The Kele ST-T91D Rangeable Wall Delta style Temperature Transmitter Series provides stable, accurate room sensing for temperature control and building automation systems, and it is CE approved for level-one applications. The ST-T91D Series has a loop-powered 4-20 mA output with a standard temperature range of 40° to 90°F (4° to 32°C), although other ranges can be field calibrated between -30° to 250°F (-34° to 121°C). To adjust the ST-T91D Series, 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 ST-T91D Series 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.