The instrument was imported to Japan right after its release in the U.S. The quantitative accuracy of the imported UV-VIS spectrophotometer was significantly better than that of the colorimeters being used in Japan at that time. As a result, it became a major topic of discussion in the field of analytic chemistry, and at the same time, great hopes came to be held for a Japanese produced version. In response to this demand, engineers at Shimadzu proceeded with development through trial and error, using a sketch of the American UV-VIS spectrophotometer as a reference.
They were confronted with a problem however. While the American UV-VIS spectrophotometer used a hydrogen discharge tube as the light source for wavelengths of 400 nm or less in the ultraviolet region, no such tube was being produced in Japan at the time. Accordingly, Shimadzu called for cooperation on its affiliate, Japan Storage Battery Co., Ltd. (now GS Yuasa Corporation), which manufactured mercury lamps at the time, and was able to produce a hydrogen discharge tube rivaling those produced in the U.S.
While the UV-VIS spectrophotometers imported from the U.S. used a photoelectric tube as the detector, photomultiplier tubes, which provided several hundred times more sensitivity, came to be manufactured in the U.S. Accordingly, Shimadzu asked a Japanese photoelectric tube manufacturer to participate in collaborative research on photomultiplier tubes. Through the untiring efforts of this photoelectric tube manufacturer, a photomultiplier tube with performance rivaling American made models was then completed.
Relationship Between Wavelength and Color
Dispersion Using a Prism
|A photoelectric tube is a vacuum tube that uses the photoelectric effect to convert light energy into electrical energy. A photomultiplier tube adds current amplification functionality to the performance of a photoelectric tube. At present, photomultiplier tubes are used as the detector in UV-VIS spectrophotometers.||A colored liquid will absorb light at a specific wavelength. Using this phenomenon, a colorimeter measures light by utilizing a glass filter through which light at this specific wavelength passes. Various types of colorimeters have been developed. The photograph shows a Stammer-Engler colorimeter.||This is a type of discharge tube containing a minute quantity of hydrogen and is used as an ultraviolet light source. When such tubes contain deuterium, they are referred to as deuterium lamps. Deuterium lamps are used in UV-VIS spectrophotometers because they have strong irradiation intensity in comparison to light hydrogen.|