The electrical resistance of a polymer is directly related to its viscosity and temperature as it has been experimentally shown (graph). Based on this observation a software has been developed in combination with OptiMold for the real-time monitoring of the resin’s viscosity in a mould cavity, in a pot or in the feeding lines in order to verify the onset of viscosity rise. In combination with the appropriate sensor it can be used either in liquid composite moulding or with prepregs. Especially for prepregs it is very important that the monitoring system identifies the minimum viscosity point ensuring that the autoclave pressure is applied at the right time.