A calibrating-light module for use in a system for measuring whole-blood hemoglobin parameters or whole-blood bilirubin parameters. The calibrating-light module includes a calibrating module housing, a light beam receiving portion connected to a first end of the calibrating module housing, a calibrating light portion connected to a side of the calibrating module housing wherein the side is transverse to the first end, and an optic fiber portion connected to a second end of the calibrating module housing wherein the calibrating module housing, the light beam receiving portion and the optic fiber portion are aligned with an optical path and the calibrating light portion is spaced from and transverse to the optical path.