Abstract: A spectrometric instrument passes flashing light through a sample and has a linear detector operated by the computer to integrate signals for an established number of flashes to obtain an integrated unit of the signal data, from which spectral information is displayed on a monitor. Over a full spectral range, the established number is determined as that which effects a highest peak height proximately below a preselected maximum, and light source voltage is adjusted to bring the peak height closer to the maximum. For a narrower spectral range, an operating number of flashes for a unit is increased above the established number to accommodate a lower highest peak in the range. Wavelength calibration uses peaks in the light source. Corrections are made for stray light and non-linearity of detector response. Calculation of auxiliary information derived from input of auxiliary data through a touch screen is displayed on the monitor.