<Li> <P> TDR trace of a transmission line with an open termination </P> </Li> <P> TDR trace of a transmission line with an open termination </P> <Li> <P> TDR trace of a transmission line with a short circuit termination </P> </Li> <P> TDR trace of a transmission line with a short circuit termination </P>

Explain what a tdr is and describe how it is used.​