A sample adequacy measurement system comprising: a sample tube unit comprising a frame extending horizontally along a longitudinal axis and a plurality of sample tubes (150, 1104) connected to the frame and arranged in a line along the longitudinal axis, each sample tube extending downward in a vertical direction from the frame; a housing (120, 420, 520) having a receptacle formed therein, the receptacle extending in the vertical direction and being dimensioned to selectively receive the plurality of sample tubes therein; a plurality of sample adequacy measurement stations associated with the housing, each sample adequacy measurement station comprising: a light source (102, 202) adapted to selectively generate an illumination beam directed upwards in the vertical direction through the receptacle and into a respective one of the sample tubes; a sample detector (108, 208, 408, 508) positioned along a vertical extent of the respective one of the sample tubes and adapted to receive an emitted beam comprising at least a portion of the illumination beam scattered by turbidity in the respective one of the sample tubes, wherein the sample detector is positioned at the end of an emitted beam channel, and wherein the emitted beam channel (106, 214, 414, 514) extends in a plane that is perpendicular to the vertical direction and is oriented at an oblique angle with respect to the longitudinal axis of the frame; a reference beam channel (111, 216, 416, 516) positioned below the respective one of the sample tubes and extending at an angle from the illumination beam and not passing through the respective one of the sample tubes, wherein the reference beam channel is oriented at an oblique angle with respect to the longitudinal axis of the frame; and a reference detector (110, 210, 410, 510) positioned at the end of the reference beam channel to receive a reference beam that passes through the reference beam channel. a sample tube unit comprising a frame extending horizontally along a longitudinal axis and a plurality of sample tubes (150, 1104) connected to the frame and arranged in a line along the longitudinal axis, each sample tube extending downward in a vertical direction from the frame; a housing (120, 420, 520) having a receptacle formed therein, the receptacle extending in the vertical direction and being dimensioned to selectively receive the plurality of sample tubes therein; a plurality of sample adequacy measurement stations associated with the housing, each sample adequacy measurement station comprising: a light source (102, 202) adapted to selectively generate an illumination beam directed upwards in the vertical direction through the receptacle and into a respective one of the sample tubes; a sample detector (108, 208, 408, 508) positioned along a vertical extent of the respective one of the sample tubes and adapted to receive an emitted beam comprising at least a portion of the illumination beam scattered by turbidity in the respective one of the sample tubes, wherein the sample detector is positioned at the end of an emitted beam channel, and wherein the emitted beam channel (106, 214, 414, 514) extends in a plane that is perpendicular to the vertical direction and is oriented at an oblique angle with respect to the longitudinal axis of the frame; a reference beam channel (111, 216, 416, 516) positioned below the respective one of the sample tubes and extending at an angle from the illumination beam and not passing through the respective one of the sample tubes, wherein the reference beam channel is oriented at an oblique angle with respect to the longitudinal axis of the frame; and a reference detector (110, 210, 410, 510) positioned at the end of the reference beam channel to receive a reference beam that passes through the reference beam channel. a light source (102, 202) adapted to selectively generate an illumination beam directed upwards in the vertical direction through the receptacle and into a respective one of the sample tubes; a sample detector (108, 208, 408, 508) positioned along a vertical extent of the respective one of the sample tubes and adapted to receive an emitted beam comprising at least a portion of the illumination beam scattered by turbidity in the respective one of the sample tubes, wherein the sample detector is positioned at the end of an emitted beam channel, and wherein the emitted beam channel (106, 214, 414, 514) extends in a plane that is perpendicular to the vertical direction and is oriented at an oblique angle with respect to the longitudinal axis of the frame; a reference beam channel (111, 216, 416, 516) positioned below the respective one of the sample tubes and extending at an angle from the illumination beam and not passing through the respective one of the sample tubes, wherein the reference beam channel is oriented at an oblique angle with respect to the longitudinal axis of the frame; and a reference detector (110, 210, 410, 510) positioned at the end of the reference beam channel to receive a reference beam that passes through the reference beam channel.