Automation photometer of Hitachi U–2000 spectrophotometer with RS–232C–based computer

The interfacing of a commonly used spectrophotometer, the Hitachi U2000, through its RS–232C port to a IBM compatible computer is described. The hardware for data acquisation was designed by suitably modifying readily available materials, and the software was written using the C programming language. The various steps involved in these procedures are elucidated in detail. The efficacy of the procedure was tested experimentally by running the visible spectrum of a cyanine dye. The spectrum was plotted through a printer hooked to the computer. The spectrum was also plotted by transforming the abscissa to the wavenumber scale. This was carried out by using another module written in C. The efficiency of the whole set-up has been calculated using standard procedures.