Spirax Sarco SP400 and SP500 digital positioners consume approximately 1 percent of the air of a traditional electropneumatic positioner. The SP400 model has a simple menu system and can perform an auto-stroke calibration at the press of a single button. The full-featured SP500 positioner includes optional retransmission of valve position; software switches; the ability to use a separate 24 Vdc power supply; and communications protocols as well as diagnostics. 

Spirax Sarco, Inc.; 803-714-2000