The power supply for the pressure transmitter must be made via an energy-limited electric circuit in accordance with section 9.3 of UL/EN/IEC 61010-1 or an LPS per UL/EN/IEC 60950-1 or class 2 in accordance with UL1310/UL1585 (NEC or CEC). The power supply must be suitable for operation above 2,000 m should the pressure transmitter be used at this altitude.