Thermo液相色谱U3000脱气机真空泵
SYSTEC® ZHCR VACUUM PUMP Introducing the ZHCR® (Zero Hysteresis Constant Run) stepper motor driven vacuum pump, designed and developed for membrane degassing of HPLC mobile phase and other fluids used in Analytical Instrumentation. Employing a micro-stepping closed loop vacuum control strategy permits the pump to maintain a constant vacuum level set-point* by varying the RPM of the stepper motor. The pump initially runs at a high speed which provides for a quick pull down and, as it approaches the vacuum control point, the RPM is gradually reduced until the desired vacuum level is reached. This patented control strategy allows the On-Line Degasser to maintain a virtually constant vacuum that is unaffected by varying degassing loads. As a consequence, fluctuations in baseline due to vacuum hysteresis are eliminated by not having the pump repeatedly stop and start as is done in many older and existing systemsThermo U3000液相色谱仪脱气机真空泵,货号:6040.1981