A syringe-based, electronic fluid dispenser is described. The device mechanically connects a syringe plunger to a linear slide potentiometer. As the syringe plunger moves, the electrical resistance between terminals of the potentiometer varies. Application and subsequent measurement of a DC voltage between the potentiometer pins is used to track the syringe plunger position and meter the volume dispensed. The syringe’s plunger is actuated manually by the device’s user. The dispensing device offers volumetric accuracy of better than 1% when the dispensed volumes were >10 mL. The device has been used for a traditional acid–base titration experiment and produced quantitative results indistinguishable from the conventional approach using a buret. The device is inexpensive, easy for students to understand, and simple to construct.
|Pages (from-to)||pp 106–109|
|Journal||J. Chem. Education|
|State||Published - Jan 15 2015|