Model TZ is certified by exida to IEC61508 for systematic integrity up to SIL 3, and for single use in safety instrumented systems (SIS) up to SIL 2. The functional safety, dual-input smart Hart DIN-style temperature transmitter with associated IS sensor connections configures quickly and easily to accept a single or dual input. The intrinsically safe AIS option for the STZ-DIN allows direct connection of sensors located in hazardous locations by including an embedded intrinsically safe barrier in the front end of the STZ-DIN. The associated apparatus is suitable for mounting in nonhazardous or Class I, Division 2/Zone 2 hazardous locations with sensor input terminals connected to sensors or equipment in Class I, II, III, Division 1/Zone 0/1 hazardous locations. Inputs accepted include sensors and analog devices such as RTDs, thermocouples, resistance and potentiometer devices, and direct millivolt inputs.