Temperature rise leads to signal transmission change of vibration measurement during test run of engines.Based on electromagnetic-thermal theory

the effects of thermal field on electromagnetic field variables were studied.A new approach was proposed to extract multi-conductor transmission parameters by combining test transmission network.The parameters values obtained by proposed approach were in good agreement with classical energy method.The results show that resistance and inductance of transmission conductor increase with the rising temperature

and conductor resistance has obvious change range compared to inductance.Proximate effects of conductors aggravate along with temperature rise

and mutual electrical parameters have important changes due to temperature and distance.