Colorimetric involves analyzing the color of a portion in an image. In below example titrant is being added to an analyte:

We use image processing to look at the color of the solution and determine when the titration is complete. The program uses Python3 and OpenCV to analyze video on a frame-by-frame basis. Sample an image kernel from the same location on each frame and determine the average red, green, and blue channel values.

The graph shows how the three component colors (red, green, and blue) of the solution change over time; the difference in the solution’s color can be used to activate an alarm.

A similar video analytics code can be written to analyze other industrial processes or do quality control on an assembly line.

Code for above analysis is available on Github