A Volumetric Delivery or Sampling System for Manual Use or Use with a Time Shared Computer

ABSTRACT A volumetric delivery and/or sampling system using a syringe operated with a stepping motor was developed for manual or time-shared computer controlled applications. The unit has its own clock, logic, indicators, and data storage registers arranged so that a time-shared computer can give the unit instructions, go on to other jobs, and return to service the volumetric system when the unit has completed its assigned task. For each clock-wise or counterclockwise step the motor makes, an up-count or down-count is made in a digital counter that measures the displacement of the syringe plunger. The system can be operated in a continuous mode where the plunger is moved continuously in either direction at one of eight rates until a limit switch is encountered. It can be operated in a step mode where the plunger is moved a distance corresponding to up to 256 motor steps in either direction from the current position. Lastly, it can be operated in a preset mode where the plunger is moved from any position t...