Rate Meter Research Articles

The HP(3,α) dose response of direct reading survey meters

Direct reading survey meters, designed for the measurement of shallow dose rates, are commercially available. Examples of such instruments include the Fluke 451B, the BOT P200 m with SM20 probe, the Eberline RO-2A and the RAM-Ion. We investigated the potential use of these instruments, as eye lens dose rate meters, with the addition of low-Z filters of suitable thicknesses. Their responses to 90Sr/90Y beta particles and to photons of varied qualities, as functions of angles of incidence, were measured. It was determined that most instruments can be suitably modified to operate as useful eye-lens dose rate meters. Their use in the field could assist radiation protection professionals in the assessment of radiological risk to the lens of the eye. This will allow recommendations on appropriate PPE and dosimetry in individual workplace settings.

Trigger and data acquisition system of the High Energy Particle Detector on board the CSES-02 satellite

This contribution describes the system performing the trigger and the readout of the PMTs for the High Energy Particle Detector (HEPD-02) onboard the second satellite of the China Seismo Electromagnetic Satellite (CSES-02) mission.CSES is a project developed to research the ionospheric perturbations associated with earthquakes. The mission aims at building a network of multi-instrument satellites to conduct a thorough study of ionospheric phenomena.The HEPD-02 is designed to detect cosmic rays, i.e., electrons and protons, along with light nuclei, in the energy range between a few MeV and a few hundreds of MeV. The instrument consists of a tracker, a trigger and a calorimeter surrounded by a veto.All scintillating detectors are readout by a single board which also issues and manages the trigger signals for the whole apparatus. The HEPD-02 trigger system must be extremely versatile because along the orbit of CSES-02 particle fluxes span several orders of magnitude and data acquisition must guarantee the measurement of energy spectra with a high duty cycle. The HEPD-02 trigger system features concurrent trigger configurations and prescaling capability to match the amount of data the instrument can process and send to the ground. Each trigger pattern is optimized after scientific requirements about the field of view and the nature of particles impinging in HEPD-02, with prescaling settings suitably adjusted.All the trigger configurations will be monitored by rate meters. In addition, a trigger configuration dedicated to gamma-rays will be tracked on a time basis of 10 ms, to measure photon fluxes in the MeV-tens of MeV energy range and provide sensitivity for Gamma Ray Bursts. We provide a comprehensive description of the design criteria and the architecture of the trigger system.

Study on the Application of the GTAW Process in Strengthening the Welding Quality of Short Duplex Stainless Pipe

This study focuses on the results of the welding process when the Taguchi method is added to the design of experimental welding parameters when creating the welding procedure for gas tungsten arc welding (GTAW) by ASME Code for duplex stainless steel (UNS31803). A Vickers hardness tester is employed to collect and convert the tensile strength data for each test piece (weld bead, base material, and heat-affected area). A ferritic rate meter can quickly determine the ferric contents, which affect corrosion resistance and susceptibility to cracking. The test data are entered into the Taguchi technique to analyze the influence of each component on the welding quality. The L9 (34) orthogonal table is used to design the parameters for the experiment. We fixed the same shielding gas and flow rate. Backing gas at root, workpiece clamping angle, heat input, and interlayer temperature are employed as control factors for the four essential variables of the GTAW process. The ideal set of quality analysis and optimization parameters can be found. The welding parameters could be used to improve the welding quality of thin and short duplex stainless steel pipe fittings during argon welding.

Perceptions and experiences of Congolese midwives implementing a low-cost battery-operated heart rate meter during newborn resuscitation.

Background900,000 newborns die from respiratory depression each year; nearly all of these deaths occur in low- and middle-income countries. Deaths from respiratory depression are reduced by evidence-based resuscitation. Electronic heart rate monitoring provides a sensitive indicator of the neonate's status to inform resuscitation care, but is infrequently used in low-resource settings. In a recent trial in the Democratic Republic of the Congo, midwives used a low-cost, battery-operated heart rate meter (NeoBeat) to continuously monitor heart rate during resuscitations. We explored midwives' perceptions of NeoBeat including its utility and barriers and facilitators to use.MethodsAfter a 20-month intervention in which midwives from three facilities used NeoBeat during resuscitations, we surveyed midwives and conducted focus group discussions (FGDs) regarding the incorporation of NeoBeat into clinical care. FGDs were conducted in Lingala, the native language, then transcribed and translated from Lingala to French to English. We analyzed data by: (1) coding of transcripts using Nvivo, (2) comparison of codes to identify patterns in the data, and (3) grouping of codes into categories by two independent reviewers, with final categories determined by consensus.ResultsEach midwife from Facility A used NeoBeat on an estimated 373 newborns, while each midwife at facilities B and C used NeoBeat an average 24 and 47 times, respectively. From FGDs with 30 midwives, we identified five main categories of perceptions and experiences regarding the use of NeoBeat: (1) Providers' initial skepticism evolved into pride and a belief that NeoBeat was essential to resuscitation care, (2) Providers viewed NeoBeat as enabling their resuscitation and increasing their capacity, (3) NeoBeat helped providers identify flaccid newborns as liveborn, leading to hope and the perception of saving of lives, (4) Challenges of use of NeoBeat included cleaning, charging, and insufficient quantity of devices, and (5) Providers desired to continue using the device and to expand its use beyond resuscitation and their own facilities.ConclusionMidwives perceived that NeoBeat enabled their resuscitation practices, including assisting them in identifying non-breathing newborns as liveborn. Increasing the quantity of devices per facility and developing systems to facilitate cleaning and charging may be critical for scale-up.

Mass flow prediction in a refrigeration machine using artificial neural networks

Measuring mass flow rate in refrigeration systems with flow meters can be expensive when taking into account the cost of the equipment itself and the costs related to installation and maintenance. A mode based on Artificial Neural Networks can be used to predict the value of the mass flow, at a low cost, through easily observed and measured parameters, like temperatures. Additionally, well-known correlations to calculate parameters that directly influence the mass flow rate can be used as input data for the model to improve its accuracy. Within this context, the present study aims to develop a Multilayer Perceptrons model to predict the mass flow rate of a refrigeration systems. The model developed was optimized using one hidden layer with four neurons, Adam as the optimizer and softplus as the activation function. Later, it is presented an alternative mass flow rate meter, using an Artificial Neural Network model programmed in a microcontrolled circuit with only three temperatures as inputs. To develop the model, experimental data were collected in a refrigeration machine at several operating points. Step disturbances were introduced in the mass flow rate to produce transient data. Two different data sets were considered in the training process. The first data set contained only steady-state data and in the second data set, there were steady-state plus transient data. The mass flow rate estimated through the proposed model presented an average error of 0.79 % when considering steady-state and transient data in the training process, and 0.81 % when considering only steady-state data in the training procedure. The final embedded system developed predicted the mass flow rate with an average error of 1.22 %.

The new method for hydraulic calculations of a district heating (DH) network

How to estimate the exact value of pressure losses within a district heating (DH) network been in service for decades, which a pump at pumping station should compensate to achieve maximum benefits and the lowest costs relative to the scenario of the started process of transition to 4th generation district heating (4GDH)? Geographic Information System (GIS) software Zulu© was used to model a DH network and evaluate how specific location will affect hot water flow rates. Pressure, roughness and hydraulic resistance profiles were plotted using hydraulic optimisation software ZuluThermo©– GIS Zulu© add-in. While the new arrangement does not reduce pressure losses themselves, the corrected arrangement provides economic advantage due to lower operation costs and more stable hydraulic profiles. That means that end sections of DH network between the transmission line and consumers become more effective. By calculating pressure loss and temperature degradation the method also allows to detect an optimum location to connect a new consumer where the minimum modernisation is needed. Working with data-driven network models makes it possible to obtain a lot of positive effects at the same time including the main - the DH utility sells more heat and becomes more profitable as the losses are lower. • To ensure low-temperature energy supply, its consumption for pumping is assessed. • Steady-state calculation method is used to evaluate pressure and flow distribution. • To verify, portable ultrasonic flow rate meter&traditional pressure sensors are used. • Electricity consumption is decreased by 394.74 kW, the saving effect is up to 6%. • Effect is achieved by lowering losses, clarifying friction factor&relative roughness.

Assessment of Background Gamma Radiation Level in Selected Dump Site of Niger Delta, Nigeria

Our environment has been exposed to ionizing radiation from indiscriminate dumping of refuse which is seen as unending and unpreventable challenge on earth. Radiation level and exposure risks in some selected dump site in Rivers state have been calculated using radiation exposure rate meter (Radalert-100). Rate of exposure measured at Ignatius Ajuru University of Education (IAUE) and its environment ranged from 0.005±0.0001 to 0.016±0.003 mRh-1 with mean value of 0.015±0.002 mRh-1 and that measured at Igwuruta ranged from 0.009±0.001 to 0.048±0.003 mRh-1 its mean value is 0.015±0.002 mRh-1. For All, the exposure rate measured ranged from 0.009±0.0001 to 0.015±0.002 mRh-1 its mean value is 0.012±0.004 mRh-1. The exposure rates measured in the three dump site are relatively equal and slightly higher than the recommended permissible limit of 0.013 mRh-1. Estimation of the mean absorbed doses from the exposure rates for Ignatius Ajuru University of Education, Igwuruta and Aluu are 127.72±31.26, 125.91±18.35 and 175.64±41.61 nGyh-1 respectively, its mean absorbed doses are 1.16, 1.18 and 1.11 mSvy-1 respectively. The annual effective dose equivalent calculated is 0.20±0.03, 0.19±0.03 and 0.19±0.03 mSvy-1. The excess lifetime cancer risk estimated ranged from 0.68±0.11, 0.68±0.10 and 0.68±0.10 respectively, they are all above the recommended values 0.29x10ˉ3 in all the sampling locations. Following the result from the radiation level of the dump site, no immediate radiation risk is expected, but there could be a long term effects on those living around the dump side.

Wearable Microfluidic Sensor for the Simultaneous and Continuous Monitoring of Local Sweat Rates and Electrolyte Concentrations.

Temperature elevation due to global warming increases the risks of dehydration, which can induce heat-related illness. Proper rehydration with appropriate amounts of water and electrolytes is essential to aid body fluid homeostasis. Wearable sweat sensors which can monitor both the sweat rate and sweat electrolyte concentration may be an effective tool for determining appropriate rehydration. Here, we developed a novel potentially wearable sensor that can monitor both the local sweat rate and sweat electrolyte concentration continuously. The new device includes a system with a short microfluidic pathway that guides the sweat appearing on the skin to a small space in the device to form a quantifiable droplet. The sweat rate is assessed from the time for the droplet to appear and droplet volume, while an integrated electric sensor detects the sodium chloride concentration in each sweat droplet. We demonstrated that this new device could record both the flow rates of artificial sweat and its sodium chloride concentration in ranges of human sweating with an accuracy within ±10%. This is equivalent to the accuracy of commercially available sweat rate meters and sweat ion sensors. The present study provides a new perspective for the design of wearable sensors that can continuously monitor sweat rates and sweat electrolyte concentrations for potential application to a healthcare device.

Uncertainties of measurements in radiation protection

Abstract On September 1st, 2001, the Austrian standard OENORM S 5255-1 with the title “Uncertainties of measurements and limiting values in radiation protection – Part 1: Basics” was published. A part 2 of the standard with the subtitle “Assessment of measurements with regard to limiting values” was published on April 1st, 2002. Part 1 of the standard is a consequent application of the “Guide to the expression of uncertainty in measurement” (GUM) for measurements in radiation protection. It contains a summary of the most important definitions and mathematical methods, which are relevant for measurements in radiation protection. An important prerequisite is the standardisation of the coverage factor k = 1 for measurements in radiation protection. Finally, the use of the standard is demonstrated by a detailed example there (dose rate meter). First, the uncertainty of a dose rate meter is stated, using only information on tolerances available e. g. from instrument specifications. Additionally, the strategies to reduce the uncertainty and the necessary detailed knowledge of the dose rate meter are demonstrated. Part 2 of the standard gives a simple concept for interpretation of limits using the uncertainties calculated based on part 1 of the standard.

Construction of the Maximum Oxygen Intake Regression Equations for Exercise Training on Respiration and Heart Rate.

To explore the correlation between the maximum percentage heart rate and the maximum percentage oxygen intake, provide an evaluation basis for heart rate for the assessment of exercise load intensity. Four boys and 4 girls were randomly selected, aged 26.25 ± 2.12 years old with good health, good cardiopulmonary function, no other medical history, and irregular physical training history. The subject measured the first 30 min of rest at 25°C at room temperature, kept awake and static, and the heart rate was measured as the quiet heart rate in the state. Prepredicted maximum heart rate and health index were determined according to the Polar s810 heart rate table instructions. Prepredicted maximum heart rate and health index were measured three consecutive times and reliability analysis was performed on three measurements. The regression equations were established by a stepwise method with data represented that all metrics were tested for normality for fitness index and maximum oxygen intake compared using a paired t test with a significance level of P < 0.05. The results showed that the highest value of VO2max motor cardiopulmonary test was 47.83 ml/(kg·min), the lowest was 35.06 ml/(kg·min), the two-step test was 44.50 ml/(kg·min), and the lowest was 32.89 ml/(kg min).With a positive correlation between the postexercise heart rate and the maximum oxygen intake, the maximum oxygen intake value can be indirectly inferred using the heart rate after the exercise and the work completed by the exercise. The results measured by two-step test have some accuracy and can be used to speculate the maximum oxygen intake in the ordinary young population. The polar heart rate meter allows subjects to indirectly measure the maximum oxygen intake in silence, requiring less equipment and being easy to operate. The indirect measurement of the maximum oxygen intake can be used for the monitoring of competitive sports and national fitness.

DETERMINATION OF THE NEUTRON CONTAMINATION DURING BRAIN RADIOTHERAPY USING A MODERATED-BORON TRIFLUORIDE DETECTOR AND THE MCNP MONTE CARLO CODE.

This study aimed to determine the neutron dose equivalent to the thyroid gland and eye lens in brain tumor radiation therapy with 15- and 18-MV three-dimensional conformal methods (3D-CRT). A Monte Carlo simulation was performed using the Monte Carlo N-particle transport code to calculate neutron fluence and ambient dose equivalent (H*(10)). Afterward, these parameters were measured using a model NRD roentgen equivalent in man (REM) neutron detector (Thermo Electron Corporation, USA) equipped with Eberline's ASP-2e rate meter. Finally, the organ neutron dose equivalent was obtained by applying depth corrections to the measured ambient dose equivalent at the distance of the organ center from the central beam axis. The ratio of the out-of-field photon dose equivalent, measured previously, to the neutron dose equivalent in the eye lens was high due to its proximity to the radiation field. In contrast, this ratio remained unexpectedly high in the thyroid gland that is far from the central beam axis (about 15cm). The calculated neutron parameters agreed with the measurements. The present study findings indicate that external field photon dose is the main source of thyroid gland biological effects in radiotherapy of brain tumors. In addition, it is appropriate to apply the model NRD REM neutron detector for measuring neutron contamination from high-energy linear accelerators inside and outside the treatment field.

The Second AGILE MCAL Gamma-Ray Burst Catalog: 13 yr of Observations

Abstract We present the results of a systematic search and analysis of GRBs detected by the Astrorivelatore Gamma ad Immagini LEggero (AGILE) MiniCALorimeter (MCAL; 0.4–100 MeV) over a time frame of 13 yr, from 2007 to 2020 November. The MCAL GRB sample consists of 503 bursts triggered by MCAL, 394 of which were fully detected onboard with high time resolution. The sample consists of about 44% short GRBs and 56% long GRBs. In addition, 109 bursts triggered partial MCAL onboard data acquisitions, providing further detections that can be used for joint analyses or triangulations. More than 90% of these GRBs were also detected by the AGILE Scientific RateMeters (RMs), providing simultaneous observations between 20 keV and 100 MeV. We performed spectral analysis of these events in the 0.4–50 MeV energy range. We could fit the time-integrated spectrum of 258 GRBs with a single power-law model, resulting in a mean photon index 〈β〉of−2.3. Among them, 43 bursts could also be fitted with a Band model, with peak energy above 400 keV, resulting in a mean low-energy photon index 〈α〉 = −0.6, a mean high-energy photon index 〈β〉 = −2.5, and a mean peak energy 〈E p 〉 = 640 keV. The AGILE MCAL GRB sample mostly consists of hard-spectrum GRBs, with a large fraction of short-duration events. We discuss properties and features of the MCAL bursts, whose detections can be used to perform joint broad-band analysis with other missions, and to provide insights on the high-energy component of the prompt emission in the tens of mega electron volt energy range.

Perceptions and experiences of Congolese midwives implementing a low-cost battery-operated heart rate meter during newborn resuscitation

Perceptions and experiences of Congolese midwives implementing a low-cost battery-operated heart rate meter during newborn resuscitation

Test stand for pulsed jet actuator command and characterization

The paper presents a test stand for characterization of a new design of a Pulsed Jet Actuator. The aim of the work was to characterize the performance of the PJA in terms of air parameters in the air supply line and velocity at the PJA outlet. To perform a detailed characterization of the system performance, the test bench comprised: a pressure reductor, a mass flow rate controller, a mass flow rate meter, a pressure sensor, a fast pressure sensor, a flow temperature sensor and a Constant Temperature Anemometer. The PJA was commanded by a real time controller with Field Programmed Gate Array architecture. The experimental results show good agreement with the results of Computational Fluid Dynamics simulations performed at the design stage of the PJA. It has been found that the flow parameters at the PJA nozzle outlet match the design goals. The developed bench testing procedures will be used for silent conditions tests of the PJA system integrated into a leading edge of a wind tunnel model.

Dose estimates of occupational radiation exposure during radioguided surgery of Tc-99m-PSMA-labeled lymph nodes inrecurrent prostate cancer.

[99mTc]Tc-PSMA-based radioguided surgery (TPRS) represents a curative approach for localized relapse of prostate cancer. For its simplified regulatory permission, the radiation protection authorities require a 99mTc- activity below the exemption limit of 10 MBq at the time of surgery. Our aim was to determine the optimal amount of radioactivity (OAR) to comply with that limit and to estimate the maximum number of TPRS procedures per year and surgeon without triggering the full monitoring obligations. In this retrospective study, a dose rate meter was calibrated using measurements on phantoms and from recently injected (1 min p. i.) patients to determine the activity in the patient from measured dose rates. The effective half-life of 99mTc-PSMA-I&S in patients was determined from repeated dose rate measurements to estimate dose parameters of relevance for radiation protection. External exposures of the surgeons were measured with personal dosimeters calibrated in Hp(10). The surgeon's finger dose Hp(0.07) is estimated from radioactivity measured in resected lymph nodes. Potenzial incorporations were estimated for an activity of 10 MBq. From the first 6 subsequent patients, an effective half-life of 4.15 h was observed. Assuming an operation time 24 h p. i., the OAR was 550 MBq. Operations lasting in average 2 h in a distance of 0.25 m to the patient imply a body dose for surgeons of 4.16 µSv per procedure. Based on these estimates, the surgeon's Hp(10) is less than 1 mSv per year with up to 241 operations per year. Hp(0.07) and potential incorporation of activity do not lead to further limitations. All radiation protection regulations are met with adherence to OAR recommended here without triggering the full monitoring obligations from radiation protection regulations.

Radiation Protection Evaluations Following the Installations of Two Cardiovascular Digital X-ray Fluoroscopy Systems

Acceptance testing and commission are essential elements of the quality assurance program for imaging equipment. We present the results of a performance evaluation of Flat Panel-Based Cardiovascular Fluoroscopy X-ray Systems as a part of acceptance testing and commissioning. Measurements were obtained using a calibrated dose rate meter, patient equivalent phantoms, and Leeds image quality test tools. The results were compared with the manufacturer and European acceptability criteria. The entrance surface air kerma (ESAK) rate ranged from 8.0 to 12.0 mGy min−1 in the continuous mode and from 0.01 to 0.04 mGy fr−1 in the pulsed mode of operation. Detector-input air kerma rates ranged from 0.29 to 0.39 mGy min−1 in continuous mode and from 0.02 to 0.07 µGy fr−1 in pulsed mode. Fluoroscopy device half-value layer (HVL) ranged from 2.5 to 3.0 mm Al, and the low resolution ranged from 0.9 to 1.3%. The spatial resolution limit was double that of the image intensifier (2.4 to 3.6) lp/mm. Flat-panel fluoroscopy demonstrated superior image quality and dose performance as compared to conventional image intensifier-based fluoroscopy. The quality assurance measurements presented are essential in the rapid evaluation of the imaging system for acceptance testing and commissioning.

Model analysis for differential pressure two-phase flow rate meter in intermittent flow

Multiphase flow rate metering is a challenging problem, specially for flow patterns other than wet-gas. This paper brings forward a new comparative analysis of three differential pressure calibration models suited for liquid dominated two-phase flows, in a total of seven model configurations. First, the models are compared theoretically and classified in terms of the type of input data required. Then, experimental data of over 300 horizontal air–water experiments, for 1” and 2” pipe diameters, supports quantitative analyses of the prediction accuracies and sensitivity of the superficial velocities of gas and liquid to measurement errors in the model input variables. Finally, a method for assessing the decoupled measurement errors for the void fraction and gas velocity is shown, as these variables are typically subject to higher uncertainties. It results that, though the void fraction is shown to be systematically under evaluated in more than 10%, the total mass flow rate is estimated through the Paz et al. (2010) model with an overall root mean squared deviation (RMSD) of 5.75% for the 2” data. Also, the use of gas velocity measurements, even if subject to considerable errors, decreased the RMSD for the gas superficial velocity by more than half for the 1” data.

ASSESSMENT OF OUTDOOR RADIATION EXPOSURE LEVELS AND HUMAN HEALTH RISK IN A MAJOR SCRAP METAL MARKET IN ABUJA

Background: Scrap metal can contain sources of radiation with the associated environmental and health risks. Radioactive substances can become associated with scrap metal in various ways and if not discovered they can be incorporated into steel and non-ferrous metals through the melting process. This can cause health hazards to workers and to the public as well as environmental concerns Objectives: this study aimed at assessing the outdoor radiation exposure levels and human health risk in a major scrap metal market in Abuja, FCT. Method: An in-situ measurement approach was adopted using a factory calibrated Radiagem-2000 Universal Survey Meter and a handheld Global Positioning System (Garmin GPS 76S) equipment. The monitor was suspended in air at one meter above the ground level. Readings were obtained between the hours of 1200 and 1600 hours since the exposure rate meter has a maximum response to environmental radiation within these hours. Results: The results showed that the average values for the outdoor exposure dose rate for the three location ranges from 0.173±0.042 μSv/h to 0.177±0.046 μSv/h with a mean of 0.176±0.045 μSv/h. These values, though, slightly higher than the standard background radiation of 0.133 μSv/h,are below the ICRP maximum permissible limit of 0.57 μSv/h. The results also show that the AEDE values are lower than the ICRP recommended limits of 1.0 mSv/y for the public and 20 mSv/y for occupationally exposed workers. The ELCR ranges from 0.5926 x 10-3 to 0.6049 x 10-3 with a mean of 0.6008 x 10-3 which is 2.1 times higher than the world’s average. The dosage to organs received shows that the testes have the highest dose while the liver has the lowest dose. The result of the dose to the organs showed that all the values are below the international tolerable limits. Conclusion: Generally, The radiological assessment shows that the study area does not constitute any immediate radiological health effect on the workers and the general public due to radiation exposure rate.

BeSafe B2.0 Smart Multisensory Platform for Safety in Workplaces.

Wearable technologies are becoming a profitable means of monitoring a person’s health state, such as heart rate and physical activity. The use of the smartwatch is becoming consolidated, not only as a novelty but also as a very useful tool for daily use. In addition, other devices, such as helmets or belts, are beneficial for monitoring workers and the early detection of any anomaly. They can provide valuable information, especially in work environments, where they help reduce the rate of accidents and occupational diseases, which makes them powerful Personal Protective Equipment (PPE). The constant monitoring of the worker’s health can be done in real-time, through temperature, falls, noise, impacts, or heart rate meters, activating an audible and vibrating alarm when an anomaly is detected. The gathered information is transmitted to a server in charge of collecting and processing it. In the first place, this paper provides an exhaustive review of the state of the art on works related to electronics for human activity behavior. After that, a smart multisensory bracelet, combined with other devices, developed a control platform that can improve operators’ security in the working environment. Artificial Intelligence and the Internet of Things (AIoT) bring together the information to improve safety on construction sites, power stations, power lines, etc. Real-time and historic data is used to monitor operators’ health and a hybrid system between Gaussian Mixture Model and Human Activity Classification. That is, our contribution is also founded on the use of two machine learning models, one based on unsupervised learning and the other one supervised. Where the GMM gave us a performance of 80%, 85%, 70%, and 80% for the 4 classes classified in real time, the LSTM obtained a result under the confusion matrix of 0.769, 0.892, and 0.921 for the carrying-displacing, falls, and walking-standing activities, respectively. This information was sent in real time through the platform that has been used to analyze and process the data in an alarm system.

Investigation into the performance of dose rate measurement instruments used in non-governmental networks

In the aftermath of a nuclear or radiological accident, an extended mapping of reliable dose rate values is of key importance for any governmental decision and countermeasures. Presently, numerous dosimetry network stations, operated by the national governments of the member states in Europe, provide such dose rate data on an hourly basis. Nevertheless, there are large areas in Europe that are not covered at all by these early warning networks and other areas that show only a low density of governmental network stations. Hence, there may be a significant lack of information in case of a nuclear or radiological emergency. As a consequence of the Fukushima Daiichi nuclear power plant accidents in 2011, a number of non-governmental radiation monitoring networks (NRMN) appeared on the internet, providing dose rate data based on stationary as well as on mobile measurements of ionizing radiation by laypersons. Especially the mobile detectors are able to cover large areas in short time. Therefore, it is of considerable importance to investigate the feasibility of using dose rate data from non-governmental networks as a complementary input to the European Radiological Data Exchange Platform (EURDEP). Within the European Metrology Program for Innovation and Research (EMPIR), the project 16ENV04 “Preparedness” has studied the metrological relevance of such non-governmental dose rate data (also called crowd-sourced radiological monitoring) in the most comprehensive way so far. Sixteen different dose rate detector systems (in general 4 of each type, plus 2 types with 2 detectors, i.e. 68 detectors in total) used in NRMN have been investigated for the reliability of their data and the corresponding networks, and their data provision to the public were analyzed. The most relevant performance parameters of dosimetry systems (detector's inherent background, energy dependence and linearity of the response as well as the response to secondary cosmic radiation, the sensitivity to small increases of the dose rate and finally the stability of the detector's indication at various climatic conditions - temperature and humidity) have been investigated for fourteen representative types of non-governmental dose rate measuring instruments. Results of this comprehensive performance study of the simple, light-weighted and cheap dose rate meters used in NRMN, and conclusions on the feasibility of using their data for governmental monitoring in case of a nuclear or radiological emergency are presented.