OptiTemp TT51 series temperature transmitters feature accuracy of 0.05% of span and a five-year stability of 0.05%. The TT51 series is also IEC61508-2 SIL 2-approved for safety-related applications. They work in an ambient temperature range of -40-85 °C, and have a galvanic isolation of 1,500 Vac. They feature a two-, three- and four-wire connection technology.