Low-cost Measurement Device Research Articles

Low-Cost Measurement Devices for Education

Low-Cost Measurement Devices for Education

Modelling the spatial pattern of heatwaves in the city of Bern using a land use regression approach

Heatwaves have been the deadliest weather extreme events in Europe in the last decades. People living in cities are especially prone to such events due to the urban heat island (UHI) effect which increases the heat stress in urban surroundings especially during calm, steady, and radiation intensive synoptic situations. Since official measurement stations in cities are scarce, studies on spatial patterns of UHIs often rely on satellite data, hobby meteorologists' data, or on model outputs. Additionally, analyses of spatial UHI patterns using point-based measurements need adequate and cost-effective methods for spatial interpolation. In this study, air temperature data retrieved by 60 low cost measurement devices (LCD) are used to model the spatial pattern of the UHI with a land use regression (LUR) approach in Bern, Switzerland. For this purpose, 14 spatial variables with different buffer radii were calculated to evaluate their effect on the UHI and to interpolate the air temperature data. As a result, three models covering three different heatwaves at nighttime were developed. Given good model performance throughout the different scenarios, the here presented study demonstrates the successful interpolation of low cost temperature data by LUR modelling based on publicly accessible spatial information within a city.

Novel, low-cost device to simultaneously measure the electrical conductivity and the Hall coefficient from room temperature up to 600 °C

Abstract. A novel measurement device for simultaneous high temperature measurements of the electrical conductivity and the Hall coefficient has been developed. Simulations were used to design a suitable screen-printed planar platinum heating structure that generates temperatures of up to 600 ∘C by Joule heating. Simulations of the temperature distribution have been validated using thermal imaging. With the hardware setup of two permanent magnetic yoke systems with a magnetic flux density of ±760 mT, the electrical conductivity and the charge carrier densities of a silicon wafer and a gold film were measured, as examples of a typical semiconductor with low charge carrier densities but high mobility and a metal representing materials with very high charge carrier densities but moderate mobilities, respectively. Measurements were compared with data from the literature to validate the functionality of the novel, low-cost measurement device.

Evaluation and application of a low-cost measurement network to study intra-urban temperature differences during summer 2018 in Bern, Switzerland

The understanding of intra-urban air temperature variations is crucial to assess strategies for cities' adaptation to impacts of present and future anthropogenic climate change. Depending on extensive measurement networks, high-resolution air temperature measurements in urban environments are challenging due to high instrumentation and maintenance costs. Here, we present a low-cost measurement device (LCD) consisting of a temperature logger and a custom-made, naturally ventilated radiation shield. Besides intercomparisons with automated weather stations (AWS) at three reference sites during record-dry summer 2018, we tested the potential of the devices using a network of 79 LCDs to assess the intra-urban variability of urban heat island (UHI) patterns in the city of Bern, Switzerland. We found positive mean measurement biases between LCDs and AWS of 0.61 to 0.93 K (RMSE: 0.78 to 1.17 K) during daytime, of which up to 82.8% of the variance could be explained statistically by solar irradiance (radiative heating) and wind speed (insufficient ventilation). During night, average measurement biases were markedly lower and eventually negative with −0.12 to 0.23 K (RMSE: 0.19 to 0.34 K). Our results highlight the importance of sensor intercomparisons being conducted at multiple locations with differing urban land-cover, structure, and metabolism given that biases varied considerably between the reference sites. Data retrieved by the city-wide measurement network showed that the LCD approach is well suited for the analysis of spatiotemporal UHI patterns during night and adds considerable value compared to the few existing AWS in detecting fine-scale air temperature variability. In conclusion, the current LCD measurement approach represents a valuable option for cost-effective analyses of urban air temperature variability across multiple scales, which may be of particular value for the development, appliance, and monitoring of adaptation strategies to climate change in cities with restricted financial resources.

Citizen-Based Air Quality Monitoring: The Impact on Individual Citizen Scientists and How to Leverage the Benefits to Affect Whole Regions

Air pollution is a serious problem that is causing increasing concern among European citizens. It is responsible for more than 400,000 premature deaths in Europe each year and considerably damages human health, agriculture, and the natural environment. Despite these facts, the readiness and power of citizens to take actions is limited. To address this challenge, the citizen science project CAPTOR was launched in 2016. Using low-cost measurement devices, citizens in three European testbeds supported the monitoring of tropospheric ozone. This paper presents the results from 53 interviews with involved residents and shows that the active involvement of individuals in a complex process such as measuring tropospheric ozone can have important impacts on their knowledge and attitudes. In an attempt to expand the benefits of low-cost air quality sensors from an individual to a regional level, certain preconditions are key. Strong support in assuring data quality, visibility of the collected data in online and offline media, broad dissemination of results, and intensified communication with political decision-makers are needed.

A low-cost measurement device for recording perceptions of thermal comfort

In this article, we describe the implementation of a low-cost device that registers perceptions of thermal comfort. The parameters of relative humidity (RH), temperature, thermal sensation (cold, cool, neutral, warn, hot) and clothing worn by people are collected. The design and validation of the device in an indoor environment are explained, and the calibration curves of the temperature and relative humidity sensors are obtained. The measurement results for the device from 10 people are shown. The study was carried out in the village of Imata (high Andean zone), at 4700 masl in the south of Peru.

Low Cost Sensor Networks: How Do We Know the Data Are Reliable?

The plausibility of data from networks of low-cost measurement devices is a growing and important contentious issue. Informal networks of low-cost devices have particularly come to prominence for air quality monitoring. The contentious point is the believability of data without regular on-site calibration, since this is a specialist task and the costs very quickly become much larger than the cost of installation in the first place. This Sensor Issues suggests that approaches to the problem that involve appropriate use of independent information have the potential to resolve the contention. Ideas are illustrated particularly with reference to low-cost sensor networks for air quality measurement.

Implementation of an embedded system for real-time detection of rotor bar failures in induction motors

In this work, the implementation of an embedded system for real-time detection of rotor bar failures in induction motor has been realized. The device is a prototype measurement device which can detect broken rotor bars on the field without any additional setup or third-party software. This study has focused to derive a new method from previous studies on diagnosing of rotor failures and developed a microcontroller based embedded measurement device. A new method which is combining Fast Fourier Transform and Grey Relational Analyses to get best diagnosis results has been developed for an embedded system within a compact and low-cost measurement device. Although, there are some computer-based techniques and motor drivers that can detect internal failures of induction motor, there is no such a measurement device that can do all process by itself.

A respiratory monitoring device based on clavicular motion

Respiratory rate is one of the key vital signs yet unlike temperature, heart rate or blood pressure, there is no simple and low cost measurement device for medical use. Here we discuss the development of a respiratory sensor based upon clavicular motion and the findings of a pilot study comparing respiratory rate readings derived from clavicular and thoracic motion with an expiratory breath flow reference sensor. Simultaneously sampled data from resting volunteers (n = 8) was analysed to determine the location of individual breaths in the data set and from these, breath periods and frequency were calculated. Clavicular sensor waveforms were found to be more consistent and of greater amplitude than those from the thoracic device, demonstrating good alignment with the reference waveform. On comparing breath by breath periods a close agreement was observed with the reference, with mean clavicular respiratory rate R2 values of 0.89 (lateral) and 0.98 (longitudinal-axis). This pilot study demonstrates the viability of clavicular respiratory sensing. The sensor is unobtrusive, unaffected by bioelectrical or electrode problems and easier to determine and more consistent than thoracic motion sensing. With relatively basic signal conditioning and processing requirements, it could provide an ideal platform for a low-cost respiratory monitor.

On-site determination of formaldehyde: A low cost measurement device for museum environments

A trapping reagent for formaldehyde, based on the pararosaniline reaction, was evaluated as a method of determination of formaldehyde in the aqueous or vapour phase. Collection of formaldehyde vapour relied upon passive diffusion of formaldehyde into the trapping media and quantitative results were obtained without the need for liquid impingers, bubblers or active sampling pumps. Moreover, a novel, hand-held absorption spectrophotometric measurement device was designed to provide on-site, quantitative measurements. It is proposed that the full measurement system devised would be ideally suited to specific sampling applications such as those found in museum enclosures.

Data Requirements for Enhanced Digital Maps in an Advanced Curve-Speed Warning System

The development of map database specifications that will enable or improve driver safety assistance systems is a topic of active research. In this context, data requirements are proposed for an advanced curvespeed warning system. Both the content of the database and the accuracy of the needed road-geometry data are addressed. First, some possible drawbacks of previous proposals in this field are sketched. Then, a model is presented to compute the highest safe speed of a road section, given three distinct submodels: vehicle dynamic, infrastructure characteristics, and driver behavior. A case study illustrates how this model may greatly improve driver suitability of curve-speed warning—control driver assistance. A sensitivity analysis formally demonstrates that the requirements concerning road-geometry data are compatible with existing low-cost measurement devices. Finally, some critiques and additions to previous works concerning map database enhancements are formulated.