A method and apparatus for measuring tension imposed on a cable by a pull line in a conduit includes a tension meter coupled between the cable and the pull line. The meter includes a load cell connected to an electronic circuit to operate an audio transmitter in one embodiment, or to generate an electromagnetic...http://www.google.de/patents/US4461459?utm_source=gb-gplus-sharePatent US4461459 - Method and apparatus to measure tension in a pull line for cable
