1. A computer-based method for measuring volume of a drop, comprising: storing, in a memory element of a computer, computer readable instructions; expelling a first plurality of drops of a first substance from a source element, through a medium, and under at least one condition, wherein a density of the first substance is known; executing, using a processor for the computer, the computer readable instructions to: generate respective images of drops in the first plurality of drops as the drops are passing through the medium; calculate an uncalibrated volume for the first plurality of drops using the respective images of the drops in the first plurality of drops; expelling a second plurality of drops of the first substance from the source element, through the medium, and under the at least one condition; and, executing, using the processor, the computer readable instructions to: calculate, using a weight for the second plurality of drops and the known density, an actual volume for the second plurality of drops; and, generate, using the uncalibrated volume and the actual volume, an equation to modify the uncalibrated volume to match the actual volume, wherein: expelling the first plurality of drops under at least one condition includes exposing the first plurality of drops to a first physical condition affecting the medium: after the first plurality of drops has been expelled from the source element; while the first plurality of drops is passing through the medium; and, before travel of the first plurality of drops through the medium has terminated; expelling the second plurality of drops under the at least one condition includes exposing the first plurality of drops to the first physical condition affecting the medium: after the second plurality of drops has been expelled from the source element; while the second plurality of drops is passing through the medium; and, before travel of the second plurality of drops through the medium has terminated.