1) Time domain reflectometry 
Time-domain reflectometer sends a sonar like electrical pulse down a cable and can determine the location of a break in the cable.
= Time Domain Reflectrometry. TDR is a technique which is used for measuring the characteristic impedance of a printed circuit trace. The equipment measures the way in which a pulse is reflected from discontinuities in the transmission line created by the trace. 
Toxicology Desk Reference
UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases
Target Defence RunTime Domain Reflectometry
Target Data Receiver
acronym: time domain reflectometry
(NETWORK GLOSSARY) Time domain reflectometer. Device capable of sending signals through a network medium to check cable continuity and other attributes. TDRs are used to find physical layer network problems.
Time domain reflectometer. Device capable of sending signals through a network medium to check cable continuity and other attributes. TDRs are used to find physical layer network problems.
A synthetic rubber commonly used to create sticky soles on climbing shoes.