHR, a complete quantum Hall resistance turn-key system which includes a Quantum Hall semiconducting device maintained at 1.5 Kelvin with a He-4 refrigerator within a high magnetic field produced by a superconducting magnet. Under these conditions the Quantum Hall plateaus of resistance are easily obtained providing turn-key measurements of resistance devices at any point within the measurement range of 10 mΩ to 100 kΩ.