Application of low-cost sensors for accurate ambient temperature monitoring

In structures with reduced monitoring budgets, the high cost of commercial metering devices is always an obstacle for monitoring structural health. This might be an issue when temperatures must be measured for both structural and environmental reasons. To fill this gap, in this paper, a novel monitoring system is proposed for the accurate measurement of indoor temperature in buildings. This protocol is characterized by its generality, as it can be easily adapted to measure any structural or environmental parameters on site. The proposed monitoring system uses from one to eight low-cost sensors to obtain multiple measurements of the ambient temperatures. The accuracy ranges of the developed monitoring systems with different numbers of sensors are statistically analysed. The results indicate that the discrepancy of the measurements decreases with the increase in the number of sensors, as the maximum standard deviation of 10 sensors (0.42) decreases to 0.32 and 0.27 for clusters of 20 and 30 sensors, respectively.This research was funded by the Spanish Ministry of Economy and Competitiveness (grant number BIA2013-47290-R, BIA2017-86811-C2-1-R, and BIA2017-86811-C2-2-R) and by the Universidad de Castilla La Mancha (grant number 2018-COB-9092).Peer ReviewedPostprint (published version

Control and regulation system for glass-house

Předmětem této práce je návrh automatického zavlažovacího systému pro skleník, který bude schopen měřit teplotu vzduchu, vlhkost vzduchu a vlhkost půdy. A na základě těchto hodnot ovládat větrání a zavlažování.The objective of this thesis is a design of automatic water system of greenhouse, which will be able measure temperature, relative humidity of air and soil. System will control air and water management based on these values.

Indoor battery-less temperature and humidity sensor for Bluetooth Low Energy

In June 2010, the Bluetooth SIG adopted the first version of Bluetooth that includes the low energy specifications (4.0). Ble has been designed to allow devices running on a small energy budget to communicate with host stations such as mobile phones or personal computers. Bluetooth low energy is primarily meant to be used in applications that require small batteries. In this work we investigated the suitability of that new wireless protocol for a battery-free application. We chose a simple and yet useful application scenario, where temperature and humidity are measured in an office environment and the results are wirelessly sent to a host. The use of the new sensor SHT21 from Sensirion allows temperature and humidity to be precisely measured with a small energy budget. For sensors to be moved and placed conveniently, a wireless system based on the EM9301 Ble radio of EM Microelectronic is implemented. The EM6819 is used as microcontroller to control the system. Energy autonomy is provided by a flexible and small solar cell from G24i. Temperature and humidity data can be displayed or transferred to the right place by using the appropriate PC or mobile phone fitted with the wireless link. As far as we know, this is the first work of this type using a battery-less sensor and Ble for communication

Chemical Analysis Of Selected Carbon Steel Artefacts From Benin City And Implications for Preservation

The use of carbon steel in the fabrication of outdoor artefacts is widespread in Nigeria. The peculiar morphology of this material makes it susceptible to atmospheric corrosion, which ultimately can weaken and destroy carbon steel artefacts and consequently their embodied aesthetic and historic values. Using Benin City, taken to be representational of other metal artefacts fabrication contexts in Nigeria as case study, this study investigated the elemental composition of some carbon steels used in the fabrication of outdoor artefacts with a view to determining finishing options for the material to withstand corrosion. Three Ion Beam Accelerator techniques: Particle-Induced X-Ray Emission Spectroscopy, Rutherford Backscattering Spectrometry and Proton Induced Gamma-Ray Emission Spectroscopy were used simultaneously to determine the elemental composition of twenty three sampled items. Optical Emission Spectrometry was also used in determining the carbon content in the items sampled. Ten elements: C, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, and Zn were detected and measured. The carbon steels compositions, when compared with global standards, were found to be deficient. This raised issues on how such materials can withstand corrosion and corollary to which the study recommended the need for Nigeria to set standards for the quality of steel produced in the country and those imported into Nigeria. Significantly, the study also recommended a two-way coating, among other finishing options, to protect outdoor carbon steel artefacts from atmospheric corrosion and that, where one cannot get good quality standard carbon steels, an in-depth knowledge of preservation techniques becomes imperative

Investigation of daily natural and rapid human effects on the air temperature of the Hajnóczy cave in Bükk mountains

The aim of this study the authors measured and analyzed the effect of the exterior daily temperature change on the interior temperature in a dripstone cave visited by cavers exclusively. The measurement was carried out in the Hajnóczy Cave located in the southern part of Bükk Mountains in Hungary. Although only one entrance is known, there are more evidences for the strong effect of exterior conditions on the interior processes like temperature fluctuation and dripstone development. Using high resolution wireless digital thermometer sensor network the air temperature and air humidity were measured in 32 points in every 10 minutes for long time but now the data of a 8-days period were analyzed. Based on these data different zones of the cave could be separated and during summer conditions the climatic variability of the entrance transitional and deep cave zone was described. Based on statistical analysis of spatial information significant correlation was found between the exterior temperature fluctuation and that of such a cave chamber, which is relatively far from the cave entrance. This fact proves that existence of a fissure system which is permeable for air but not passable for cavers. During the measurement the human effect was also analyzed and 0.3-0.6 °C temperature rising was recognized for a short time. Because of the surface vicinity the effects of the environmental change can have sensible impact on the cave and its natural phenomena. Among others temperature rising, air humidity decreasing were detected in present study

Smartphone and Bluetooth Smart Sensor Usage in IoT Applications

Bluetooth Low Energy is an interesting short-range radio technology that could be used for connecting tiny devices into the Internet of Things (IoT) through gateways or cellular networks. For example, they are widely used in various contexts, from building and home automation to wearables. This paper proposes a method to improve the use of smartphones with a smart wireless sensor network acquisition system through Bluetooth Low Energy (BLE). A new BLE Smart Sensor, which acquires environmental data, was designed and calibration methods were performed. A detailed deviation is calculated between reference sensor and sensor node. The data obtained from laboratory experiments were used to evaluate battery life of the node. An Android application for devices such as Smartphones and Tablets can be used to collect data from a smart sensor, which becomes more accurate

On the Development and Characterization of PMA-based SAW Sensing Devices

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Investigation of Daily Natural and Rapid Human Effects on the Air Temperature of The Hajnóczy Cave in Bükk Mountains

The aim of this study the authors measured and analyzed the effect of the exterior daily temperature change on the interior temperature in a dripstone cave visited by cavers exclusively. The measurement was carried out in the Hajnóczy Cave located in the southern part of Bükk Mountains in Hungary. Although only one entrance is known, there are more evidences for the strong effect of exterior conditions on the interior processes like temperature fluctuation and dripstone development. Using high resolution wireless digital thermometer sensor network the air temperature and air humidity were measured in 32 points in every 10 minutes for long time but now the data of a 8-days period were analyzed. Based on these data different zones of the cave could be separated and during summer conditions the climatic variability of the entrance transitional and deep cave zone was described. Based on statistical analysis of spatial information significant correlation was found between the exterior temperature fluctuation and that of such a cave chamber, which is relatively far from the cave entrance. This fact proves that existence of a fissure system which is permeable for air but not passable for cavers. During the measurement the human effect was also analyzed and 0.3-0.6 °C temperature rising was recognized for a short time. Because of the surface vicinity the effects of the environmental change can have sensible impact on the cave and its natural phenomena. Among others temperature rising, air humidity decreasing were detected in present study

In-shoe sensor system with an embedded user interface and wearable leg unit

In-shoe sensor systems are of great interest to monitor foot health, sports activities and rehabilitation strategies. Among the potential users are people with diabetes, a large part of the population for which monitoring foot pressure and temperature is critical to avoid ulceration, and even amputation. Despite all these reasons the use of foot monitoring devices is still uncommon compared to other accessories such as fitness tracking devices. This work describes the development of an instrumented insole for monitoring pressure, temperature and humidity taking advantage of widely available wearable components. This is made possible by additionally developing a shield board for time-division multiplexing of the pressure signals and an embedded user interface which is stored in the microcontroller's memory and uploaded to a smartphone at start-up via Bluetooth Low Energy. The user interface runs on a smartphone to provide both real time monitoring and averages of sensor data. The system is described in detail and validated by monitoring pressure patterns during stance, by testing response to temperature variations and observing patterns in individuals with pes planus posture.info:eu-repo/semantics/publishedVersio

Development of novel apparatus for establishing swelling and water retention characteristics of bentonite

Despite the breakthroughs in suction control and measurement for laboratory testing of unsaturated soils at the range of high suctions, existing equipment faces limitations in either the precision, the range, or the practicality. The aim of the present thesis is to develop novel apparatus for establishing the swelling and water retention characteristics of compacted bentonite, which may exhibit very high suctions at its as-compacted state. The development of the equipment is based upon the best elements of existing equipment, combined in a simple and efficient manner and extends the range of existing suction-controlled facilities in the Geotechnics Laboratory of Imperial College London. A new humidity generator is presented, based on the principles of the divided-flow method. The divided-flow humidity generator (dfHG) controls the relative humidity (RH) in a sealed chamber, allowing suction control of soil samples through the Vapour Equilibrium Technique (VET). The control of RH is automated and is obtained by the proportional mixing of dry and wet air based on the feedback given on RH measurements in the chamber with affordable, individually calibrated capacitance hygrometers. Direct comparison with other suction-control methods, and derivation of water retention curves for reference soil materials validate the method. The automated control and the continuous operational range of suction provides the versatility of pressure generators, while the simplicity of the system is comparable to the practicality of the air-regulation method. The humidity generator is subsequently adapted to a newly-developed oedometer, to assist in the investigation of highly expansive clays, such as bentonites. The device allows the application of continuous, automated control of suction in the range between 30 MPa and 300 MPa, while applying complex stress and hydraulic paths for swelling tests. Equilibrium on each suction step is assessed through the combined evaluation of swelling stress, RH of the outflow air and water exchanged with the soil sample. The method is validated through successful investigation of the swelling behaviour of a natural sodium bentonite.Open Acces