Testing of properties in flowable materials

摘要

Method of testing a property of a flowable substance. In particular this invention relates to the testing of the cross-linkability of an adhesive and is particularly relevant to an in-line process for mounting electronic components upon a printed circuit board. In the process, infrared light is passed through adhesive being fed to a dispensing position. Some of the light is absorbed by chemicals in the adhesive. Unabsorbed light after passing through the adhesive is analyzed and wavelengths of the light relating to cross-linkable materials in adhesive are monitored.