A method for calculating a volume and content type of liquid of an individual falling drop of liquid by analyzing electromagnetic radiation (EMR) reception, said method comprising: projecting electromagnetic radiation (EMR) from an EMR source in one or more collimated beams to a restricted horizontal planar area, wherein said collimated beams span an area that exceeds an area of a vertical cross section of a center axis of a drop falling between said EMR source and an EMR sensor when said drop interferes with said EMR ; measuring said EMR using said EMR sensor when said EMR is partially interfered with by said drop ; and using a processor to execute code instructions for: calculating a plurality of widths of said drop along a vertical axis of said drop, each one of said plurality of widths is calculated according to a reception of a time correlated measured portion of said EMR; calculating a volume of said drop by combining said plurality of widths and a velocity of said drop when said drop is falling between said EMR source and said EMR sensor ; detecting, based on said plurality of calculated widths, at least one image of said drop; comparing said at least one image to a respective image of at least one of a plurality of exemplary drops of different content types of liquid; identifying, according to said comparison, one of said different content types as a liquid type of content of said drop; and controlling a flow rate of a liquid delivering device, according to said calculated volume. projecting electromagnetic radiation (EMR) from an EMR source in one or more collimated beams to a restricted horizontal planar area, wherein said collimated beams span an area that exceeds an area of a vertical cross section of a center axis of a drop falling between said EMR source and an EMR sensor when said drop interferes with said EMR ; measuring said EMR using said EMR sensor when said EMR is partially interfered with by said drop ; and using a processor to execute code instructions for: calculating a plurality of widths of said drop along a vertical axis of said drop, each one of said plurality of widths is calculated according to a reception of a time correlated measured portion of said EMR; calculating a volume of said drop by combining said plurality of widths and a velocity of said drop when said drop is falling between said EMR source and said EMR sensor ; detecting, based on said plurality of calculated widths, at least one image of said drop; comparing said at least one image to a respective image of at least one of a plurality of exemplary drops of different content types of liquid; identifying, according to said comparison, one of said different content types as a liquid type of content of said drop; and controlling a flow rate of a liquid delivering device, according to said calculated volume. calculating a plurality of widths of said drop along a vertical axis of said drop, each one of said plurality of widths is calculated according to a reception of a time correlated measured portion of said EMR; calculating a volume of said drop by combining said plurality of widths and a velocity of said drop when said drop is falling between said EMR source and said EMR sensor ; detecting, based on said plurality of calculated widths, at least one image of said drop; comparing said at least one image to a respective image of at least one of a plurality of exemplary drops of different content types of liquid; identifying, according to said comparison, one of said different content types as a liquid type of content of said drop; and controlling a flow rate of a liquid delivering device, according to said calculated volume. <EOS>