Beckman DU ultraviolet photoelectric spectrophotometer, 1950s.
© Science Museum / Science & Society Picture Library
The pioneering ultraviolet-visible spectrohotometer launched by Beckman Instruments in 1941. Like many early spectrophotometers, this was a point by point instrument and could not record a continuous spectrum. Nonetheles its ruggednes, relative cheapnes and ease of use ensured its popularity in the 1940s and 1950s. A spectrophotometer is an instrument for measuring the intensity of light in various parts of the spectrum, especially as transmitted or emitted by a substance or solution at a particular wavelength.