System and method for determining suspension member elongation

An elevator system, comprising:

• at least one suspension member that supports an elevator car and facilitates movement of the elevator car in a hoistway;
• a counterweight coupled to the elevator car with the at least one suspension member;
• a first sensor assembly that detects a presence of one of the counterweight and the elevator car, wherein the first sensor assembly comprises at least one first sensor mounted to a fixed location in the hoistway or to a first moveable object;
• a second sensor assembly that determines a position of the other of the elevator car and counterweight within the hoistway in response to a detection signal generated by the at least one first sensor, and wherein the second sensor assembly comprises a reference tape mounted to one of a fixed structure or a second moveable object, and at least one second sensor mounted to the other of the fixed structure or the second moveable object;
• and
• a control system that determines elongation of the at least one suspension member based on a change in the position of the elevator car or the counterweight in the hoistway over time as determined in response to the detection signal.

A method wherein an elevator car is supported for movement within a hoistway by at least one suspension member and a counterweight is coupled to the elevator car with the at least one suspension member, the method comprising:

• detecting a presence of one of the counterweight and the elevator car with a first sensor;
• determining a position of the other of the elevator car and counterweight within the hoistway in response to a detection signal generated by the first sensor;
• and
• determining elongation of the at least one suspension member based on a change in the position of the elevator car or counterweight in the hoistway over time as determined in response to the detection signal.