Identification of Dynamic Properties of the Intrinsically Safe Barrier for Telephone System

Telephone communication in spaces endangered by explosion (for instance, methane mines) requires to use the intrinsically safe barriers that interconnect nonintrinsically safe telephone exchange and intrinsically safe telecommunication network. Using the computer tester the frequency characteristics of chain matrix elements of the barrier of SD-3 type have been measured. Then, the barrier identification has been made and chain matrix elements were obtained as suitable order rational functions transmittances. Chain matrix of separate fragments of barrieascomputed on the basis of analysis of schematic diagram (except for DCIDC converter, whose transmittance has been measured). Chain matrix of barrier was calculated as a product of matrices of all elements of barrier. Measured transmittances were compared with computed ones. The transmittances obtained can be considered as barrier models useful to analyse telephone signals transmissions in mine telecommunication networks.