The Kele T81U Platinum RTD Rangeable Transmitter is a two-wire, 4-20 mA transmitter designed for use with Type 81 100Ω platinum RTD sensors. The transmitter is available in three standard ranges, or it can be set for any range between -30° to 250℉ (-34° to 121℃) with a minimum span of 40℉ (22℃). To adjust the T81U, set the DIP switches to match the desired range and use the zero and span pots to fine tune. A high accuracy digital ohmmeter and decade box are required. The T81U has a special 20 mA loop calibration test signal to provide easy system verification. Simply move the bottle plug jumper from NORM to 20, and the transmitter will output a constant 20 mA. The Loop Up LED provides power indication for the 4-20 mA output.