# Smart Tags: IoT Sensors for Monitoring the Micro-Climate of Cultural Heritage Monuments
## 5 Conclusions  
In this work, we present the development of smart IoT devices that monitor specific environmental conditions in the vicinity of cultural heritage buildings. These IoT devices are designed according to the needs of multiple cultural heritage areas across the Europe, and they manage to be autonomous, power efficient and deployable in a nonintrusive way  
Figure 14: Temperature on Rhodes measured by a Smart Tag and two commercial weather stations.  
Figure 15: Relative Humidity on Rhodes at 5 January 2022 measured by a Smart Tag and two commercial weather stations.  
on the buildings' walls. Furthermore, a visualization platform is designed to present the measurements in a user-friendly way.  
Measurements acquired by multiple smart tags, installed on specific buildings across the study areas, are presented. Form these measurements, we can observe that the proposed developed system is operational and can be used as a monitor device on different climate conditions. The gathered results are compared with real data acquired by professional weather stations installed in each area. The Smart Tag's data appear to be really close to those of the weather stations with small deviations. As a result, the proposed system can be a reliable solution for monitoring specific climate conditions and a useful tool that can contribute to the assessment of the deterioration of CH buildings and the risks generated by weather phenomena. Last but not least, the NB-IoT connectivity and the power efficiency of the developed device are tested. From the results, we can conclude that the NB-IoT network offers sufficient signal even on underground locations, and the smart tag device can achieve very low power consumption and achieve long operational life.  
It is mentioned that the Smart Tags' functionality is limited on a sensor-monitor level, and it is not suitable to operate as a data processing device that executes computations with high complexity, because of its constrained resources (e.g., memory, power consumption). The data acquired by the Smart Tags can be further processed on the server's back-end side and can be used for modeling or simulation purposes.  
The solution is intensively evaluated at the time being, within the context of the HYPERION project, and we will continue to do so for over a year, until the end of the project.  
Conceptualization, N.M. and M.K.; methodology, N.M. and M.K.; sensor design, N.M.; software, N.M.; writing--original draft preparation, N.M. and M.K.; supervision, A.A.; funding acquisition, A.A. All authors have read and agreed to the published version of the manuscript.  
This work is a part of the HYPERION project, funded by the European Union's Horizon 2020 Research and Innovation Programme and the Korean Government under Grant Agreement No. 821054. Content reflects only the authors' view.  
Not applicable.  
The authors declare no conflict of interest.  
The following abbreviations are used in this manuscript:  
\begin{tabular}{l l} IoT & Internet of Things \\ CH & Cultural Heritage \\ CC & Climate Change \\ MCU & Microcontroller Unit \\ SPIFFS & Serial Peripheral Interface Flash Filing System \\ LPWAN & Low Power Wide Area Networks \\ NB-IoT & NarrowBand Internet of Things \\ ULP & Ultra Low Power \\ RTC & Real Time Clock \\ I2C & Inter-Integrated Circuit \\ GPIO & General-Purpose Input/Output \\ UART & Universal asynchronous receiver-transmitter \\ SPI & Serial Peripheral Interface \\ ADC & Analog to Digital Converter \\ PCB & Printed Circuit Board \\ SMT & Surface Mount Technology \\ ABS & Acrylonitrile Butadiene Styrene \\ MQTT & Message Queuing Telemetry Transport \\ \end{tabular}