The measurement of the physical properties (density, viscosity, surface tension, thermal conductivity, etc.) is of great importance to the research, industry and physical, chemical and biomedical applications. The thermal conductivity is a measurement of the material's ability to conduct heat. The Transient Hot Wire method is a suitable method to measure the thermal conductivity due to its very cheap cost of construction, accuracy and because it is a fast method of measurement. The implementation requires accurate temperature sensing, automatic control, data acquisition and data analysis. The basic procedure consists of measuring the temporal temperature rise in a thermoresistance (thin wire) immersed in the solution by applying an electrical current in the wire. Therefore, the wire works as a heat source and a temperature sensor. The time of measurement is very short and therefore the convection effect could be minimized. Then, the heat transfer to the infinite medium is due only to the conduction transfer effect. The thermal conductivity can be determined from the slope of the curve T versus ln(t) due to the linear relation between T and ln(t)."

The Surface Detector of the Pierre Auger Observatory consists of 1600 water Cherenkov tanks sampling ground particles of air showers produced by energetic cosmc rays. Every water tank is equipped with three photomultipliers (PMTs). Every 7 minutes monitoring data are recording from each surface detector to ensure that they are performing as intended and also to understand the detector behaviour. The monitoring data set is used to study the evolution of parameters of the PMTs as a function of both time and temperature. The main objective of this work is to monitor the stability of the PMTs. In case there is abnormal behaviour detected, an alarm entry is created in the database. The classification of the alarms into different categories, corresponding to the observed patterns of the above mentioned variables and the decision of the alarm level are subject of this research. The research has three important parts, the theoretical analysis about the deflection angle of high energy events and the threshold energy for high energy cosmic rays (GZK cuttof), the theoretical part of the photomultiplers and the analysis of them using C++, Root and MySQL and the alarms creation.