This paper describes a novel technique to obtain simultaneous spectral, thermal and dilatometric data on polymers as they are heated through their glass transition temperatures and melting points. The technique links an infrared spectrometer and an optical spectrum analyser, through a combination of fibre optic probes, to a custom-modified differential scanning calorimeter (DSC). The latter is used to obtain thermal-based information such as the enthalpy of fusion and the glass transition whilst the infrared spectrometer is used to obtain chemical information of the polymer sample. The optical spectrum analyser was used in tandem with the fibre optic probe to obtain simultaneous dilatometric data from the processed sample using an interferometric technique. This combined and simultaneous analytical technique negates the need for three independent experiments to obtain thermal, spectral and chemical information. Another advantage of this simultaneous technique is that the polymer sample is subject to a single and controlled thermal environment.