| abstract |
A process for monitoring and/or controlling a nitrating process, having the following steps: n measuring inline infrared spectra of nitric acid content in a reaction mixture stream downstream of the nitration reaction, preferably near-infrared spectra, n evaluating the measured spectra by means of a computer-assisted, matrix-specific calibration model for the purpose of determining the content of nitric acid, n transmitting the results of spectrometric examination to a process control system, n inputting the results of spectrometric examination for the purpose of specifying the content of nitric acid in the acid phase into a regulator ( 224 ) for control of the metering ( 207, 217 ) of nitric acid into a nitrating reactor. |