All needed tools are supplied with the devices (one set per two devices). 
The temperature/sag/tension of an energized conductor can be measured. The line rating cannot be measured. It is calculated based on assumed or measured weather and line parameter data. Comparing the conductor temperature to the temperature limit tells the operator whether the line is operate the line but gives no guidance concerning what maximum current is allowed. The line's thermal rating tells the operator directly what the maximum allowable current is. Certain sophisticated procedures can also yield predictions of thermal ratings to warn the operator of future problems.
Dynamically rating equipment is important, since usually more load can be transferred. This is important considering open access of transmission lines, uncertain load growth, economic energy transfers, permitting new lines, expense of new lines, and maintaining high reliability. Without measuring actual weather, equipment must be severely under-rated to account for the occurrence of worst-case weather. By dynamically rating, the operator knows the true circuit rating and can therefore make smart decisions when contingencies arise or when there are pending economic energy transfers.
OTLM system can function without the OTLM device. But have in mind, that using only the weather station we are “calculating” conducted temperature. From our experience using only the mathematical model for Ampacity or alerting can be misleading. OTLM system combines measured weather data with conductor temperature and sag measurement.
There is no risk conductor damage during OTLM installation. 
If OTLM device  fails, you will immediately see offline status in OTLM Center- software.  All previous measurements (history) are stored in server database and device - last 2.000 measurements. At the same time, you will receive an email that one OTLM device is not in function.   
  If  hydraulic jack is on the site, then we need approximately 15 min to install OTLM device.   
OTLM system allows integration with SCADA with delivery of the key information’s to system operator for optimising the flow of energy. Data exchange with SCADA systems or the technical system is reversible and depends on the requirements of the customer. In our case SCADA delivers measurements of flow and also receives information on available transmission capacity transmission line.
Dynamic rating system allows for greater utilization and operational safety of new and existing power lines. Lines are designed to the unfavorable weather conditions which during a year occur rarely, therefor unused transmission capacity remains. Dynamic system provides secure utilization of the line and provides future optimization for building new lines. One of revenue TSO is linked to energy consumption (MWh), so the investment in thermal monitoring should not be seen only as a cost but as a tool that allows us to utilize infrastructure and additional income. What is more, when accident occurs, the dynamic system allows us to reliably divert the remaining lines, thus reducing the possibility of no electricity supply.
Due to changing climatic conditions along the route of the OHL, examination of the line is required for determination of critical, warmest points. The critical points limit the maximum utilization of overhead and affect on safe operation. Examples of critical points are: when OHL is changing direction (different impact of wind - cooling), crossing rivers and roads, various leeward positions on the route of the transmission line, such as changes in the forest.