Rope tension measuring apparatus for use with an elevator

A rope tension measuring apparatus for use with an elevator of the type that measures a rope tension of a main rope that suspends a car and a counterweight, comprising:

• travelling wave detector means for detecting a travelling wave occurring in the main rope in response to a displacement that is applied to the main rope and for outputting a detector output signal;
• and
• a portable measuring device that computes and outputs at least one calculated value corresponding to said rope tension based on the detector output signal from the travelling wave detector means,
• wherein the portable measuring device comprises:
• traveling-wave passage information computing means for computing passage information including at least a return time of the traveling wave based on the detector output signal from said traveling wave detector means,
• adjustment quantity computing means for computing a rope tension adjustment quantity including at least a spring adjustment quantity for a main rope tension adjusting spring based on said passage information, and
• output means for outputting a first calculation value of the spring adjustment quantity.