Comparative Statistical Study of the Cornwall, LKB, and Micromedic Dispensers

The working precisions of the 5.0-ml-capacity Cornwall, the LKB 2075, and the Micromedic model 25000 dispensers were compared, and the bias of the LKB dispenser was contrasted with that of the Micromedic dispenser. Three technologists used six Cornwall dispensers, three LKB units with four different pumps, and three Micromedic units with six different pumps to dispense (in 1.0-ml amounts) sucrose solution adjusted to match the normal viscosity of serum. Under these conditions, the LKB dispenser was approximately 30% more precise than the Micromedic dispenser, which was approximately four times as precise as the Cornwall dispenser. Although the left pump site of the Micromedic was slightly more precise than the LKB, overall the Micromedic was less precise than the LKB. Moreover, the LKB was easier to use than the Micromedic.