Profile: Sierra Control Systems, Inc. is a manufacturer of water measurement products. Our products include remote terminal units, pump controller, tank level monitor, gate controller, remote level monitor, valve controller, water level transducer, well depth monitor, remote telemetry unit, battery/solar powered gate control system, line protector and battery chargers. Our series 900 RTU pump controller is designed to control one or more pumps to keep a local or remote storage tank full or to control the system pressure.