Engineered for versatility, the Rosemount 644 Temperature Transmitter is available with HART®, FOUNDATION™ Fieldbus or PROFIBUS® protocols in head, field or rail mount styles and a variety of enclosure options. By adding a Local Operator Interface (LOI), you can update your transmitter configuration in the field without tools. For diverse application requirements, this transmitter includes diagnostic capabilities, such as Hot Backup™ capability, sensor drift alert and thermocouple degradation.