This work reports the calibration of the IR signals from TGA effluent gas using decomposition of solids and evaporation of liquids. The IR signal separates the TGA weight losses for quantitation, and allows a successful deconvolution of the TGA data where several compounds are evolving from the TGA at the same time. It is unnecessary to heat the transfer lines and IR cell as long as the effluent has some volatility at ambient temperature. A DSC pinhole pan makes a very effective device for the calibration of low boiling components and produces calibration data equivalent to that achieved by decomposition of solid substrates. The value of the technique is demonstrated by quantitation of overlapping components in the TGA effluent. (C) 2004 Elsevier B.V. All rights reserved.