2,855 research outputs found
Development and Analysis of Low-Cost IoT Sensors for Urban Environmental Monitoring
The accelerated pace of urbanization is having a major impact over the world’s environment. Although urban dwellers have higher living standards and can access better public services as compared to their rural counterparts, they are usually exposed to poor environmental conditions such as air pollution and noise. In order for municipalities and citizens to mitigate the negative effects of pollution, the monitoring of certain parameters, such as air quality and ambient sound levels, both in indoor and outdoor locations, has to be performed. The current paper presents a complete solution that allows the monitoring of ambient parameters such as Volatile Organic Compounds, temperature, relative humidity, pressure, and sound intensity levels both in indoor and outdoor spaces. The presented solution comprises of low-cost, easy to deploy, wireless sensors and a cloud application for their management and for storing and visualizing the recorded data
Low cost air quality monitoring: comparing the energy consumption of an arduino against a raspberry Pi based system
Air pollution is one of the great challenges facing modern cities. According to the World Health Organization (WHO), 80% of people living in cities with air quality monitoring facilities are living in conditions where the quality of the air is well beyond the limits set out in the air quality guidelines. As more and more people are projected to move into urban areas by 2050, this problem is going to keep on increasing. A possible solution could be the advent of Smart Cities. One of the objectives of Smart Cities is to provide a better living environment to its inhabitants. With the Internet of Things providing easily deployable, low power, low cost air quality monitoring sensors and the resources to process the huge amount of data collected, this objective could be reached. In this paper, we propose an evaluation of the power consumption of two low cost air quality monitoring systems - one based on an Arduino and the other on a Raspberry Pi system. The air quality systems proposed are based on off-the shelf hardware and are easy to assemble and maintain. The proposed systems use Bluetooth Low Energy (BLE) to transmit data while being collected through a mobile app on a smartphone. The data was collected for five days and it was found by performing an ANOVA on the power consumption that there was a significant difference in the mean energy consumption of the two systems
Internet of Things Architectures for Enhanced Living Environments
Ambient Assisted Living (AAL) is an emerging multidisciplinary research area that aims to create
an ecosystem of different types of sensors, computers, mobile devices, wireless networks, and
software applications for enhanced living environments and occupational health. There are
several challenges in the development and implementation of an effective AAL system, such as
system architecture, human-computer interaction, ergonomics, usability, and accessibility.
There are also social and ethical challenges, such as acceptance by seniors and the privacy and
confidentiality that must be a requirement of AAL devices. It is also essential to ensure that
technology does not replace human care and is used as a relevant complement.
The Internet of Things (IoT) is a paradigm where objects are connected to the Internet and
support sensing capabilities. IoT devices should be ubiquitous, recognize the context, and
support intelligence capabilities closely related to AAL. Technological advances allow defining
new advanced tools and platforms for real-time health monitoring and decision making in the
treatment of various diseases. IoT is a suitable approach to building healthcare systems, and it
provides a suitable platform for ubiquitous health services, using, for example, portable sensors
to carry data to servers and smartphones for communication. Despite the potential of the IoT
paradigm and technologies for healthcare systems, several challenges to be overcome still
exist. The direction and impact of IoT in the economy are not clearly defined, and there are
barriers to the immediate and ubiquitous adoption of IoT products, services, and solutions.
Several sources of pollutants have a high impact on indoor living environments. Consequently,
indoor air quality is recognized as a fundamental variable to be controlled for enhanced health
and well-being. It is critical to note that typically most people occupy more than 90% of their
time inside buildings, and poor indoor air quality negatively affects performance and
productivity.
Research initiatives are required to address air quality issues to adopt legislation and real-time
inspection mechanisms to improve public health, not only to monitor public places, schools,
and hospitals but also to increase the rigor of building rules. Therefore, it is necessary to use
real-time monitoring systems for correct analysis of indoor air quality to ensure a healthy
environment in at least public spaces. In most cases, simple interventions provided by
homeowners can produce substantial positive impacts on indoor air quality, such as avoiding
indoor smoking and the correct use of natural ventilation.
An indoor air quality monitoring system helps the detection and improvement of air quality
conditions. Local and distributed assessment of chemical concentrations is significant for safety (e.g., detection of gas leaks and monitoring of pollutants) as well as to control heating,
ventilation, and HVAC systems to improve energy efficiency. Real-time indoor air quality
monitoring provides reliable data for the correct control of building automation systems and
should be assumed as a decision support platform on planning interventions for enhanced living
environments. However, the monitoring systems currently available are expensive and only
allow the collection of random samples that are not provided with time information. Most
solutions on the market only allow data consulting limited to device memory and require
procedures for downloading and manipulating data with specific software. In this way, the
development of innovative environmental monitoring systems based on ubiquitous technologies
that allow real-time analysis becomes essential.
This thesis resulted in the design and development of IoT architectures using modular and
scalable structures for air quality monitoring based on data collected from cost-effective
sensors for enhanced living environments. The proposed architectures address several
concepts, including acquisition, processing, storage, analysis, and visualization of data. These
systems incorporate an alert management Framework that notifies the user in real-time in poor
indoor air quality scenarios. The software Framework supports multiple alert methods, such as
push notifications, SMS, and e-mail. The real-time notification system offers several advantages
when the goal is to achieve effective changes for enhanced living environments. On the one
hand, notification messages promote behavioral changes. These alerts allow the building
manager to identify air quality problems and plan interventions to avoid unhealthy air quality
scenarios. The proposed architectures incorporate mobile computing technologies such as
mobile applications that provide ubiquitous air quality data consulting methods s. Also, the
data is stored and can be shared with medical teams to support the diagnosis.
The state-of-the-art analysis has resulted in a review article on technologies, applications,
challenges, opportunities, open-source IoT platforms, and operating systems. This review was
significant to define the IoT-based Framework for indoor air quality supervision. The research
leads to the development and design of cost-effective solutions based on open-source
technologies that support Wi-Fi communication and incorporate several advantages such as
modularity, scalability, and easy installation. The results obtained are auspicious, representing
a significant contribution to enhanced living environments and occupational health.
Particulate matter (PM) is a complex mixture of solid and liquid particles of organic and
inorganic substances suspended in the air. Moreover, it is considered the pollutant that affects
more people. The most damaging particles to health are ≤PM10 (diameter 10 microns or less),
which can penetrate and lodge deep within the lungs, contributing to the risk of developing
cardiovascular and respiratory diseases as well as lung cancer. Taking into account the adverse
health effects of PM exposure, an IoT architecture for automatic PM monitoring was proposed.
The proposed architecture is a PM real-time monitoring system and a decision-making tool. The
solution consists of a hardware prototype for data acquisition and a Web Framework developed in .NET for data consulting. This system is based on open-source and technologies, with several
advantages compared to existing systems, such as modularity, scalability, low-cost and easy
installation. The data is stored in a database developed in SQL SERVER using .NET Web services.
The results show the ability of the system to analyze the indoor air quality in real-time and the
potential of the Web Framework for the planning of interventions to ensure safe, healthy, and
comfortable conditions.
Associations of high concentrations of carbon dioxide (CO2) with low productivity at work and
increased health problems are well documented. There is also a clear correlation between high
levels of CO2 and high concentrations of pollutants in indoor air. There are sufficient reasons
to monitor CO2 and provide real-time notifications to improve occupational health and provide
a safe and healthy indoor living environment. Taking into account the significant influence of
CO2 for enhanced living environments, a real-time IoT architecture for CO2 monitoring was
proposed. CO2 was selected because it is easy to measure and is produced in quantity (by people
and combustion equipment). It can be used as an indicator of other pollutants and, therefore,
of air quality in general. The solution consists of a hardware prototype for data acquisition
environment, a Web software, and a smartphone application for data consulting. The proposed
architecture is based on open-source technologies, and the data is stored in a SQL SERVER
database. The mobile Framework allows the user not only to consult the latest data collected
but also to receive real-time notifications in poor indoor air quality scenarios, and to configure
the alerts threshold levels. The results show that the mobile application not only provides easy
access to real-time air quality data, but also allows the user to maintain parameter history and
provide a history of changes. Consequently, this system allows the user to analyze in a precise
and detailed manner the behavior of air quality.
Finally, an air quality monitoring solution was implemented, consisting of a hardware prototype
that incorporates only the MICS-6814 sensor as the detection unit. This system monitors various
air quality parameters such as NH3 (ammonia), CO (carbon monoxide), NO2 (nitrogen dioxide),
C3H8 (propane), C4H10 (butane), CH4 (methane), H2 (hydrogen) and C2H5OH (ethanol). The
monitoring of the concentrations of these pollutants is essential to provide enhanced living
environments. This solution is based on Cloud, and the collected data is sent to the ThingSpeak
platform. The proposed Framework combines sensitivity, flexibility, and measurement
accuracy in real-time, allowing a significant evolution of current air quality controls. The results
show that this system provides easy, intuitive, and fast access to air quality data as well as
relevant notifications in poor air quality situations to provide real-time intervention and
improve occupational health. These data can be accessed by physicians to support diagnoses
and correlate the symptoms and health problems of patients with the environment in which
they live. As future work, the results reported in this thesis can be considered as a starting point for the
development of a secure system sharing data with health professionals in order to serve as
decision support in diagnosis.Ambient Assisted Living (AAL) é uma área de investigação multidisciplinar emergente que visa
a construção de um ecossistema de diferentes tipos de sensores, microcontroladores,
dispositivos móveis, redes sem fios e aplicações de software para melhorar os ambientes de
vida e a saúde ocupacional. Existem muitos desafios no desenvolvimento e na implementação
de um sistema AAL, como a arquitetura do sistema, interação humano-computador, ergonomia,
usabilidade e acessibilidade. Existem também problemas sociais e éticos, como a aceitação por
parte dos utilizadores mais vulneráveis e a privacidade e confidencialidade, que devem ser uma
exigência de todos os dispositivos AAL. De facto, também é essencial assegurar que a tecnologia
não substitua o cuidado humano e seja usada como um complemento essencial.
A Internet das Coisas (IoT) é um paradigma em que os objetos estão conectados à Internet e
suportam recursos sensoriais. Tendencialmente, os dispositivos IoT devem ser omnipresentes,
reconhecer o contexto e ativar os recursos de inteligência ambiente intimamente relacionados
ao AAL. Os avanços tecnológicos permitem definir novas ferramentas avançadas e plataformas
para monitorização de saúde em tempo real e tomada de decisão no tratamento de várias
doenças. A IoT é uma abordagem adequada para construir sistemas de saúde sendo que oferece
uma plataforma para serviços de saúde ubíquos, usando, por exemplo, sensores portáteis para
recolha e transmissão de dados e smartphones para comunicação. Apesar do potencial do
paradigma e tecnologias IoT para o desenvolvimento de sistemas de saúde, muitos desafios
continuam ainda por ser resolvidos. A direção e o impacto das soluções IoT na economia não
está claramente definido existindo, portanto, barreiras à adoção imediata de produtos, serviços
e soluções de IoT.
Os ambientes de vida são caracterizados por diversas fontes de poluentes. Consequentemente,
a qualidade do ar interior é reconhecida como uma variável fundamental a ser controlada de
forma a melhorar a saúde e o bem-estar. É importante referir que tipicamente a maioria das
pessoas ocupam mais de 90% do seu tempo no interior de edifícios e que a má qualidade do ar
interior afeta negativamente o desempenho e produtividade.
É necessário que as equipas de investigação continuem a abordar os problemas de qualidade do
ar visando a adoção de legislação e mecanismos de inspeção que atuem em tempo real para a
melhoraria da saúde e qualidade de vida, tanto em locais públicos como escolas e hospitais e
residências particulares de forma a aumentar o rigor das regras de construção de edifícios. Para
tal, é necessário utilizar mecanismos de monitorização em tempo real de forma a possibilitar
a análise correta da qualidade do ambiente interior para garantir ambientes de vida saudáveis.
Na maioria dos casos, intervenções simples que podem ser executadas pelos proprietários ou ocupantes da residência podem produzir impactos positivos substanciais na qualidade do ar
interior, como evitar fumar em ambientes fechados e o uso correto de ventilação natural.
Um sistema de monitorização e avaliação da qualidade do ar interior ajuda na deteção e na
melhoria das condições ambiente. A avaliação local e distribuída das concentrações químicas é
significativa para a segurança (por exemplo, deteção de fugas de gás e supervisão dos
poluentes) bem como para controlar o aquecimento, ventilação, e sistemas de ar condicionado
(HVAC) visando a melhoria da eficiência energética. A monitorização em tempo real da
qualidade do ar interior fornece dados fiáveis para o correto controlo de sistemas de automação
de edifícios e deve ser assumida com uma plataforma de apoio à decisão no que se refere ao
planeamento de intervenções para ambientes de vida melhorados. No entanto, os sistemas de
monitorização atualmente disponíveis são de alto custo e apenas permitem a recolha de
amostras aleatórias que não são providas de informação temporal. A maioria das soluções
disponíveis no mercado permite apenas a acesso ao histórico de dados que é limitado à memória
do dispositivo e exige procedimentos de download e manipulação de dados com software
proprietário. Desta forma, o desenvolvimento de sistemas inovadores de monitorização
ambiente baseados em tecnologias ubíquas e computação móvel que permitam a análise em
tempo real torna-se essencial.
A Tese resultou na definição e no desenvolvimento de arquiteturas para monitorização da
qualidade do ar baseadas em IoT. Os métodos propostos são de baixo custo e recorrem a
estruturas modulares e escaláveis para proporcionar ambientes de vida melhorados. As
arquiteturas propostas abordam vários conceitos, incluindo aquisição, processamento,
armazenamento, análise e visualização de dados. Os métodos propostos incorporam
Frameworks de gestão de alertas que notificam o utilizador em tempo real e de forma ubíqua
quando a qualidade do ar interior é deficiente. A estrutura de software suporta vários métodos
de notificação, como notificações remotas para smartphone, SMS (Short Message Service) e email.
O método usado para o envio de notificações em tempo real oferece várias vantagens
quando o objetivo é alcançar mudanças efetivas para ambientes de vida melhorados. Por um
lado, as mensagens de notificação promovem mudanças de comportamento. De facto, estes
alertas permitem que o gestor do edifício e os ocupantes reconheçam padrões da qualidade do
ar e permitem também um correto planeamento de intervenções de forma evitar situações em
que a qualidade do ar é deficiente. Por outro lado, o sistema proposto incorpora tecnologias
de computação móvel, como aplicações móveis, que fornecem acesso omnipresente aos dados
de qualidade do ar e, consequentemente, fornecem soluções completas para análise de dados.
Além disso, os dados são armazenados e podem ser partilhados com equipas médicas para
ajudar no diagnóstico.
A análise do estado da arte resultou na elaboração de um artigo de revisão sobre as tecnologias,
aplicações, desafios, plataformas e sistemas operativos que envolvem a criação de arquiteturas
IoT. Esta revisão foi um trabalho fundamental na definição das arquiteturas propostas baseado em IoT para a supervisão da qualidade do ar interior. Esta pesquisa conduz a um
desenvolvimento de arquiteturas IoT de baixo custo com base em tecnologias de código aberto
que operam como um sistema Wi-Fi e suportam várias vantagens, como modularidade,
escalabilidade e facilidade de instalação. Os resultados obtidos são muito promissores,
representando uma contribuição significativa para ambientes de vida melhorados e saúde
ocupacional.
O material particulado (PM) é uma mistura complexa de partículas sólidas e líquidas de
substâncias orgânicas e inorgânicas suspensas no ar e é considerado o poluente que afeta mais
pessoas. As partículas mais prejudiciais à saúde são as ≤PM10 (diâmetro de 10 micrómetros ou
menos), que podem penetrar e fixarem-se dentro dos pulmões, contribuindo para o risco de
desenvolver doenças cardiovasculares e respiratórias, bem como de cancro do pulmão. Tendo
em consideração os efeitos negativos para a saúde da exposição ao PM foi desenvolvido numa
primeira fase uma arquitetura IoT para monitorização automática dos níveis de PM. Esta
arquitetura é um sistema que permite monitorização de PM em tempo real e uma ferramenta
de apoio à tomada de decisão. A solução é composta por um protótipo de hardware para
aquisição de dados e um portal Web desenvolvido em .NET para consulta de dados. Este sistema
é baseado em tecnologias de código aberto com várias vantagens em comparação aos sistemas
existentes, como modularidade, escalabilidade, baixo custo e fácil instalação. Os dados são
armazenados numa base de dados desenvolvida em SQL SERVER e são enviados com recurso a
serviços Web. Os resultados mostram a capacidade do sistema de analisar em tempo real a
qualidade do ar interior e o potencial da Framework Web para o planeamento de intervenções
com o objetivo de garantir condições seguras, saudáveis e confortáveis.
Associações de altas concentrações de dióxido de carbono (CO2) com défice de produtividade
no trabalho e aumento de problemas de saúde encontram-se bem documentadas. Existe
também uma correlação evidente entre altos níveis de CO2 e altas concentrações de poluentes
no ar interior. Tendo em conta a influência significativa do CO2 para a construção de ambientes
de vida melhorados desenvolveu-se uma solução de monitorização em tempo real de CO2 com
base na arquitetura de IoT. A arquitetura proposta permite também o envio de notificações em
tempo real para melhorar a saúde ocupacional e proporcionar um ambiente de vida interior
seguro e saudável. O CO2 foi selecionado, pois é fácil de medir e é produzido em quantidade
(por pessoas e equipamentos de combustão). Assim, pode ser usado como um indicador de
outros poluentes e, portanto, da qualidade do ar em geral. O método proposto é composto por
um protótipo de hardware para aquisição de dados, um software Web e uma aplicação
smartphone para consulta de dados. Esta arquitetura é baseada em tecnologias de código
aberto e os dados recolhidos são armazenados numa base de dados SQL SERVER. A Framework
móvel permite não só consultar em tempo real os últimos dados recolhidos, receber
notificações com o objetivo de avisar o utilizador quando a qualidade do ar está deficiente,
mas também para configurar alertas. Os resultados mostram que a Framework móvel fornece não apenas acesso fácil aos dados da qualidade do ar em tempo real, mas também permite ao
utilizador manter o histórico de parâmetros. Assim este sistema permite ao utilizador analisar
de maneira precisa e detalhada o comportamento da qualidade do ar interior.
Por último, é proposta uma arquitetura para monitorização de vários parâmetros da qualidade
do ar, como NH3 (amoníaco), CO (monóxido de carbono), NO2 (dióxido de azoto), C3H8
(propano), C4H10 (butano), CH4 (metano), H2 (hidrogénio) e C2H5OH (etanol). Esta arquitetura é
composta por um protótipo de hardware que incorpora unicamente o sensor MICS-6814 como
unidade de deteção. O controlo das concentrações destes poluentes é extremamente relevante
para proporcionar ambientes de vida melhorados. Esta solução tem base na Cloud sendo que os
dados recolhidos são enviados para a plataforma ThingSpeak. Esta Framework combina
sensibilidade, flexibilidade e precisão de medição em tempo real, permitindo uma evolução
significativa dos atuais sistemas de monitorização da qualidade do ar. Os resultados mostram
que este sistema fornece acesso fácil, intuitivo e rápido aos dados de qualidade do ar bem
como notificações essenciais em situações de qualidade do ar deficiente de forma a planear
intervenções em tempo útil e melhorar a saúde ocupacional. Esses dados podem ser acedidos
pelos médicos para apoiar diagnósticos e correlacionar os sintomas e problemas de saúde dos
pacientes com o ambiente em que estes vivem.
Como trabalho futuro, os resultados reportados nesta Tese podem ser considerados um ponto
de partida para o desenvolvimento de um sistema seguro para partilha de dados com
profissionais de saúde de forma a servir de suporte à decisão no diagnóstico
Development of low-cost indoor air quality monitoring devices: Recent advancements
The use of low-cost sensor technology to monitor air pollution has made remarkable strides in the last decade. The development of low-cost devices to monitor air quality in indoor environments can be used to understand the behaviour of indoor air pollutants and potentially impact on the reduction of related health impacts. These user-friendly devices are portable, require low-maintenance, and can enable near real-time, continuous monitoring. They can also contribute to citizen science projects and community-driven science. However, low-cost sensors have often been associated with design compromises that hamper data reliability. Moreover, with the rapidly increasing number of studies, projects, and grey literature based on low-cost sensors, information got scattered. Intending to identify and review scientifically validated literature on this topic, this study critically summarizes the recent research pertinent to the development of indoor air quality monitoring devices using low-cost sensors. The method employed for this review was a thorough search of three scientific databases, namely: ScienceDirect, IEEE, and Scopus. A total of 891 titles published since 2012 were found and scanned for relevance. Finally, 41 research articles consisting of 35 unique device development projects were reviewed with a particular emphasis on device development: calibration and performance of sensors, the processor used, data storage and communication, and the availability of real-time remote access of sensor data. The most prominent finding of the study showed a lack of studies consisting of sensor performance as only 16 out of 35 projects performed calibration/validation of sensors. An even fewer number of studies conducted these tests with a reference instrument. Hence, a need for more studies with calibration, credible validation, and standardization of sensor performance and assessment is recommended for subsequent research
Indoor Air Quality Monitoring for Enhanced Healthy Buildings
Since most people spend 90% of their time indoors, the indoor environment has a determining influence on human health. In many instances, the air quality parameters are very different from those defined as healthy values. Using real-time monitoring, occupants or the building manager can decide and control behaviors and interventions to improve indoor air quality. The historical database is also useful for assisting doctors to support the medical diagnosis. The continuous technological advancements notably, as regards, networking, sensors, and embedded devices have made it possible to monitor and provide assistance to people in their homes. Smart objects with great capabilities for sensing and connecting could revolutionize the way we are monitoring our environment. This chapter consists of a general overview of several real-time monitoring systems developed and published by the authors. In this chapter, the authors present several new open-source and cost-effective systems that had been developed for monitoring environmental parameters, always with the aim of improving indoor air quality for enhanced healthy buildings
AN INTEGRATED APPROACH FOR POLLUTION MONITORING: SMART ACQUIREMENT AND SMART INFORMATION
Air quality is a factor of primary importance for the quality of life. The increase of the pollutants percentage in the air can cause serious
problems to the human and environmental health. For this reason it is essential to monitor its values to prevent the consequences of an
excessive concentration, to reduce the pollution production or to avoid the contact with major pollutant concentration through the
available tools. Some recently developed tools for the monitoring and sharing of the data in an effective system permit to manage the
information in a smart way, in order to improve the knowledge of the problem and, consequently, to take preventing measures in favour
of the urban air quality and human health. In this paper, the authors describe an innovative solution that implements geomatics sensors
(GNSS) and pollutant measurement sensors to develop a low cost sensor for the acquisition of pollutants dynamic data using a mobile
platform based on bicycles. The acquired data can be analysed to evaluate the local distribution of pollutant density and shared through
web platforms that use standard protocols for an effective smart use
An IoT-based solution for monitoring a fleet of educational buildings focusing on energy efficiency
Raising awareness among young people and changing their behaviour and habits concerning energy usage iskey to achieving sustained energy saving. Additionally, young people are very sensitive to environmental protection so raising awareness among children is much easier than with any other group of citizens. This work examinesways to create an innovative Information & Communication Technologies (ICT) ecosystem (including web-based, mobile, social and sensing elements) tailored specifically for school environments, taking into account both theusers (faculty, staff, students, parents) and school buildings, thus motivating and supporting young citizenś behavioural change to achieve greater energy efficiency. A mixture of open-source IoT hardware and proprietary platforms on the infrastructure level, are currently being utilized for monitoring a fleet of 18 educational buildings across 3 countries, comprising over 700 IoT monitoring points. Hereon presented is the system's high-level architecture, as well as several aspects of its implementation, related to the application domain of educational building monitoring and energy efficiency. The system is developed based on open-source technologies andservices in order to make it capable of providing open IT-infrastructure and support from different commercial hardware/sensor vendors as well as open-source solutions. The system presented can be used to develop and offer newapp-based solutions that can be used either for educational purposes or for managing the energy efficiency ofthebuilding. The system is replicable and adaptable to settings that may be different than the scenarios envisionedhere (e.g., targeting different climate zones), different IT infrastructures and can be easily extended to accommodate integration with other systems. The overall performance of the system is evaluated in real-world environment in terms of scalability, responsiveness and simplicity
VentQsys: Low-cost open IoT system for CO2 monitoring in classrooms
In educational context, a source of nuisance for students is carbon dioxide (CO2) concentration due to closed rooms and lack of ventilation or circulatory air. Also, in the pandemic context, ventilation in indoor environments has been proven as a good tool to control the COVID-19 infections. In this work, it is presented a low cost IoT-based open-hardware and open-software monitoring system to control ventilation, by measuring carbon dioxide (CO2), temperature and relative humidity. This system provides also support for automatic updating, auto-self calibration and adds some Cloud and Edge offloading of computational features for mapping functionalities. From the tests carried out, it is observed a good performance in terms of functionality, battery durability, compared to other measuring devices, more expensive than our proposal
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