The intense color of haemoglobin has, from the very starting, performed an important position in either the research of this compound in addition to within the learn of blood oxygen shipping. a variety of optical equipment were constructed for measuring haemoglobin focus, oxygen saturation, and the critical dyshaemoglobins in vitro in addition to in vivo. sleek purposes comprise pulse oximeters, fibre optic oximeters, multiwavelength haemoglobin photometers ('co-oximeters') and tools for close to infrared spectroscopy in vivo. wisdom of the sunshine absorption spectra of the typical haemoglobin derivatives is a prerequisite for the advance and knowing of those concepts. within the Sixties a reference approach according to the absorptivity of a unmarried by-product (haemiglobincyanide; HiCN) at a unmarried wavelength (540 nm) used to be verified for measuring the complete haemoglobin focus. therefore an anchor price used to be supplied on which the absorptivity spectra of all different haemoglobin derivatives will be established. This monograph offers absorption spectra and absorptivity info within the wavelength diversity of 480 to a thousand nm of the most important haemoglobin derivatives for human grownup and foetal haemoglobin and for haemoglobin of numerous animals (cow, puppy, horse, pig, rat, and grownup and foetal sheep). an in depth description of the equipment used to obtain those info has been integrated to permit destiny investigators to breed and extend at the facts. the second one a part of the monograph contains chapters at the rules and improvement, in historic viewpoint, of the relevant equipment for measuring overall haemoglobin focus for 2, 3, and multi-component research of haemoglobin derivatives, and for blood oxygen saturation dimension. exact quantitative information touching on haemoglobin in human blood are provided, including an outline of tools for measuring haemoglobin oxygen ability and oxygen affinity. those chapters were written so that it will foster wisdom and perception in regards to the ideas, reasons, and boundaries of some of the tools of all who use those equipment in examine and sufferer care.