This document specifies requirements and test methods for surveillance systems for directly buried hot water networks in accordance with EN 13941 1 and EN 13941 2.This document specifies requirements for the manufacture of measuring elements, for the manufacture of factory made bonded pipe, fitting and valve assemblies with measuring elements as well as for the assembly of the measuring elements in the field.All requirements and recommendations described in this document are based on the experience gained with existing surveillance systems and their principle function.The specific requirements given are only valid for electrical wire based surveillance systems forming an integral part of the pipes, valves, fittings and joints.