The stepper motor driven Systec vacuum pumps were specifically designed and developed for membrane degassing of HPLC mobile phase. Employing a closed-loop micro-stepping RPM control strategy permits the pump to run with continuously variable speed, to provide quick pull-down at high RPM, then sustain a consistent vacuum level at low RPM.
Fluctuations in baseline due to vacuum hysteresis are eliminated by not having to repeatedly stop and start a single-speed pump. This also greatly reduces wear and noise. The low wattage DC stepper motor runs quietly and coolly, and is very adaptable in its power supply requirements. The brush-less motor is especially appropriate for an environment where solvent vapors may be present.
The need for a vent valve has been eliminated by the continuously purged head design and built-in anti-backflow duckbill check valves. The pump will start into a full vacuum and vacuum will not be released in the event of a power loss. The entire pump assembly is compact in design.
