As a result of research conducted by the Department of Materials Science and Metallurgy at the University of Cambridge and tests conducted in the calibration laboratory at CCPI Europe Ltd, a new mineral insulated (MI) thermocouple cable has been developed for sensor manufacturing. The use of both type K and type N base metal thermocouple combinations under operational conditions during extended and/or high temperature conditions have historically been shown to have a limited life operation. The test results on mineral insulated cable show that conventional type K mineral insulated thermocouple designs can maintain calibration limits and stay within IEC 60584 -1: 2013 class 1 and ASTM E230 special tolerances for a limited number of operations. However, when compared to the type K sensors, manufactured from the new designed mineral insulated cable, these new designs have been shown to maintain calibration values to meet both IEC 60584 -1: 2013 class 1 and ASTM E230 special tolerances for up to five times longer. This new mineral insulated cable can allow type K and N thermocouples to work longer and at higher temperatures with significantly reduced drift, offering greater measurement confidence. This paper will discuss how the new design will offer the opportunity for type K and type N MI thermocouples to work for longer and at higher temperatures under both continuous and cycling conditions with significantly reduced drift, giving increased confidence in measurement capability.