Technel represents Guildline Instruments who have produced the world’s best known thermometry bridges for 50 years and counting. The Model 6622T is the thermometry version of the 6622 series of the Direct Current Comparator family of electrical resistance bridges offering leading uncertainties and stabilities for temperature bridges. This design introduces unique innovations in hardware and software for a wide range thermometry bridge accommodating SPRT’s, PRT’s, various RTD’s, and thermistors. The measurement range of the 6622T Series is from 0.1 Ω to 100 kΩ and the XP version of the 6622T has a best uncertainty of 0.05 ppm. The newest Guildline product in thermometry bridges is the 6640T, a completely redesigned DCC temperature bridge providing better uncertainties, faster measurement rates and more operational capability. The 6640T best measurement accuracy is provided by the XP model (eXtended Performance) which boasts 0.015 ppm at 1 mA operating current over the entire SPRT range with a full 10 1/2 digits display resolution.