A spectrophotometer system comprising a continuum source, monochromator, reflectometer and digital signal handling system is described. The important advantages are that; the system is totally integrated; both transmission and reflection measurements (at a range of angles) can be made; operation is simple, convenient and semi-automatic; data are produced in a suitable form for computer analysis; and steps have been taken to reduce errors arising from both optical misalignment and noise in the data and electronics.