SpectrophotometerIn 1935, the first U.S. patent for a spectrophotometer was issued to Professor Arthur Cobb Hardy of Wellesley, Mass. (No. 1,987,441) which he called a “photometric apparatus.”It could detect two million different shades of colour and make a permanent record chart of the results. The patent was assigned to the General Electric Company of Schenectady, N.Y. which sold the first machine on 24 May 1935. It used a photo-electric device to receive light alternately from a sample and from a standard for comparison. It eliminated any need for the two beams (from sample and from standard) to travel different optical paths which in previous designs could introduce inaccuracies if one path varied from the other.«[Image: a "GE-Hardy" double-beam recording spectrophotometer photographed in 1938 showing Walt Disney with the instrument at his studios.] |
