| 摘要 |
<p>PURPOSE: A method and flow system for spectrometry and a cuvette for the flow system is provided to improve analysis of a liquid food product, possibly containing dissolved gases, especially milk and milk products in a dairy by using IR spectrometry for analysis of liquid food products and IR-absorbance spectrum in the MID-IR or NIR-range. CONSTITUTION: A liquid sample is extracted from the process line to a measuring branch, the sample is thermostatic and passed to a measurement cuvette. The IR-absorbance spectrum is measured, e.g. in the MID-IR or NIR-range. In order to obtain an on-line monitoring of the process line the liquid food sample is extracted directly from the process line into the measurement branch, in which the pressure is maintained at least as high as in the adjacent process line. The high pressure ensures that dissolved air will stay dissolved in the liquid food. Before each new sample the measurement branch and cuvette are flushed by high flow rates with a part of the new sample to clean the cuvette. The measurement cuvette has strong windows, preferably diamond windows to stand a high pressure and high flow rates. The on-line system is arranged to carry out e.g. 120 measurements per hour.</p> |
