OTLM Sag measurement:
OTLM system measures sag based on real-time inclination and conductor temperature measurements combined within a mathematical model. Information gathered only with the mathematical model can be misleading. The mathematical model uses the ideal elastic flexibility without inner friction. This assumption simplifies the calculation and the OHL span is presented as a free moving conductor, whose length changes in accordance with ambient conditions like gravity, wind, ice, and sun. By implementing inclination measurements in the OTLM sensors and using the developed mathematical field-tested model, we have an accurate sag measurement. For its calculation, the software uses geometrical parameters between two handles and mechanical characteristics of the conductor. Geometric data, such as span and sag, are then bound to the temperature of the conductor. A mathematical model for the calculation of the geometry of the catenary curve and tensile strength has been developed as a basis for the continuous monitoring of the temperature and conductor inclination.
Required data to define sag:
For accurate sag measurement, OTLM company require site measurements with geodetic instrument (span with OTLM sensors) and conductor technical data. In case, the TSO is conduction site measurements, OTLM will send all instructions on how to perform the measurements.