Today's energy consumption and energy demand is increasing. That is particularly true in case of electric power consumption. The electric power is transferred from the power plants to cities and other consumers through the transmission network. The transmission lines should operate on the designed voltage and ampacity of the line, but due to the increased demands, some of the lines are already operating on elevated temperatures. To resolve that issue the capacity of the transmission network should be increased. Dynamic Line Rating, DLR is one of the most cost effective way to increase the transmission capacity of the already existing network. DLR is an operating method, which makes it possible to utilise better the network, based on real time data and calculations. The DLR system is based on sensors which provide the essential data for the system. These systems are complex electrical equipment which has to function reliably and properly after installing it directly on the conductor. These sensors have to be tested and fitted to operate in high voltage environment. At that part of the production, the standards guide the manufacturers, but in this case that is not so simple. Most of the IEC and CISPR standards are not stating clear levels of acceptance or tolerance, hence the standards are not fitted to high voltage applications. The purpose of this paper is to present the deficiencies and inaccuracies of the existing standards. Also to give basic suggestions and guidelines to solve these issues.